What does it mean?

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to all vehicles manufactured from 1996 onwards (Ford, Honda, Mazda, Mercedes, VW, etc.). Although generic, specific repair steps may vary by make/model.

If a P0704 code has been stored in your OBD-II vehicle, it simply means the Powertrain Control Module (PCM) has detected a malfunction in the clutch switch input circuit. This code applies exclusively to vehicles equipped with manual transmissions.

Certain manual transmission functions are electronically monitored by the PCM. The gear lever position and clutch pedal position are among these functions. In some models, turbine input and output speed are also monitored to determine the degree of clutch slippage.

The clutch is a mechanical coupling that connects the engine to the transmission. In most cases, it is actuated using a rod (with a pedal at the end) that pushes the piston of a hydraulic clutch master cylinder mounted on the firewall. When the clutch master cylinder is pressed, hydraulic fluid is pushed into the slave cylinder (mounted on the transmission). The slave cylinder actuates the clutch pressure plate, allowing the engine to be engaged and disengaged from the transmission as needed. Some models use a cable clutch, but this type of system is becoming less common. Pressing the pedal with the left foot disengages the transmission from the engine. Releasing the pedal allows the clutch to engage the flywheel, propelling the vehicle in the desired direction.

The main function of the clutch switch is to act as a safety device so the engine does not start with the transmission unintentionally engaged. The clutch switch is primarily designed to interrupt the starter signal (from the ignition switch) so the starter is only activated if the clutch pedal is pressed. The PCM and other controllers also use the clutch switch input for various engine control calculations, automated braking functions, as well as for implementing hill hold and start-stop functions.

The P0704 code relates to the clutch switch input circuit. Consult your vehicle’s service manual or All Data (DIY) for component locations and other specific information regarding this particular circuit for your vehicle.

Symptoms and Severity
Various driving, safety, and traction control functions may be interrupted when a P0704 code is stored. This code should be treated as urgent because of this.

Symptoms of a P0704 code may include:

• Intermittent or failed engine starting
• Reduced fuel efficiency
• Excessive engine idle speed
• The traction control system may be disabled
• Safety functions may be disabled on some models

Possible causes for this code being set are:

• Faulty clutch switch
• Worn clutch pedal lever or clutch pedal pivot ring
• Shorted or open wiring and/or connectors in the clutch switch circuit
• Blown fuse or burned fuse link
• PCM programming error or faulty PCM

Diagnostic and Repair Procedures

A scan tool, a digital volt/ohmmeter, and a service manual (or All Data DIY) for your vehicle are all the tools that will be needed to diagnose a P0704 code.

A visual inspection of the clutch switch circuit wiring is a good place to start your diagnosis. Test all system fuses and replace blown fuses as needed. Test the battery load, check battery cables and battery ground cables at this point. Also check the alternator output.

Locate the diagnostic connector, connect the scan tool, and retrieve all stored codes and freeze frame data. Note this information, as it may be helpful for further diagnosis. Clear the codes and test drive the vehicle to see if the code resets immediately.

If it does: Use the DVOM to check battery voltage at the clutch switch input circuit. Some vehicles are equipped with multiple clutch switches to accommodate multiple functions. Consult All Data DIY to determine your clutch switch configuration. If the input circuit has battery voltage, press the clutch pedal and check for battery voltage on the output circuit. If there is no voltage on the output circuit, suspect a faulty or misadjusted clutch switch. Also ensure the clutch pivot lever and pedal arm are mechanically sound. Check for play in the clutch pedal pivot ring.

If there is voltage on both sides of the clutch switch (when the pedal is pressed), check the clutch switch input circuit at the PCM. This could be a battery voltage signal or a reference voltage signal; consult your vehicle manufacturer’s specifications. If there is an input signal to the PCM, suspect a faulty PCM or a PCM programming error.

If there is no clutch switch input signal at the PCM connector, disconnect all associated controllers and use the DVOM to test the resistance of all circuits in the system. Repair or replace any shorted or open circuits (between the clutch switch and the PCM) as necessary.

Additional Diagnostic Notes:

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Check system fuses with the clutch pedal pressed. Fuses that may appear normal during initial testing may fail when the circuit is placed under load.
Often, a worn clutch pivot arm or clutch pedal pivot ring can be misdiagnosed as a faulty clutch switch.

