What Does It Mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to most OBD-II equipped vehicles, including but not limited to VW Volkswagen, Dodge, Ram, Kia, Chevrolet, GMC, Jaguar, Ford, Jeep, Chrysler, Nissan, etc. Although generic, the specific repair steps may vary by make/model.

A stored P021C code means that the Powertrain Control Module (PCM) has detected a malfunction in the injection timing circuit for a specific engine cylinder. In this case, the cylinder in question is cylinder nine. Consult a reliable vehicle information source to determine the exact location of cylinder number nine in the vehicle where the P021C has been stored.

Based on my experience, a P021C code is stored exclusively in vehicles equipped with diesel engines. Today’s clean-burning (direct injection) diesel engines require extremely high levels of fuel pressure.

Due to this high fuel pressure level, only qualified personnel should attempt to diagnose or repair the high-pressure fuel system.

When unit injectors are used, the high-pressure injection pump is driven by the engine’s timing chain and timed based on the crankshaft and camshaft positions. Whenever the engine’s crankshaft and camshafts reach a certain point, the high-pressure injection pump is pulsed; resulting in an extreme degree (up to 35,000 psi) of fuel pressure.

Common rail direct injection systems are timed using a common high-pressure fuel rail and individual solenoids for each cylinder. In this type of application, the PCM or a standalone diesel injection controller is used to control injector timing.

Variations in camshaft and/or crankshaft timing alert the PCM to inconsistencies in the specific cylinder’s injection timing and prompt a stored P021C code. Some vehicles may require multiple ignition cycles with a failure for this type of code to be stored and a malfunction indicator lamp to illuminate.

Related injection timing codes include cylinders 1 through 12: P020A, P020B, P020C, P020D, P020E, P020F, P021A, P021B, P021C, P021D, P021E, and P021F.
Code Severity and Symptoms

All codes related to the high-pressure fuel injection system should be considered severe and addressed with a degree of urgency.

Symptoms of a P021C engine code may include:

Engine misfires, sagging, or stumbling
General lack of engine performance
Characteristic diesel fuel odor
Reduced fuel efficiency

Causes

Possible causes of this P021C code include:

Faulty fuel injection solenoid
Open or shorted wiring and/or connectors in the fuel injector control circuit
Bad fuel injector
Engine timing component failure
Crankshaft or camshaft position sensor (or circuit) failure

Diagnostic and Repair Procedures

I would need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source to diagnose a P021C code.

Start with a visual inspection of components and wiring harnesses related to the high-pressure fuel system. Look for signs of fuel leaks as well as damage to wiring or connectors.

Check for Technical Service Bulletins (TSBs) related to the vehicle, symptoms, and codes in question. If such a TSB is found, it will provide very useful information for diagnosing this code.

Now, I connect the scanner to the vehicle’s diagnostic port and retrieve all stored trouble codes and freeze frame data. I like to note this information as it may prove beneficial during the diagnosis. Then, I would clear the codes and test-drive the vehicle to see if the code resets. If crankshaft and/or camshaft position sensor codes are stored, diagnose and repair them before attempting to diagnose the injector timing code.
If the code resets:

If the vehicle in question is equipped with a common rail injection system, use the DVOM and vehicle information source to test the injector solenoid for the cylinder in question. Any component not meeting manufacturer specifications should be replaced before continuing. Once suspected parts are repaired/replaced, clear any codes that may have been stored during testing and test-drive the vehicle until the PCM enters readiness mode or the code resets. If the PCM enters readiness mode, you know the repair was successful. If the code resets – you can assume you still have a problem.

If the injector solenoid meets specifications, disconnect the controller and use the DVOM to test the system circuits for shorts or opens. Repair or replace any system circuits that do not meet manufacturer specifications according to the pinout chart located in your vehicle information source.

Unit injector failure can almost always be attributed to an engine timing component failure or some type of high-pressure fuel system leak.

A P021C should only be diagnosed by a qualified technician due to extreme fuel pressure

Determine the type of high-pressure fuel system the vehicle is equipped with before starting your diagnosis

What Does It Mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to most OBD-II equipped vehicles, including but not limited to VW Volkswagen, Dodge, Ram, Kia, Chevrolet, GMC, Jaguar, Ford, Jeep, Chrysler, Nissan, etc. Although generic, the specific repair steps may vary by make/model.

