What does it mean?

General Overview

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 or model.

Description of Code P0281

The OBD II trouble code P0281 is described as a contribution or imbalance in cylinder number 7. Essentially, this code indicates that cylinder number seven in the firing order is experiencing a fuel supply-related issue.

This is a common code across all manufacturers, although some models may have a specific faulty part or installation error. For each vehicle, it is recommended to check online technical service bulletins (TSBs) to find the factory-recommended repair procedure.

Operation and Role of the PCM

The Powertrain Control Module (PCM) monitors the output power of each cylinder by comparing the acceleration or increase in crankshaft speed during the power stroke. When one or more cylinders provide less power than the others, the P0281 trouble code is then set.

A technician can replicate this test by removing the spark plugs one by one while the engine is running to observe the RPM drop on each cylinder. All cylinders should show an RPM variation of less than 5% from each other. Any cylinder deviating from this range should be repaired, as prolonged imbalance can lead to more significant damage.

---

Symptoms

Observable Signs

Symptoms associated with code P0281 may include:

• Check engine light on with P0281 code stored
• Reduced power and acceleration
• Rough idle
• Decreased fuel economy

---

Causes

Power Issue in Cylinder Number 7

Based on experience, this code refers to insufficient power produced in cylinder number seven. This lack of power can be caused by several factors:

Possible Causes

• Electrical Issue: A fault (high or low voltage) in the injector may be detected by the system.
• Lack of Fuel: The cylinder is not receiving enough fuel.
  • The injector may be completely faulty.
  • It may be dripping a small amount of fuel instead of spraying a normal cone-shaped pattern, due to dirt or contamination in the injector’s inlet filter.
• Faulty Electrical Connector: Corrosion on terminals or pushed-back pins on the injector connector.
• Dirty or Clogged Injector

---

Diagnostic and Repair Procedure

Initial Inspection

1. Visual Check
   • Inspect the electrical connector of the fuel injector.
   • Check the wiring harness for signs of corrosion or pushed-back pins.
   • Examine the injector for bent pins.
2. Fault Correction
   • Repair any identified faults.
   • Apply dielectric grease to the connector terminals and reinstall it properly.

Operational Tests

3. Sound Test
   • Start the engine and use a long screwdriver to touch the injector blade.
   • Listen for the characteristic “clicking” sound indicating injector operation.
   • Absence of this sound may mean the injector is not powered or is faulty.
4. Electrical Measurement
   • Using a wire probe on a voltmeter, measure the voltage on the injector’s red power wire.
   • The voltage should match the battery voltage.
   • If no voltage is detected, there may be a break in the wiring between the injector and the fuel pump relay.
   • If voltage is present and the injector is operating, it is likely clogged.

Injector Flushing Procedure

5. Cleaning
   • Purchase a “direct fuel injector flush kit” available at auto parts stores. This kit typically includes a pressurized can of cleaner and a hose fitting for the injection rail.
   • Remove the fuel pump fuse (located on the driver’s side fender in the relay box).
   • Start the engine and let it run until fuel pressure is depleted and the engine stalls.
   • Pinch the fuel return line using a needle-nose vise grip.
   • Remove the Schrader valve from the fuel pump test port and install the test hose.
   • Connect the cleaner can to the hose and wait a few seconds for the pressurized cleaner to fill the injection rail.
   • Restart the engine and let it run until it stalls.
   • Remove the cleaning hose and reinstall the Schrader valve.
   • Remove the vise grip from the return line and replace the fuel pump fuse.

Reset and Final Verification

6. Code Clearing
   • Use a code reader to clear the trouble code and reset the PCM.
   • Start the engine again to verify the issue is resolved.
   • If rough idle persists and the code returns, the fuel injector likely needs replacement.

---

This issue should be resolved promptly to avoid potential engine damage. Be sure to follow these diagnostic and repair steps to restore proper operation of cylinder number 7.

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 OBD fault code P0282 is a generic powertrain code common to all vehicles. Although the code reference is the same, the repair procedure may vary somewhat by manufacturer.