Understanding the Mercury P1442 Diagnostic Trouble Code

The P1442 code is an OBD-II diagnostic trouble code specific to Mercury vehicles that indicates a malfunction in the Evaporative Emission Control (EVAP) system’s vent control circuit. This system is crucial for preventing fuel vapors from escaping into the atmosphere, making the P1442 code both an emissions compliance issue and a potential drivability concern. When this code appears, your vehicle’s powertrain control module (PCM) has detected an electrical problem within the circuit that controls the EVAP canister vent solenoid.

What is the EVAP System and How Does It Work?

The Evaporative Emission Control system is designed to capture and store fuel vapors from the fuel tank, preventing them from being released into the atmosphere. The system consists of several key components:

• Fuel tank and cap
• Charcoal canister
• Vent control valve/solenoid
• Purge control valve/solenoid
• Various hoses and connectors

When the engine is off, fuel vapors are absorbed by the charcoal canister. During engine operation, the PCM opens the purge valve, allowing stored vapors to be drawn into the intake manifold and burned during combustion. The vent control valve, which is the component associated with P1442, regulates fresh air flow into the system and seals the system during leak tests.

Technical Specifications of P1442 Code

The P1442 code is manufacturer-specific, meaning its exact definition can vary between different Mercury models. However, the general interpretation remains consistent across most applications:

• Code Type: Manufacturer Specific (Mercury/Ford)
• ICD Definition: EVAP System Vent Control Circuit Malfunction
• System Affected: Evaporative Emissions Control
• Severity: Moderate – Can affect fuel economy and emissions compliance
• Drivability: Usually minimal immediate impact on performance

Common Symptoms and Causes of P1442 in Mercury Vehicles

Recognizing the symptoms and understanding the potential causes of P1442 is essential for accurate diagnosis and repair. While this code doesn’t typically cause severe drivability issues, it can lead to failed emissions tests and reduced fuel efficiency over time.

Primary Symptoms of P1442 Code

When the P1442 code is stored in your Mercury’s PCM, you may notice several indicators:

• Illuminated Check Engine Light (MIL)
• Possible failed emissions test
• Reduced fuel economy in some cases
• Fuel odor near the vehicle (if vent valve is stuck open)
• Difficulty refueling (if vent valve is stuck closed)
• No noticeable drivability issues in most instances

Root Causes of P1442 Diagnostic Trouble Code

The P1442 code can be triggered by various issues within the EVAP vent control circuit. Understanding these potential causes will streamline your diagnostic process:

• Faulty EVAP Canister Vent Solenoid: The most common cause, where the solenoid fails electrically or mechanically
• Damaged Wiring or Connectors: Corroded, broken, or shorted wires in the vent control circuit
• Poor Electrical Connections: Loose or corroded connectors at the vent solenoid or PCM
• Blown Fuse: A fuse specifically protecting the EVAP system circuits
• Failed PCM: Rare, but possible if all other components test correctly
• Blocked or Pinched Vent Hose: Physical obstruction preventing proper vent operation

Professional Diagnostic Procedure for P1442 Code

Proper diagnosis of P1442 requires a systematic approach using appropriate tools and following manufacturer-recommended procedures. This section outlines a comprehensive diagnostic strategy that technicians use to identify the root cause efficiently.

Required Tools and Safety Precautions

Before beginning diagnosis, ensure you have the proper equipment and observe necessary safety measures:

• Digital Multimeter (DMM) with resistance and voltage testing capabilities
• Quality OBD-II scanner capable of reading manufacturer-specific codes
• Vehicle service manual or repair database for wiring diagrams
• Smoke machine for EVAP system leak testing (professional applications)
• Safety glasses and gloves
• Well-ventilated work area
• Fire extinguisher nearby when working with fuel system components

Step-by-Step Diagnostic Process

Follow this systematic approach to diagnose P1442 accurately:

• Step 1: Verify the code with an OBD-II scanner and check for additional codes
• Step 2: Perform visual inspection of EVAP system components, wiring, and connectors
• Step 3: Check the vent solenoid electrical connector for corrosion or damage
• Step 4: Test vent solenoid resistance and compare to specifications (typically 20-40 ohms)
• Step 5: Check for power and ground at the vent solenoid connector with ignition on
• Step 6: Test wiring continuity between the vent solenoid and PCM
• Step 7: Perform functional test of the vent solenoid using a scan tool bidirectional controls
• Step 8: Inspect vent hoses for restrictions, damage, or improper routing

Repair Procedures and Prevention Strategies

Once the root cause of P1442 has been identified through proper diagnosis, appropriate repairs can be performed. This section covers common repair procedures and how to prevent recurrence of this issue.