A stored P021D code means that the Powertrain Control Module (PCM) has detected a malfunction in the fuel injection timing circuit for a specific engine cylinder. In this case, the cylinder in question is cylinder ten. Consult a reliable vehicle information source to determine the exact location of cylinder number ten in the vehicle where the P021D was stored.

Based on my experience, a P021D code is stored exclusively in vehicles equipped with diesel engines. Today’s clean-burning (direct injection) diesel engines require extremely high levels of fuel pressure.

Due to this high fuel pressure level, only qualified personnel should attempt to diagnose or repair the high-pressure fuel system.

When unit injectors are used, the high-pressure injection pump is driven by the engine’s timing chain and timed based on the crankshaft and camshaft positions. Whenever the engine’s crankshaft and camshafts reach a certain point, the high-pressure injection pump is pulsed; resulting in an extreme degree (up to 35,000 psi) of fuel pressure.

Common rail direct injection systems are timed using a common high-pressure fuel rail and individual solenoids for each cylinder. In this type of application, the PCM or a standalone diesel injection controller is used to control injector timing.

Variations in camshaft and/or crankshaft timing alert the PCM to inconsistencies in the specific cylinder injection timing and prompt a stored P021D code. Some vehicles may require multiple ignition cycles with a failure for this type of code to be stored and a malfunction indicator lamp to illuminate.

Related fuel injection timing codes include cylinders 1 through 12: P020A, P020B, P020C, P020D, P020E, P020F, P021A, P021B, P021C, P021D, P021E, and P021F.
Code Severity and Symptoms

All codes related to the high-pressure fuel injection system should be considered severe and addressed with a degree of urgency.

Symptoms of a P021D engine code may include:

Engine misfires, sagging, or stumbling
General lack of engine performance
Characteristic diesel fuel odor
Reduced fuel efficiency

Causes

Possible causes of this P021D code include:

Faulty fuel injection solenoid
Open or shorted wiring and/or connectors in the fuel injector control circuit
Bad fuel injector
Failed engine timing component
Crankshaft or camshaft position sensor (or circuit) failure

Diagnostic and Repair Procedures

I would need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source to diagnose a P021D code.

Start with a visual inspection of components and wiring harnesses related to the high-pressure fuel system. Look for signs of fuel leaks as well as damage to wiring or connectors.

Check for Technical Service Bulletins (TSBs) related to the vehicle, symptoms, and codes in question. If such a TSB is found, it will provide very useful information for diagnosing this code.

Now, connect the scanner to the vehicle’s diagnostic port and retrieve all stored trouble codes and freeze frame data. I like to record this information as it may prove beneficial during diagnosis. Next, I would clear the codes and test-drive the vehicle to see if the code resets. If crankshaft position sensor and/or camshaft position sensor codes are stored, diagnose and repair them before attempting to diagnose the injector timing code.
If the code resets:

If the vehicle in question is equipped with a common rail injection system, use the DVOM and the vehicle information source to test the injector solenoid for the cylinder in question. Any component not meeting manufacturer specifications should be replaced before proceeding. Once suspected parts are repaired/replaced, clear any codes that may have been stored during testing and test-drive the vehicle until the PCM enters readiness mode or the code resets. If the PCM enters readiness mode, you know the repair was successful. If the code resets – you can assume you still have a problem.

If the injector solenoid meets specifications, disconnect the controller and use the DVOM to test the system circuits for shorts or opens. Repair or replace system circuits that do not meet manufacturer specifications according to the pinout chart located in your vehicle information source.

Unit injector failure can almost always be attributed to a failed engine timing component or some type of high-pressure fuel system leak.

A P021D should only be diagnosed by a qualified technician due to extreme fuel pressure
Determine the type of high-pressure fuel system the vehicle is equipped with before starting your diagnosis

What does it mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to most OBD-II equipped vehicles, including but not limited to VW Volkswagen, Dodge, Ram, Kia, Chevrolet, GMC, Jaguar, Ford, Jeep, Chrysler, Nissan, etc. Although generic, the exact repair steps may vary by make/model.

A stored P021E code means that the Powertrain Control Module (PCM) has detected a malfunction in the injection timing circuit for a specific engine cylinder. In this case, the cylinder in question is cylinder eleven. Consult a reliable vehicle information source to determine the exact location of cylinder number eleven in the vehicle where P021E was stored.