This code implies that the Powertrain Control Module (PCM) has experienced a low voltage situation involving the fuel injector for cylinder #8 in the firing order.

In short, this fuel injector is malfunctioning for one of many reasons. It is important to diagnose and repair this type of issue as soon as possible.

When a fuel injector malfunctions, it causes ripples throughout the system, meaning the engine’s operating parameters change due to mixed signals being sent to the PCM.

If the fuel injector’s spray pattern is reduced, a lean mixture results. The ripple effect begins. The oxygen sensor signals a lean mixture to the PCM. In response, it enriches the fuel mixture for all cylinders. Fuel economy drops.

The cylinder with the faulty injector causes a lean mixture which in turn causes a higher cylinder head temperature leading to detonation. The knock sensor detects the detonation, signals the PCM which responds by retarding the timing. Now the engine runs poorly and lacks power.

This isn’t the end of the ripple effect, but it reflects the general idea.

Cross-section diagram of a typical automotive fuel injector

Symptoms

Symptoms displayed for a P0282 code may include:

The check engine light illuminates and the P0282 code is set
The engine will run rougher than normal
A lack of power
A significant drop in fuel economy will result

Causes

Possible causes of this DTC include:

Dirty fuel injector supplying cylinder number eight
Faulty fuel injector
Clogged fuel injector
Open or short in the fuel injector harness
Loose or corroded fuel injector connector

Diagnosis / Repair

Generally, this type of problem is either a loose or corroded electrical connector on the injector, a clogged (dirty or blocked) injector, or a bad injector that needs replacement.

In over 45 years, I have found that loose or corroded connectors were the cause of the electrical fault most of the time. I have only found a few cases where the low voltage wiring became shorted or open (when it hasn’t been disturbed).

The majority of electrical problems were related to the alternator, starter solenoid wiring, oxygen sensor wiring due to the immediate proximity of the exhaust, and the battery. The majority of electrical work involved correcting items installed by the customer, such as high-power stereo chains and other poorly installed parts or equipment.

Fuel injectors are powered by the fuel pump relay. The PCM activates the relay when the key is turned on. This means that as long as the key is on, the injectors have power.

The PCM activates the injector by providing the ground at the necessary time and for the appropriate duration.

Check the connector on the fuel injector. This is a plastic connector attached to the injector with a metal clip around the connector. Pull on the connector to see if it comes off easily. Remove the wire tie and disconnect the connector from the injector.
Inspect the harness connector for corrosion or pushed-back pins. Ensure the two blades are not bent in the injector itself. Correct any faults and apply dielectric grease and install the electrical connector.
Start the engine and listen to the injector to ensure it is operating. Use a long screwdriver on the injector and the handle to your ear and you can hear it clearly. If it doesn’t make a very audible “clicking” noise, it either has no power or it has failed.
If it wasn’t clicking, remove the connector from the injector and check for power with a voltmeter. No power means the wiring from the fuel pump relay is faulty or has a loose connection. If it is powered, probe both terminals on the harness connector and if the PCM injector driver is working, the voltmeter will show rapid pulses. If pulses are observed, replace the injector.
If the injector was operating, it is either clogged or dirty. Try cleaning it first. The injector flush kit is inexpensive and will benefit the remaining injectors, potentially preventing a recurrence. If flushing doesn’t resolve the issue, the injector must be replaced.

Buy an “in-line” fuel injector flush kit online or at an auto parts store. It will consist of a can of high-pressure injector cleaner and a hose with one end for the injector cleaner can’s threads.

Pull the fuse for the fuel pump.
Start the vehicle and let it run until it dies from lack of fuel.
Remove and plug the fuel return line attached to the fuel pressure regulator. This is to prevent the cleaner from going back into the fuel tank.
Remove the Schrader valve in the test port of the fuel rail. Install the fuel line from the flush kit onto this test port. Screw the can of high-pressure fuel injector cleaner onto the fuel line of the flush kit.
Start the engine and let it run until it runs out of fuel. It will run solely on the can of cleaner.
When the engine stops, turn off the key, remove the line from the flush kit, and replace the Schrader valve. Install the fuel pump fuse.