Common Repair Solutions for P1442

Depending on the diagnostic findings, one or more of these repairs may be necessary:

• Replacing EVAP Vent Solenoid: The most common repair when the solenoid tests faulty
• Repairing Wiring Harness: Addressing damaged wires with proper splicing techniques
• Cleaning or Replacing Connectors: Addressing corrosion issues in electrical connections
• Replacing Fuses: If a blown fuse is identified as the cause
• Clearing Vent Pathways: Removing obstructions from vent hoses or tubes
• PCM Replacement/Reprogramming: Rarely needed, only after eliminating all other possibilities

Preventive Maintenance and Long-Term Solutions

Preventing recurrence of P1442 and similar EVAP system codes involves regular maintenance and awareness:

• Regularly inspect EVAP system components during routine maintenance
• Keep the area around the EVAP canister and vent solenoid clean and free of debris
• Address any fuel system issues promptly to prevent additional strain on EVAP components
• Always use a quality fuel cap that seals properly
• Have emissions system checked annually, especially before required testing
• Address any check engine lights immediately to prevent additional system damage

Technical Considerations and Professional Insights

Successfully addressing P1442 requires understanding some technical nuances specific to Mercury vehicles and the EVAP system operation.

Vehicle-Specific Considerations for Mercury Models

Different Mercury models may have variations in their EVAP system design that affect diagnosis:

• Mercury Sable/Taurus: Vent solenoid typically located near fuel tank
• Mercury Grand Marquis: Often has more accessible EVAP components
• Mercury Mountaineer: Higher ground clearance may affect component location
• Model Year Variations: Earlier models may have different testing procedures
• Engine Specifics: Different engines may have unique routing of EVAP components

When to Seek Professional Assistance

While some DIY enthusiasts can address P1442, certain situations warrant professional help:

• If you lack proper diagnostic tools or technical expertise
• When the root cause isn’t apparent after basic testing
• If multiple EVAP codes are present simultaneously
• When the vehicle is still under warranty
• If you suspect PCM issues or complex electrical problems
• When emissions testing deadlines are approaching

Successfully diagnosing and repairing P1442 requires patience, proper tools, and methodical troubleshooting. By following the procedures outlined in this guide, you can effectively address this EVAP system issue in your Mercury vehicle, restore proper emissions control function, and extinguish that check engine light with confidence.

Understanding Mazda Diagnostic Trouble Code P1442

When your Mazda’s check engine light illuminates and you retrieve diagnostic trouble code P1442, you’re dealing with a specific issue within the Evaporative Emission Control (EVAP) system. This code indicates a malfunction in the Leak Detection Pump (LDP) Control Circuit, a critical component responsible for monitoring and maintaining the integrity of your vehicle’s fuel vapor containment system. The EVAP system prevents gasoline vapors from escaping into the atmosphere, and the leak detection pump is its primary diagnostic tool.

What is the EVAP System and Why It Matters

The Evaporative Emission Control system is a sealed network designed to capture and store fuel vapors from the fuel tank, preventing their release into the environment. This system includes several key components:

• Fuel tank and cap
• Charcoal canister (vapor storage)
• Purge valve/solenoid
• Vent valve
• Leak Detection Pump (LDP)
• Various hoses and connectors

Modern vehicles like Mazdas use sophisticated monitoring systems to ensure the EVAP system remains leak-free, which is where the leak detection pump plays a crucial role.

The Role of the Leak Detection Pump in Mazda Vehicles

The Leak Detection Pump is an electrically-operated pump that creates vacuum or pressure within the EVAP system to test for leaks. When the vehicle’s computer (PCM) initiates a self-test, it activates the LDP to pressurize the system. The PCM then monitors the system’s ability to hold pressure. If the control circuit for this pump malfunctions, the PCM cannot perform this critical test and will set code P1442.

Common Symptoms of Mazda P1442 Code

Recognizing the symptoms associated with code P1442 can help you address the issue promptly. While some vehicles may show no drivability concerns, others may exhibit noticeable signs that warrant immediate attention.