Based on my experience, a P021E code is stored exclusively in vehicles equipped with diesel engines. Today’s clean-burning (direct injection) diesel engines require extreme levels of fuel pressure.

Due to this high level of fuel pressure, only qualified personnel should attempt to diagnose or repair the high-pressure fuel system.

When unit injectors are used, the high-pressure injection pump is driven by the engine’s timing chain and set based on the position of the crankshaft and camshafts. Whenever the engine’s crankshaft and camshafts reach a certain point, the high-pressure injection pump is pulsed; resulting in an extreme degree (up to 35,000 psi) of fuel pressure.

Common rail direct injection systems are timed using a common high-pressure fuel rail and individual solenoids for each cylinder. In this type of application, the PCM or a standalone diesel injection controller is used to control injector timing.

Variations in camshaft and/or crankshaft timing alert the PCM to inconsistencies in the specific cylinder’s injection timing and prompt a stored P021E code. Some vehicles may require multiple ignition cycles with a failure for this type of code to be stored and a malfunction indicator lamp to illuminate.

Related injection timing codes include cylinders 1 through 12: P020A, P020B, P020C, P020D, P020E, P020F, P021A, P021B, P021C, P021D, P021E, and P021F.
Code Severity and Symptoms

All codes related to the high-pressure fuel injection system should be considered severe and treated with a degree of urgency.

Symptoms of a P021E engine code may include:

Engine misfires, sagging, or stumbling
General lack of engine performance
Characteristic diesel fuel odor
Reduced fuel efficiency

Causes

Possible causes of this P021E code include:

Faulty fuel injection solenoid
Open or shorted wiring and/or connectors in the fuel injector control circuit
Bad fuel injector
Failed engine timing component
Crankshaft or camshaft position sensor (or circuit) failure

Diagnostic and Repair Procedures

I would need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source to diagnose a P021E code.

Start with a visual inspection of components and wiring harnesses related to the high-pressure fuel system. Look for signs of fuel leaks as well as damage to wiring or connectors.

Check for Technical Service Bulletins (TSBs) related to the vehicle, symptoms, and codes in question. If such a TSB is found, it will provide very useful information for diagnosing this code.

Now, connect the scanner to the vehicle’s diagnostic port and retrieve all stored trouble codes and freeze frame data. I like to note this information as it may prove beneficial as the diagnosis progresses. Then, I would clear the codes and test-drive the vehicle to see if the code resets. If crankshaft and/or camshaft position sensor codes are stored, diagnose and repair them before attempting to diagnose the injector timing code.

If the code resets:

If the vehicle in question is equipped with a common rail injection system, use the DVOM and the vehicle information source to test the injector solenoid for the cylinder in question. Any component not meeting manufacturer specifications should be replaced before continuing. Once suspected parts are repaired/replaced, clear all codes that may have been stored during testing and test-drive the vehicle until the PCM enters readiness mode or the code resets. If the PCM enters readiness mode, you know the repair was successful. If the code resets – you can assume you still have a problem.

If the injector solenoid meets specifications, disconnect the controller and use the DVOM to test the system circuits for shorts or opens. Repair or replace system circuits that do not meet manufacturer specifications according to the pinout chart located in your vehicle information source.

Unit injector failure can almost always be attributed to a failed engine timing component or some type of high-pressure fuel system leak.

A P021E should only be diagnosed by a qualified technician due to extreme fuel pressure
Determine the type of high-pressure fuel system the vehicle is equipped with before starting your diagnosis

What Does It Mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to most OBD-II equipped vehicles, including but not limited to VW Volkswagen, Dodge, Ram, Kia, Chevrolet, GMC, Jaguar, Ford, Jeep, Chrysler, Nissan, etc. Although generic, the exact repair steps may vary by make/model.

A stored P021F code means that the Powertrain Control Module (PCM) has detected a malfunction in the injection timing circuit for a specific engine cylinder. In this case, the cylinder in question is cylinder twelve. Consult a reliable vehicle information source for the exact location of cylinder number twelve in the vehicle where P021F was stored.

Based on my experience, a P021F code is stored exclusively in vehicles equipped with diesel engines. Today’s clean-burning (direct injection) diesel engines require extreme levels of fuel pressure.

Due to this high level of fuel pressure, only qualified personnel should attempt to diagnose or repair the high-pressure fuel system.