What Does It Mean?

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

The fault code P0283 is a generic code (common to all manufacturers) indicating higher-than-average current consumption by the fuel injector serving cylinder number eight.

The engine cylinder injector #8 is malfunctioning or not working at all due to a circuit issue. Note that while this code is common to all vehicles, the prognosis may vary by manufacturer.

For example, they may have encountered issues with a batch of fuel injectors or another faulty circuit component specific to their particular vehicles.

This type of problem is best addressed as soon as possible to avoid damaging other internal components. A faulty fuel injector will affect the spark plug, cause knocking, also impact the oxygen sensor and catalytic converter, as well as several other components.

Go online and access the technical service bulletins (TSB) for your specific vehicle. Look for all TSBs related to P0283 and their suggested repair procedures.

Cross-section diagram of a typical automotive fuel injector

Symptoms

Symptoms displayed for a P0283 code may include:

The malfunction indicator light will illuminate and the P0283 code will be set
Engine idles poorly
Fuel economy will suffer
There will be a lack of power indicated by poor acceleration

Causes

Potential causes of this DTC include:

Faulty wiring harness from PCM to injector
Faulty electrical connector on the fuel injector
Fuel injector with internal short causing high voltage draw
Clogged or dirty fuel injector

Diagnostic and Repair Procedure

From my experience over the years, the problem is usually a corroded or loose fuel injector connector, or a faulty fuel injector.

A loose connector causes excessive resistance, thus increasing the voltage required for operation. The powertrain control module (PCM) wiring harness is not easily accessible and, left intact, is rarely faulty.

The fuel injector, on the other hand, is susceptible to a variety of issues. The number one problem is fuel with anhydrous ethanol content. This fuel additive reduces consumption of oil-based fuel.

The water vapor produced with E10 anhydrous ethanol has a negative effect on fuel injectors. They depend on fuel for lubrication. Water vapor reduces the friction-reducing properties of gasoline and causes premature wear of the injector.

Small engine manufacturers do not approve the use of ethanol-based fuels as they significantly reduce the lifespan of a small engine.

Inspect the electrical connector on the fuel injector. Look for bent or pushed-back pins. Apply dielectric grease and push the electrical connector onto the fuel injector. Ensure it is snug and the metal spring retaining clip is in place.
Start the engine. Place a long screwdriver handle against your ear and the tip on the fuel injector. A clicking sound indicates a working injector. No sound means the opposite.
Disconnect the fuel injector. Using an ohmmeter, check the resistance between the two male terminal blades. A good injector will have 0.5 to 2.0 ohms. Higher or lower ohms indicates an injector with an internal short.
If the resistance is correct and the injector can be heard operating, the next step is to try cleaning the injector. If cleaning fails to restore normal injector operating parameters, the only alternative is to replace the injector.
Purchase a direct injection cleaning kit consisting of a can of cleaner and an injection hose. Pull the fuel pump fuse and start the engine. Let it run until it stalls.
Remove the Schrader valve from the fuel pressure test port on the fuel rail. Install the hose onto the test port.
Pinch the fuel return line directly behind the fuel pressure regulator using a needle-nose vise grip.
Open the cleaner bottle to increase pressure in the supply rail.
Start the engine and let it run on the fuel injection cleaner bottle until it stalls.
Turn off the key and remove the cleaning hose from the test port. Install the Schrader valve, remove the vise grip handles from the return line, and install the fuel pump fuse.
Use a common code scanner to clear the fault codes. Start the engine. If the code returns, replace the injector.

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 OBD II trouble code P0284 is described as Cylinder 8 Contribution/Balance. Essentially, this code indicates that cylinder number eight in the firing order is experiencing a fuel-related issue.

 

It is also a generic code, meaning it is common to all manufacturers. The reference is the same; however, the manufacturer of a specific model may have encountered a defective part or installation error.

Always access Technical Service Bulletins (TSBs) online for your specific year and make vehicle. Look for related TSBs and the factory-recommended repair procedure.