Illuminated Check Engine Light

The most common and obvious symptom is the illumination of the check engine light on your dashboard. This warning indicates the Powertrain Control Module (PCM) has detected a fault in the LDP control circuit and stored code P1442 in its memory.

Failed Emissions Testing

Since the EVAP system is part of your vehicle’s emissions control system, an active P1442 code will typically cause your Mazda to fail state emissions inspections. This can prevent you from renewing your vehicle registration until the issue is resolved.

Potential Fuel Odor

While not always present with P1442, you might notice a faint gasoline smell around your vehicle if the EVAP system isn’t functioning correctly. This occurs when fuel vapors aren’t being properly contained and processed through the system.

No noticeable drivability issues

Many Mazda owners report no change in vehicle performance, fuel economy, or driving characteristics when P1442 is present. The system primarily affects emissions rather than engine operation, which can make the code easy to ignore—though not recommended.

Primary Causes of P1442 in Mazda Vehicles

Several issues can trigger the P1442 diagnostic trouble code in Mazda models. Understanding these potential causes will help you diagnose the problem efficiently and accurately.

Faulty Leak Detection Pump

The most direct cause of P1442 is a malfunctioning leak detection pump itself. The LDP contains electrical components, valves, and a diaphragm that can fail over time. Common pump failures include:

• Electrical motor failure
• Stuck or seized pump mechanism
• Internal diaphragm damage
• Corrosion or water intrusion

Electrical Circuit Problems

Since P1442 specifically references the “control circuit,” wiring issues are a frequent culprit. These can include:

• Damaged or frayed wiring to the LDP
• Corroded or loose electrical connectors
• Blown fuses affecting the LDP circuit
• Poor ground connections
• Short circuits or open circuits in the control wiring

PCM Software Issues

In some Mazda models, outdated PCM programming can cause false P1442 codes. Mazda has issued Technical Service Bulletins (TSBs) for certain vehicles addressing EVAP system diagnostic improvements through PCM reprogramming.

Step-by-Step Diagnostic Procedure for P1442

Proper diagnosis of P1442 requires a systematic approach to identify the root cause efficiently. Follow these steps to pinpoint the issue accurately.

Initial Visual Inspection

Begin with a thorough visual examination of the EVAP system components:

• Locate the leak detection pump (typically near the fuel tank or in the engine bay)
• Check all electrical connections for corrosion, damage, or looseness
• Inspect wiring harness for chafing, cuts, or burn marks
• Verify the integrity of vacuum hoses connected to the LDP
• Check relevant fuses in the engine compartment and interior fuse boxes

Electrical Circuit Testing

Using a digital multimeter, perform these electrical tests:

• Check for battery voltage at the LDP power supply wire with ignition ON
• Verify ground circuit integrity
• Test control signal from PCM using a NOID light or oscilloscope
• Measure circuit resistance for opens or shorts
• Compare readings against manufacturer specifications

Leak Detection Pump Functional Testing

If electrical circuits test normal, proceed to functional testing of the LDP:

• Command the LDP using a professional scan tool
• Listen for pump activation sounds
• Test pump resistance against factory specifications
• Check for proper vacuum/pressure generation
• Perform mechanical operation tests if applicable

Repair Procedures and Cost Considerations

Once you’ve identified the root cause of P1442, you can proceed with the appropriate repair strategy.

Leak Detection Pump Replacement

Replacing a faulty LDP is typically straightforward:

• Disconnect the negative battery cable for safety
• Locate and disconnect electrical connector from old LDP
• Remove vacuum hoses, noting their positions for reassembly
• Unbolt mounting hardware and remove the pump
• Install new pump, reconnect all hoses and electrical connections
• Clear codes and perform readiness monitor drive cycle

Wiring Repair Techniques

For circuit issues, proper repair is essential:

• Repair damaged wires using solder and heat shrink tubing
• Replace damaged connectors with OEM-quality parts
• Ensure proper strain relief and routing of repaired wiring
• Protect repairs from moisture and heat exposure
• Test circuit operation before reassembly

Cost Estimation for P1442 Repairs

Repair costs for P1442 vary significantly based on the cause:

• Leak Detection Pump replacement: $150-$400 (parts) + 1-2 hours labor
• Wiring repair: $100-$300 (typically 1-2 hours labor)
• PCM reprogramming: $100-$200 at dealership
• Diagnostic time: 0.5-1.5 hours typically charged

Prevention and Maintenance Tips

While some causes of P1442 are unavoidable, proper maintenance can reduce the likelihood of recurrence.