When unit injectors are used, the high-pressure injection pump is driven by the engine’s timing chain and timed according to the crankshaft and camshaft positions. Whenever the engine’s crankshaft and camshafts reach a certain point, the high-pressure injection pump is pulsed; resulting in an extreme degree (up to 35,000 psi) of fuel pressure.

Common rail direct injection systems are timed using a common high-pressure supply rail and individual solenoids for each cylinder. In this type of application, the PCM or a standalone diesel injection controller is used to control injector timing.

Variations in camshaft and/or crankshaft timing alert the PCM to inconsistencies in the specific cylinder injection timing and prompt a stored P021F code. Some vehicles may require multiple ignition cycles with a failure for this type of code to be stored and a malfunction indicator light to illuminate.

Related injection timing codes include cylinders 1 through 12: P020A, P020B, P020C, P020D, P020E, P020F, P021A, P021B, P021C, P021D, P021E, and P021F.
Code Severity and Symptoms

All codes related to the high-pressure fuel injection system should be considered severe and treated with a degree of urgency.

Symptoms of a P021F engine code may include:

Engine misfires, sagging, or stumbling
General lack of engine performance
Characteristic diesel fuel odor
Reduced fuel efficiency

Causes

Possible causes of this P021F code include:

Faulty fuel injection solenoid
Open or shorted wiring and/or connectors in the fuel injector control circuit
Bad fuel injector
Engine timing component failure
Crankshaft or camshaft position sensor (or circuit) failure

Diagnostic and Repair Procedures

I would need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source to diagnose a P021F code.

Start with a visual inspection of components and wiring harnesses related to the high-pressure fuel system. Look for signs of fuel leaks as well as damage to wiring or connectors.

Check for Technical Service Bulletins (TSBs) related to the vehicle, symptoms, and codes in question. If such a TSB is found, it will provide very useful information for diagnosing this code.

Now, connect the scanner to the vehicle’s diagnostic port and retrieve all stored trouble codes and freeze frame data. I like to note this information as it may prove beneficial during diagnosis. Then, I would clear the codes and test-drive the vehicle to see if the code resets. If crankshaft and/or camshaft position sensor codes are stored, diagnose and repair them before attempting to diagnose the injector timing code.

If the code resets:

If the vehicle in question is equipped with a common rail injection system, use the DVOM and vehicle information source to test the injector solenoid for the cylinder in question. Any component not meeting manufacturer specifications should be replaced before continuing. Once suspected parts are repaired/replaced, clear any codes that may have been stored during testing and test-drive the vehicle until the PCM enters readiness mode or the code resets. If the PCM enters readiness mode, you know the repair was successful. If the code resets – you can assume you still have a problem.

If the injector solenoid meets specifications, disconnect the controller and use the DVOM to test the system circuits for shorts or opens. Repair or replace system circuits that do not meet manufacturer specifications according to the pinout chart located in your vehicle information source.

Unit injector failure can almost always be attributed to an engine timing component failure or some type of high-pressure fuel system leak.

A P021F should only be diagnosed by a qualified technician due to extreme fuel pressure
Determine the type of high-pressure fuel system the vehicle is equipped with before starting your diagnosis

What does it mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to vehicles equipped with OBD-II. Although generic, specific repair steps may vary by make/model.

The throttle position sensor is a potentiometer that measures how much the throttle is open. When the accelerator is opened, the reading (measured in volts) increases.

 

The powertrain control module (PCM) is the main computer controlling the vehicle and it provides a 5-volt reference signal to the throttle position sensor (TPS) and usually a ground as well. A general measurement is: at idle = 0.5 Volts; at full throttle = 4.5 Volts. If the PCM detects that the throttle angle is higher or lower than it should be for a specific RPM, it will set this code. The B refers to a particular circuit, sensor, or area of a specific circuit.

Symptoms

Potential

Symptoms of a P0221 trouble code may include:

Illumination of the malfunction indicator lamp (MIL) (Check Engine Light or Service Engine Soon Light)
Intermittent stumbling during acceleration or deceleration
Puff of black smoke during acceleration
No start

Causes

A P0221 code can mean that one or more of the following events have occurred:

TPS has an intermittent open or short internally
The harness is rubbing and causing an open or short in the wiring
Poor connection to the TPS
Faulty PCM (less likely)
Water or corrosion in the connector or sensor

Possible Solutions

1. If you have access to a scan tool, see what the idle and WOT (wide open throttle) readings are for the TPS. Check if they are close to the specifications mentioned above. If not, replace the TPS and recheck.