The Powertrain Control Module (PCM) monitors the power output of each cylinder by comparing the acceleration or increase in crankshaft speed during the power stroke of each cylinder.

When one or more cylinders provide less power than the rest of the cylinders, the P0284 trouble code is set.

While the PCM performs this test to determine if a fuel injector is functioning correctly, an automotive technician can perform a similar test to locate internal engine problems. By pulling one spark plug at a time while the engine is running, they note the RPM drop on each cylinder.

All cylinders should be within 5% of each other. Any cylinder with a lesser RPM drop needs repair. Both tests are similar in that they both compare crankshaft RPM.

This is an issue that should be addressed as soon as possible to avoid any potential damage.

Cross-section diagram of a typical automotive fuel injector

 

Symptoms

Symptoms displayed for a P0284 code may include:

Check Engine Light illuminated and P0284 code set
Reduced power and acceleration
Rough idle
Decreased fuel economy

Causes

Based on my experience, this code refers to less power produced in cylinder number eight. An electrical problem would set a code for a high or low voltage situation for that injector.

A lack of fuel for cylinder number eight is the most likely cause. The injector may have completely failed or it is dribbling a small amount of fuel rather than the normal cone-shaped spray. This would be due to dirt or contamination of the inlet filter on the injector.

Possible faulty electrical connector on the fuel injector due to terminal corrosion or pushed-back pins
Dirty or clogged fuel injector
Fuel injector failure

Diagnostic and Repair Procedure

Inspect the electrical connector on the fuel injector. Look at the harness side for corrosion or pushed-back pins. Check the injector for bent pins. Correct any defects and add dielectric grease to the connector terminals and reinstall the connector
Start the engine. Use a long screwdriver with the handle to your ear and the blade on the injector, and listen for the characteristic “clicking” noise indicating it is operating. No noise means either it is not powered or the injector has failed
Using a wire probe on a voltmeter, probe the red power wire at the injector. It should indicate battery voltage. If no voltage is present, there is an open in the wiring between the injector and the fuel pump relay. If voltage is present and the injector is operating, it is likely clogged and needs cleaning
Purchase a “direct fuel injector flush kit” from an auto parts store. It consists of a pressurized can of injector cleaner and a hose fitting for the injection rail
Remove the fuel pump fuse from the main fuse and relay box on the driver’s side fender
Start the engine and let it run until fuel pressure is depleted and it stalls
Pinch the fuel return line using a needle-nose vise grip
Remove the Schrader valve from the fuel pump test port on the fuel rail. Install the hose onto the test port.
Thread the can of injector cleaner onto the hose and wait a few seconds for the pressurized cleaner to fill the injection rail. Start the engine and let it run on the cleaner until it stalls.
Remove the cleaning hose from the test port and reinstall the Schrader valve. Remove the vise grip from the return line and install the fuel pump fuse.
Clear the trouble code and reset the PCM using a common code reader
Start the engine. If the rough idle continues and the code returns, replace the fuel injector.

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 OBD fault code P0285 is a generic powertrain code common to all vehicles. Although the code reference is the same, the repair procedure may vary somewhat by manufacturer.

This code implies that the Powertrain Control Module (PCM) has experienced a low voltage situation involving the fuel injector for cylinder #9 in the firing order.

In short, this fuel injector is malfunctioning for one of many reasons. It is important to diagnose and repair this type of issue as soon as possible.

When a fuel injector malfunctions, it causes ripples throughout the system, meaning the engine’s operating parameters change due to mixed signals being sent to the PCM.

If the fuel injector’s spray pattern is reduced, a lean mixture results. The ripple effect begins. The oxygen sensor reports a lean mixture to the PCM. In response, it enriches the fuel mixture for all cylinders. Fuel economy drops.

The cylinder with the faulty injector causes a lean mixture which in turn causes a higher cylinder head temperature leading to detonation. The knock sensor detects the detonation, signals the PCM which responds by retarding the timing. Now the engine runs poorly and lacks power.

This isn’t the end of the ripple effect, but it reflects the general idea.