Regular EVAP System Inspection

Include EVAP system components in your routine maintenance checks:

• Visually inspect LDP and connections during oil changes
• Check for cracked or brittle vacuum hoses
• Ensure fuel cap is properly tightened after refueling
• Address any check engine lights promptly

Proper Electrical Connection Maintenance

Protect electrical components from moisture and corrosion:

• Apply dielectric grease to electrical connectors
• Ensure wiring harnesses are properly secured
• Address any rodent infestation issues promptly
• Avoid pressure washing engine compartment directly at electrical components

Code P1442 in your Mazda, while not typically causing immediate drivability issues, should be addressed promptly to maintain emissions compliance and prevent potential future problems. With proper diagnosis and repair, this issue can be resolved effectively, restoring your vehicle’s EVAP system to proper operation.

What Does It Mean?

This generic powertrain diagnostic trouble code (DTC) generally applies to OBD-II equipped vehicles that have a transmission fluid level sensor. Vehicle makes may include, but are not limited to, GM, Chevrolet, Ford, Dodge, Ram, Toyota, Hyundai, etc. This code is rare.

The Transmission Fluid Level (TFL) sensor is used to illuminate a warning light on the dashboard in case of low fluid level.

When the fluid level is within an acceptable range, the switch is grounded. When the transmission fluid drops below a predetermined level, the switch opens and a “low transmission fluid level” warning appears on the dashboard.

TFL sensors receive a reference voltage from the PCM. The PCM monitors the circuit and when it recognizes that the switch has opened, it activates the low fluid level warning on the instrument cluster.

Code P070A is set when the PCM detects a malfunction in the transmission fluid level sensor circuit. Related codes include P070B, P070C, P070D, P070E, and P070F.

Code Severity and Symptoms
The severity of this transmission code is moderate to severe. In some cases, this code and related codes may indicate a low transmission fluid level which, if left unaddressed, can damage the transmission. It is a good idea to address this code as soon as possible.

Symptoms of a P070A trouble code may include:

Low transmission fluid warning light illuminated
Check engine light
Transmission performance issues
Common causes of this DTC code

Causes

Possible causes of this code may include:

Faulty transmission fluid level sensor
Low transmission fluid level
Wiring problems
Faulty PCM
Diagnostic and repair procedures
Start by checking the transmission fluid level and condition according to the manufacturer’s recommendations. Then, inspect the transmission fluid level sensor and its corresponding wiring. Look for loose connections, damaged wiring, etc. If damage is detected, repair as necessary, clear the code, and see if it returns. Next, check for Technical Service Bulletins (TSBs) related to the issue. If nothing is found, you will need to proceed with step-by-step diagnosis of the system.

The following is a generalized procedure, as tests for this code vary by vehicle. To accurately test the system, you will need to refer to the manufacturer’s diagnostic flowchart.

Check the wiring
Before continuing, you will want to consult factory wiring diagrams to determine which wires are which. Autozone offers free online repair manuals for many vehicles, and ALLDATA offers single-vehicle subscriptions.

Check the reference voltage side of the circuit
Ignition on, use a digital multimeter set to DC volts to check the reference voltage (usually 5 or 12 volts) from the PCM. To do this, connect the negative meter lead to ground and the positive meter lead to the sensor B+ terminal on the harness side of the connector. If no reference signal is present, set the meter to ohms (ignition off) between the reference voltage pin on the TFL and the reference voltage pin on the PCM. If the meter reads out of limits (OL), there is an open circuit between the PCM and the sensor that will need to be located and repaired. If the meter reads a numerical value, there is continuity.

If everything is okay up to this point, you will want to verify that the PCM is powered. To do this, turn the ignition on and set the meter to DC volts. Connect the positive multimeter lead to the PCM’s reference voltage terminal and the negative lead to ground. If there is no reference voltage from the PCM, the PCM is likely faulty. However, PCMs rarely fail, so it is a good idea to double-check your work up to this point.