2. Look for an intermittent open or short in the TPS signal. To do this, you cannot use a scan tool. You will need an oscilloscope. The reason is that scan tools take samples of many different readings over one or two data lines and might miss an intermittent interruption. Connect your oscilloscope and watch the signal. It should sweep up and down smoothly without glitches or spikes.

3. If no problem has been found, perform a wiggle test. To do this, wiggle the connector and harness while observing the pattern. Does it drop out? If yes, replace the TPS and recheck.

4. If you have no TPS signal, check for the 5-volt reference at the connector. If it is present, check if the ground circuit is open or shorted.

5. Ensure the signal circuit is not at 12V. It should never have battery voltage. If it does, trace the circuit for a short and repair it.

6. Look for water in the connector and replace the TPS if necessary.

What Does This Mean?

The diagnostic code P0222 is a generic powertrain code applicable to vehicles equipped with OBD-II. Although its definition is standard, repair steps may vary depending on the vehicle’s make and model.

This code indicates that the vehicle’s computer has detected excessively low voltage from the throttle position sensor (TPS). In some vehicles, this lower limit is between 0.17 and 0.20 volts (V). The letter B refers to a specific circuit or sensor within the system.

If the signal voltage drops below 0.17 V, the powertrain control module (PCM) records this code. This may be due to an open circuit, a short to ground, or a loss of the 5V reference voltage.

Possible Symptoms

A vehicle affected by this code may exhibit the following symptoms:

• Unstable or excessively low idle
• Misfires or hesitation
• Irregular acceleration (surging)
• Loss of power or acceleration
• Other engine performance-related symptoms

Possible Causes

Code P0222 can be caused by several factors, including:

• Throttle position sensor (TPS) improperly installed or secured
• Short circuit in the TPS circuit
• Faulty TPS sensor
• Failure of the powertrain control module (PCM)

Solutions and Diagnostic Steps

1. Visual Inspection
   • Check the condition of the TPS sensor, wiring, and connectors.
   • Look for damaged, exposed, or shorted wires.
   • Repair or replace faulty components as necessary.
2. TPS Voltage Check
   • Consult the vehicle’s service manual for precise specifications.
   • If the measured voltage is below normal, the sensor may be faulty and require replacement.
3. TPS Adjustment
   • If the sensor was recently replaced, it may require specific adjustment.
   • Some models require precise alignment of the TPS during installation.
4. Code Clearing and Road Test
   • If no symptoms are present, the issue may be intermittent. Clear the code and perform a road test.
   • If the code reappears, carefully inspect the wiring to prevent chafing or accidental grounding.

Conclusion

Code P0222 is related to a malfunction of the throttle position sensor, which can affect engine performance. Thorough inspection and diagnostics help quickly identify the cause of the problem and avoid costly long-term repairs.

What does it mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to OBD-II equipped vehicles. Although generic, specific repair steps may vary by make/model.

When I encountered a stored P0223 code, I found it means the Powertrain Control Module (PCM) detected a high voltage input from the Throttle Position Sensor (TPS) circuit or a specific Pedal Position Sensor (PPS) circuit. B refers to a particular circuit, sensor, or area of a specific circuit.

Consult a reliable vehicle information source (All Data DIY will work) for details about the specific vehicle. This code is only used in vehicles equipped with Drive-By-Wire (DBW) systems.

The PCM controls the DBW system using a throttle actuator motor, one or more pedal position sensors (sometimes called accelerator pedal position sensors), and multiple throttle position sensors. The sensors are provided with a reference voltage (typically 5 volts) and ground. Most TPS/PPS sensors are potentiometer type and complete their respective circuits. A pivoting extension, on the accelerator pedal or throttle shaft, operates the sensor contacts. The sensor resistance changes as contacts move across the sensor circuit board, causing variations in circuit resistance and signal input voltage to the PCM.

If the signal input voltage exceeds a programmed limit, for an extended period under certain conditions, a P0223 code will be stored and a Malfunction Indicator Lamp (MIL) may illuminate.