Cross-section diagram of a typical automotive fuel injector

Symptoms

Symptoms displayed for a P0285 code may include:

Check Engine Light illuminated and P0285 code set
Engine will run rougher than normal
Lack of power
A significant drop in fuel economy will result

Causes

Possible causes for this DTC include:

Dirty fuel injector supplying cylinder number nine
Faulty fuel injector
Clogged fuel injector
Open or short in the fuel injector harness
Loose or corroded fuel injector connector

Diagnosis / Repair

Generally, this type of problem is either a loose or corroded electrical connector on the injector, a clogged (dirty or blocked) injector, or a bad injector needing replacement.

In over 45 years, I’ve found that loose or corroded connectors were the cause of the electrical fault most of the time. I’ve only found a few cases where the low voltage wiring became shorted or open (when it hasn’t been disturbed).

The majority of electrical problems were related to the alternator, starter solenoid wiring, oxygen sensor wiring due to its immediate proximity to the exhaust, and the battery. The majority of electrical work involved correcting items installed by the customer, such as high-power stereo chains and other improperly installed parts or equipment.

Fuel injectors are powered by the fuel pump relay. The PCM activates the relay when the key is turned on. This means that as long as the key is on, the injectors have power.

The PCM activates the injector by providing the ground at the necessary time and for the appropriate duration.

Check the connector on the fuel injector. This is a plastic connector attached to the injector with a metal clip around the connector. Pull on the connector to see if it comes off easily. Remove the wire tie and disconnect the connector from the injector.
Inspect the harness connector for corrosion or pushed-back pins. Ensure the two blades are not bent in the injector itself. Correct any faults and apply dielectric grease and install the electrical connector.
Start the engine and listen to the injector to ensure it is operating. Use a long screwdriver on the injector and the handle to your ear and you can hear it clearly. If it doesn’t make a very audible “clicking” noise, it either has no power or it has failed.
If it wasn’t clicking, remove the connector from the injector and check for power with a voltmeter. No power means the wiring from the fuel pump relay is faulty or has a loose connection. If it has power, probe both terminals on the harness connector and if the PCM injector driver is working, the voltmeter will show rapid pulses. If pulses are observed, replace the injector.
If the injector was operating, it is either clogged or dirty. Try cleaning it first. The injector flush kit is inexpensive and will benefit the remaining injectors, potentially preventing a recurrence. If flushing doesn’t resolve the issue, the injector must be replaced.

Buy an “in-line” fuel injector flush kit online or at an auto parts store. It will consist of a can of high-pressure injector cleaner and a hose with one end for the injector cleaner can’s threads.

Pull the fuse for the fuel pump.
Start the vehicle and let it run until it dies from lack of fuel.
Remove and plug the fuel return line attached to the fuel pressure regulator. This is to prevent the cleaner from going back into the fuel tank.
Remove the Schrader valve in the test port on the fuel rail. Install the fuel line from the flush kit onto this test port. Screw the can of high-pressure fuel injector cleaner onto the fuel line from the flush kit.
Start the engine and let it run until it runs out of fuel. It will run solely on the can of cleaner.
When the engine stops, turn off the key, remove the line from the flush kit, and replace the Schrader valve. Install the fuel pump fuse.

What Does It Mean?

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

The fault code P0286 is a generic code (common to all manufacturers) indicating above-average current consumption by the fuel injector serving cylinder number nine.

The engine cylinder injector #9 is malfunctioning or not working at all due to a circuit issue. It should be noted that although this code is common to all vehicles, the prognosis may vary by manufacturer.

For example, they may have encountered issues with a batch of fuel injectors or another faulty circuit component limited to their specific vehicles.

This type of problem is best addressed as soon as possible to avoid damaging other internal components. A faulty fuel injector will affect the spark plug, cause knocking, also impact the oxygen sensor and catalytic converter, as well as several other components.

Go online and access the technical service bulletins (TSB) for your specific vehicle. Look for TSBs related to P0286 and their suggested repair procedure.