Check the ground side of the circuit
Ignition off, use a digital multimeter set to ohms to check for continuity. Connect the meter between the transmission fluid level sensor’s ground terminal and chassis ground. If the meter reads a numerical value, there is continuity. If the meter reads out of limits (OL), there is an open circuit between the PCM and the sensor that will need to be located and repaired.

Check the sensor
If everything checks out at this point, the sensor is likely faulty. To check this, turn the ignition off and set your multimeter to read ohms. Remove the connector from the transmission fluid level sensor and connect the meter to the sensor’s terminals. If the meter reads out of limits (OL), the sensor is open internally and must be replaced.

What Does It Mean?

This generic powertrain diagnostic trouble code (DTC) generally applies to OBD-II equipped vehicles that have a transmission fluid level sensor. Vehicle makes may include, but are not limited to, GM, Chevrolet, Ford, Dodge, Ram, Toyota, Hyundai, etc. This code is rare.

The Transmission Fluid Level (TFL) sensor is used to illuminate a warning light on the dashboard in case of low fluid level.

When the fluid level is within an acceptable range, the switch is grounded. When the transmission fluid drops below a predetermined level, the switch opens and a “low transmission fluid level” warning appears on the dashboard.

TFL sensors receive a reference voltage from the PCM. The PCM monitors the circuit and when it recognizes that the switch has opened, it activates the low fluid level warning on the instrument cluster.

Code P070B is set when the PCM detects a malfunction in the range or performance of the transmission fluid level sensor. Related codes include P070A, P070C, P070D, P070E, and P070F.

Code Severity and Symptoms
The severity of this transmission code is moderate to severe. In some cases, this code and related codes may indicate a low transmission fluid level which, if left unaddressed, can damage the transmission. It is a good idea to address this code as soon as possible.

Symptoms of a P070B trouble code may include:

Low transmission fluid warning light illuminated
Check engine light illuminated
Transmission performance issues
Common causes of this DTC code

Causes

Possible causes of this code may include:

Faulty transmission fluid level sensor
Low transmission fluid level
Wiring problems
Faulty PCM
Diagnostic and Repair Procedures
Start by checking the transmission fluid level and condition according to the manufacturer’s recommendations. Then, inspect the transmission fluid level sensor and its corresponding wiring. Look for loose connections, damaged wiring, etc. If damage is detected, repair as necessary, clear the code, and see if it returns. Next, check for Technical Service Bulletins (TSBs) related to the issue. If nothing is found, you will need to proceed with step-by-step diagnosis of the system.

The following is a generalized procedure, as tests for this code vary by vehicle. To accurately test the system, you will need to refer to the manufacturer’s diagnostic flowchart.

Check the Wiring
Before continuing, you will want to consult the factory wiring diagrams to determine which wires are which. Autozone offers free online repair manuals for many vehicles and ALLDATA offers single-vehicle subscriptions.

Check the Reference Voltage Side of the Circuit
Ignition on, use a digital multimeter set to DC volts to check the reference voltage (usually 5 or 12 volts) from the PCM. To do this, connect the negative meter lead to ground and the positive meter lead to the sensor B+ terminal on the harness side of the connector. If no reference signal is present, set the meter to ohms (ignition off) between the reference voltage pin on the TFL and the reference voltage pin on the PCM. If the meter reads out of limits (OL), there is an open circuit between the PCM and the sensor that will need to be located and repaired. If the meter reads a numerical value, there is continuity.

If everything is okay up to this point, you will want to verify that the PCM is powered. To do this, turn the ignition on and set the meter to DC volts. Connect the positive multimeter lead to the PCM’s reference voltage terminal and the negative lead to ground. If there is no reference voltage from the PCM, the PCM is likely faulty. However, PCMs rarely fail, so it is a good idea to double-check your work up to this point.

Check the Ground Side of the Circuit
Ignition off, use a digital multimeter set to ohms to check for continuity. Connect the meter between the transmission fluid level sensor’s ground terminal and chassis ground. If the meter reads a numerical value, there is continuity. If the meter reads out of limits (OL), there is an open circuit between the PCM and the sensor that will need to be located and repaired.

Check the Sensor
If everything checks out at this point, the sensor is likely faulty. To check this, turn the ignition off and set your multimeter to read ohms. Remove the connector from the transmission fluid level sensor and connect the meter to the sensor’s terminals. If the meter reads out of limits (OL), the sensor is open internally and must be replaced.