Symptoms

/ Severity

When this code is stored, the PCM typically enters limp mode. Engine acceleration will be severely limited (if not disabled) in this mode. P0223 code symptoms may include:

Stuck throttle (at any RPM)
Limited or no acceleration
Engine stalling at idle
Hesitation during acceleration
Inoperative cruise control

Causes

Possible causes of this engine code include:

Open or shorted circuits between TPS, PPS and PCM
Faulty TPS or PPS
Corroded electrical connectors
Faulty cable actuator motor

Diagnostic and Repair Procedures

A good starting point is always checking Technical Service Bulletins (TSBs) for your specific vehicle. Your problem might be a known issue with a published manufacturer fix, potentially saving time and money during diagnosis.

I would need access to a diagnostic scanner, digital volt/ohmmeter (DVOM), and vehicle information source like All Data (DIY) to diagnose a P0223 code.

My first diagnostic step would be visual inspection of all cables and connectors related to the system. I also like checking the throttle plate for carbon buildup or damage signs. Excessive carbon buildup, which keeps the throttle body open at startup, can cause P0223 code storage. Clean carbon from throttle body per manufacturer recommendations and repair/replace faulty wiring or components as needed, then retest the DBW system.

Next, I connect the scanner to the vehicle diagnostic port and retrieve all stored trouble codes. I record them in case I need the code storage sequence. I also preserve all related freeze frame data. These notes can prove helpful if P0223 proves intermittent. Now I clear codes and test drive the vehicle. If the code resets, I continue diagnosis

Voltage spikes and inconsistencies between TPS, PPS and PCM can be detected using scanner data stream. Narrow data stream to display only relevant data for faster response. If no spikes/inconsistencies are detected, use DVOM to gather live data from each sensor individually. To gather live data with DVOM, connect test leads to appropriate signal and ground circuits and observe DVOM display during DBW operation. Watch for voltage spikes when throttle is slowly operated from closed to wide open position. Voltage typically ranges from 0.5 volts at closed throttle to 4.5 volts at wide open throttle. If spikes or other irregularities are detected, suspect the tested sensor is faulty. An oscilloscope is also excellent for testing sensor operation.

Additional Diagnostic Notes:

Some manufacturers require throttle body, throttle actuator motor, and all throttle position sensors be replaced together

What does it mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to all vehicles from 1996 onwards (Dodge, Chrysler, Hyundai, Jeep, Mazda, etc.). Although generic, specific repair steps may vary by make/model.

In my personal experience, I’ve found that a stored P0224 code means the Powertrain Control Module (PCM) has detected an intermittent malfunction in the Throttle Position Sensor (TPS) “B” circuit.

The TPS is typically a potentiometer-type sensor that completes a five-volt reference circuit. The TPS is mechanically actuated using an extension of the throttle plate shaft or a specially designed tab on the sensor. When the throttle is opened and closed, the contacts inside the sensor are dragged across a printed circuit board, varying the sensor’s resistance. As the sensor’s resistance changes, the TPS circuit voltage fluctuates. The PCM recognizes these fluctuations as varying degrees of throttle plate actuation.

The PCM uses the input voltage signals from the TPS to calculate fuel distribution and ignition timing. It also uses TPS input data to monitor intake airflow, exhaust oxygen content, Exhaust Gas Recirculation (EGR) function, and engine load percentage.

If the PCM detects a number of intermittent or erratic signals from the TPS over a defined period and under a set of programmed circumstances, a P0224 code will be stored and a Malfunction Indicator Lamp (MIL) may illuminate.
Severity and Symptoms

The TPS plays a significant role in engine operation; therefore, a stored P0224 code should be addressed with some degree of urgency.

Symptoms of a P0224 code may include:

Hesitation during acceleration
Black smoke from the engine exhaust (especially at startup)
Delayed engine starting (particularly during a cold start)
Reduced fuel efficiency
Related stored emission codes may accompany a P0224

Causes

Possible causes of this engine code include:

Faulty or improperly adjusted TPS
Open or shorted TPS “B” wiring or connectors
Binding or damaged throttle plate
Incorrect PCM or PCM programming error

Diagnostic and Repair Procedures

A good starting point is always to check the Technical Service Bulletins (TSBs) for your specific vehicle. Your issue might be a known problem with a published fix from the manufacturer, potentially saving time and money during diagnosis.

I typically use a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable source of vehicle information (like ALLDATA DIY) to diagnose a P0224 code.

Successful diagnosis usually begins with a visual inspection of all wiring and connectors related to the system. I also like to test the throttle plate for signs of coking or carbon damage. Repair or replace any faulty wiring or components as needed, then recheck the throttle body and TPS.