Cross-section diagram of a typical automotive fuel injector

Symptoms

Symptoms displayed for a P0286 code may include:

The malfunction indicator light will illuminate and the P0286 code will be set
The engine idles roughly
Fuel economy will suffer
There will be a lack of power indicated by poor acceleration

Causes

Potential causes of this DTC include:

Faulty electrical wiring harness from PCM to injector
Faulty electrical connector on the fuel injector
Fuel injector with internal short circuit causing high voltage draw
Clogged or dirty fuel injector

Diagnostic and Repair Procedure

From my experience over the years, the problem is usually a corroded or loose fuel injector connector, or a faulty fuel injector.

A loose connector causes excessive resistance, thus increasing the voltage required for operation. The powertrain control module (PCM) wiring harness is not easily accessible and, left untouched, is rarely faulty.

The fuel injector, on the other hand, is susceptible to a variety of issues. The number one problem is fuel with anhydrous ethanol content. This fuel additive reduces oil-based fuel consumption.

The water vapor produced with E10 anhydrous ethanol has a negative effect on fuel injectors. They depend on fuel for lubrication. Water vapor reduces the friction-reducing properties of gasoline and causes premature wear of the injector.

Small engine manufacturers do not approve the use of ethanol-based fuels as they significantly reduce the lifespan of a small engine.

Inspect the electrical connector on the fuel injector. Look for bent or pushed-back pins. Apply dielectric grease and push the electrical connector onto the fuel injector. Ensure it is snug and the metal spring retaining clip is in place.
Start the engine. Place a long screwdriver handle against your ear and the tip on the fuel injector. A clicking sound indicates a working injector. No sound means the opposite.
Disconnect the fuel injector. Using an ohmmeter, check the resistance between the two male terminal blades. A good injector will have 0.5 to 2.0 ohms. More or fewer ohms indicates an injector with an internal short circuit.
If the resistance is correct and the injector can be heard operating, the next step is to try cleaning the injector. If cleaning fails to restore normal injector operating parameters, the only alternative is to replace the injector.
Purchase a direct injection cleaning kit consisting of a can of cleaner and an injection hose. Pull the fuel pump fuse and start the engine. Let it run until it stalls.
Remove the Schrader valve from the fuel pressure test port on the fuel rail. Install the hose onto the test port.
Pinch the fuel return line directly behind the fuel pressure regulator using a needle-nose vise.
Open the cleaner bottle to increase pressure in the fuel rail.
Start the engine and let it run on the fuel injection cleaner bottle until it stalls.
Turn off the key and remove the cleaning hose from the test port. Install the Schrader valve, remove the vise grips from the return line, and install the fuel pump fuse.
Use a common code scanner to clear the fault codes. Start the engine. If the code returns, replace the injector.

What Does It Mean?

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

The OBD II fault code P0287 is described as Cylinder 9 Contribution/Balance. Essentially, this code indicates that cylinder number nine in the firing order is experiencing a fuel-related issue.

It is also a generic code, meaning it is common to all manufacturers. The reference is the same; however, the manufacturer of a specific model may have encountered a defective part or installation error.

Always access online Technical Service Bulletins (TSBs) for your specific vehicle year and model. Look for related TSBs and the factory-recommended repair procedure.

The Powertrain Control Module (PCM) monitors the power output of each cylinder by comparing the acceleration or increase in crankshaft speed during the power stroke of each cylinder.

When one or more cylinders provide less power than the rest of the cylinders, the P0287 fault code is set.

While the PCM performs this test to determine if a fuel injector is functioning correctly, an automotive technician can perform a similar test to locate internal engine problems. By pulling one spark plug at a time while the engine is running, they note the RPM drop on each cylinder.

All cylinders should be within 5% of each other. Any cylinder with a lesser RPM drop should be repaired. Both tests are similar in that they both compare crankshaft RPM.

This is an issue that should be resolved as soon as possible to avoid any potential damage.

Cross-section diagram of a typical automotive fuel injector

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 OBD fault code P0288 is a generic powertrain code common to all vehicles. Although the code reference is the same, the repair procedure may vary somewhat by manufacturer.

 

This code implies that the Powertrain Control Module (PCM) has experienced a low voltage situation involving the fuel injector for cylinder #10 in the firing order.

In short, this fuel injector is malfunctioning for one of many reasons. It is important to diagnose and repair this type of issue as soon as possible.

When a fuel injector malfunctions, it causes ripples throughout the system, meaning the engine’s operating parameters change due to mixed signals being sent to the PCM.

If the fuel injector’s spray pattern is reduced, a lean mixture will result. The ripple effect begins. The oxygen sensor reports a lean mixture to the PCM. In response, it enriches the fuel mixture for all cylinders. Fuel economy drops.

The cylinder with the faulty injector causes a lean mixture which in turn causes a higher cylinder head temperature leading to detonation. The knock sensor detects the detonation, signals the PCM which responds by retarding the timing. Now the engine runs poorly and lacks power.

This isn’t the end of the ripple effect, but it reflects the general idea.

Cross-section diagram of a typical automotive fuel injector

Symptoms

Symptoms displayed for a P0288 code may include:

Check Engine Light illuminated and P0288 code set
Engine will run rougher than normal
Lack of power
A significant drop in fuel economy will result

Causes

Possible causes of this DTC include:

Dirty fuel injector supplying cylinder number ten
Faulty fuel injector
Clogged fuel injector
Open or short in the fuel injector harness
Loose or corroded fuel injector connector

Diagnosis / Repair

Generally, this type of problem is either a loose or corroded electrical connector on the injector, a clogged (dirty or blocked) injector, or a bad injector requiring replacement.

In over 45 years, I have found that loose or corroded connectors were the cause of the electrical fault most of the time. I have only found a few instances where the low voltage wiring became shorted or open (when it hasn’t been disturbed).

The majority of electrical problems were related to the alternator, starter solenoid wiring, oxygen sensor wiring due to the immediate proximity of the exhaust, and the battery. The majority of electrical work involved correcting items installed by the customer, such as high-power stereo chains and other poorly installed parts or equipment.

Fuel injectors are powered by the fuel pump relay. The PCM activates the relay when the key is turned on. This means that as long as the key is on, the injectors have power.

The PCM activates the injector by providing the ground at the necessary time and for the appropriate duration.

Check the connector on the fuel injector. This is a plastic connector attached to the injector with a metal clip around the connector. Pull on the connector to see if it comes off easily. Remove the wire tie and disconnect the connector from the injector.
Inspect the harness connector for corrosion or pushed-back pins. Ensure both blades are not bent on the injector itself. Correct any faults and apply dielectric grease and install the electrical connector.
Start the engine and listen to the injector to ensure it is operating. Use a long screwdriver on the injector and the handle to your ear and you can hear it clearly. If it doesn’t make a very audible “clicking” noise, it either has no power or it has failed.
If it wasn’t clicking, remove the connector from the injector and check for power with a voltmeter. No power means the wiring from the fuel pump relay is faulty or has a loose connection. If it is powered, probe both terminals on the harness connector and if the PCM injector driver is working, the voltmeter will show rapid pulses. If pulses are observed, replace the injector.
If the injector was operating, it is either clogged or dirty. Try cleaning it first. The injector flush kit is inexpensive and will benefit the remaining injectors, potentially preventing a recurrence. If flushing doesn’t solve the problem, the injector must be replaced.

Buy an “in-line” fuel injector flush kit online or at an auto parts store. It will consist of a can of high-pressure injector cleaner and a hose with one end for the threads of the injector cleaner can.

Pull the fuse for the fuel pump.
Start the vehicle and let it run until it dies from lack of fuel.
Remove and plug the fuel return line attached to the fuel pressure regulator. This is to prevent the cleaner from going back into the fuel tank.
Remove the Schrader valve from the test port on the fuel rail. Install the fuel line from the flush kit onto this test port. Screw the can of high-pressure fuel injector cleaner onto the fuel line of the flush kit.
Start the engine and let it run until it runs out of fuel. It will run solely on the cleaner can.
When the engine stops, turn off the key, remove the line from the flush kit, and replace the Schrader valve. Install the fuel pump fuse.