Connect the scanner to the diagnostic connector; retrieve all stored trouble codes and note them for future reference. I also save any associated freeze frame data. My notes often prove useful if the stored code turns out to be intermittent. Then, I would clear the codes and test-drive the vehicle. Continue diagnosis if the code resets. If it doesn’t reset, the condition might need to worsen before a proper diagnosis can be made. Drive the vehicle normally until the PCM enters readiness mode or the code resets.

Proceed by checking the Technical Service Bulletins (TSBs) relevant to the specific malfunction (and vehicle) in question by consulting your vehicle information source. If applicable, use the information in the appropriate TSB to assist in your diagnosis. TSBs can be particularly helpful when diagnosing an intermittent condition.

The scanner’s data stream can provide useful information regarding faults and inconsistencies in the throttle position sensor. If you filter the scanner’s data stream to display only relevant data, you’ll get a more accurate response from the data.

If no issues are detected, use the DVOM to test the TPS. Using the DVOM gives you access to live data if the appropriate test leads are connected to the ground and signal circuits. Watch the DVOM screen while manually operating the throttle. Look for voltage spikes as the throttle is slowly actuated from the closed position to wide-open throttle. Voltage typically ranges from 0.5 volts at closed throttle to 4.5 volts at open throttle. If faults or other inconsistencies are detected, suspect that the tested sensor is faulty or improperly adjusted.

Additional Diagnostic Notes:

If the TPS has been replaced and a P0224 continues to be stored, consult the vehicle information source for TPS adjustment specifications
Use the DVOM (with test leads connected to the ground and signal circuits) to adjust the TPS accurately

What does it mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to OBD-II equipped vehicles. Although generic, specific repair steps may vary by make/model.

The TPS (Throttle Position Sensor) is a potentiometer mounted on the throttle body. It detects the throttle blade angle. As the throttle blade moves, the TPS sends a signal to the PCM (Powertrain Control Module). Typically a three-wire sensor: a 5-volt reference from PCM to TPS, a ground from PCM to TPS, and a signal return from TPS to PCM.

The TPS returns throttle position information to the PCM on this signal wire. When the throttle is closed, the signal is near 0.45 volts. At WOT (Wide Open Throttle), the TPS signal voltage will approach a full 5 volts. When the PCM detects a voltage outside the normal operating range, P0225 sets. The C refers to a particular circuit, a sensor, or an area of a particular circuit.

NOTE: The PCM knows that any significant change in throttle position means a corresponding change in intake manifold pressure (MAP) response. On some models, the PCM will monitor MAP and TPS operation for comparison. This means if the PCM sees a significant percentage change in throttle position, it expects to see a simultaneous response change in intake manifold pressure and vice versa. If it does not see this comparative change, P0225 may be set. This does not apply to all models.

Symptoms

Potential symptoms include:

MIL (Malfunction Indicator Lamp) illumination
Misfires at idle or highway speed
Poor idle quality
May not idle
May start and stall

Causes

Potential causes of code P0225 include:

Sticking throttle return spring
Corrosion on MAP or TPS connectors
Misrouted harness causing chafing
Faulty TPS
Faulty PCM

Possible Solutions

If you have access to a scan tool, with KOEO (Key On Engine Off), monitor the TPS voltage. With the throttle closed, the voltage should be around 0.45 volts. It should gradually sweep up to about 4.5 to 5 volts as you press the throttle. Sometimes only an oscilloscope can capture an intermittent problem in the TPS signal voltage. If you notice a problem in the TPS sweep voltage, replace the TPS.

NOTE: Some TPS sensors require fine adjustment. If you are not comfortable using a DVOM (Digital Volt Ohm Meter) to adjust the new TPS, then it is best to take the vehicle to a shop. If the voltage is not 0.45 volts (+ or – about 0.3 volts) with the throttle closed or if the reading is “stuck,” disconnect the TPS connector. With KOEO, check for the 5-volt reference voltage present at the connector and a good ground. You can check the signal circuit continuity by jumpering a fused wire between the TPS connector ground circuit and the signal circuit. If the TPS reading on the scan tool now reads zero, replace the TPS. However, if it does not change the reading to zero, check for an open or short in the signal wire and if none are found, suspect a faulty PCM. If manipulating the TPS wiring harness causes a change at rest, suspect a faulty TPS.