Fix P0500: Mechanic’s solutions that WORKED

The P0500: Vehicle Speed Sensor Malfunction points to a fault in the vehicle’s speed sensor system, which can affect how the speedometer displays speed and impact transmission operations. This malfunction typically arises from issues with the vehicle speed sensor itself, its connections, or related systems that feed speed data to the car’s computer.

P0500 quick overview

Meaning	P0500: Vehicle Speed Sensor Malfunction
Is it serious?	This code can be serious as it may affect the vehicle’s speedometer function and transmission performance.
Possible causes	– Faulty or damaged vehicle speed sensor – Wiring issues, such as open circuits or shorts – Problems with the speedometer or related components – ECM/PCM configuration issues – Wheel speed sensor malfunctions affecting VSS signal
How to diagnose?	Inspect VSS: Check the vehicle speed sensor for damage or wear. Check Wiring and Connections: Examine wiring and connections related to the VSS and ECM/PCM. Verify Speedometer Operation: Ensure the speedometer is functioning correctly. Scan for Additional Codes: Use a diagnostic scanner to identify any other related codes. Evaluate ECM/PCM Configuration: Confirm that the ECM/PCM is correctly configured for the vehicle. Test Related Sensors: Check related components like wheel speed sensors if they contribute to vehicle speed data.

How to fix P0500 – learn from mechanics

I looked into P0500 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Dodge

Vehicle Information: 1998 Dodge Ram 1500 Laramie 5.9L CAB

Issue + Repair History:

• ABS, Brake, Check Engine Lights on, and no speedometer function.
• Initial diagnosis showed code PO500 (no vehicle speed sensor signal) and ABS code “ROM CHECKSUM, WATCHDOG”.
• Attempted clearing of codes, but code 72 reoccurred immediately.
• Considered replacing CAB following procedure for code 72.
• Issue started before the vehicle came in for a scheduled oil change.

Other OBD2 Codes + Test Results:

• ABS Codes: 72
• Engine and Transmission Codes: PO500

Suggestions to Fix Issue:

• Check and possibly replace the speed sensor in the rear differential.
• Use OEM parts for replacement.
• A shorted VSS sensor may cause the ABS computer to trigger code 72.

Final Fix:

• The issue was resolved by replacing the sensor in the rear differential. The community’s consensus pointed towards this being a common issue with this model.

Case #2: Subaru

Vehicle Information: 1995 Subaru Legacy L 2.2L

Issue + Repair History:

• Intermittent inoperative speedometer and MIL activation.
• Initially replaced VSS, which temporarily resolved the issue.
• Problem returned; rescanning showed code P0500.
• Connections to VSS and the computer were checked and found okay.

Computer Codes & Descriptions:

• P0500: No VSS Signal

Suggestions to Fix Issue:

• Check speedometer cluster for loose connections or cracked PC board joints.
• Test drive gear in the gearbox for mechanical issues.
• Consider the possibility of speedometer head problems.
• Check screws on the back of the speedometer head.
• Test the VSS for voltage generation when spun.

Final Fix:

• The issue was resolved by replacing the speedometer head. After replacement, no further problems with the speedometer were reported.

Case #3: Ford

Vehicle Information: 2003 Ford F-150 King Ranch 5.4L

Issue + Repair History:

• Whining noise in gear at idle and during driving in all gears, coming from the torque converter.
• Previous shop dropped the pan, found debris, and replaced the fluid.

Computer Codes & Descriptions:

• P0741: Torque Converter Clutch Circuit Performance or Stuck Off
• P0500: Vehicle Speed Sensor

Suggestions to Fix Issue:

• Check if the torque converter is engaging properly.
• Inspect the vehicle for a torque converter or pump stator bushing fault.
• Consider the possibility that a failing torque converter is throwing off the Vehicle Speed Sensor (VSS) and causing code P0500.
• Inspect the torque converter and front pump for mechanical failure or noise sources.
• Verify the transmission type (4R100 or 4R70W).
• Address the VSS code first as it may cause the P0741 code.
• Evaluate the need for a transmission overhaul.

Final Fix:

• The torque converter was identified as needing replacement and the transmission required rebuilding. Additionally, it was advised to replace the VSS and ensure electronic testing post-repair. The vehicle was sent to a transmission shop for these repairs.

Case #4: Hyundai

Vehicle Information: 2001 Hyundai Santa Fe GL 2.7L

Issue + Repair History:

• Initially replaced PCM due to a no-start issue.
• After PCM replacement, encountered code P0500 (VSS malfunction) even though speedometer worked.
• Replaced VSS but the issue returned; live data showed no VSS signal in PCM.
• Found discrepancies in wiring diagrams; uncertain about connector and pin details for VSS.
• Replaced right axle due to a cracked exciter ring and replaced the sensor.
• Encountered new code: 1529 (TCU request CE light) and P0500 in TCU.

Computer Codes & Descriptions:

• P0500: VSS Malfunction
• 1529: TCU Request CE Light

Suggestions to Fix Issue:

• Check right front wheel speed sensor as it provides VSS signal to PCM.
• Consider the possibility of issues with the ABS system or connections.
• Verify the role of different sensors for speed signal (wheel speed sensor, transmission sensor).
• Suggestion to reprogram the TCM if necessary.
• Clear codes from both ECM and TCM.

Final Fix:

• Issue was related to using ECMs from vehicles with ABS, while the subject vehicle did not have ABS.
• Received a VSS signal with the original ECM when the vehicle was pushed, indicating the issue was with the replacement ECMs.
• Vehicle was driven with the check engine light on, waiting for further information from the recycler and dealer.

Case #5: Kia

Vehicle Information: 2001 Kia Optima LX 2.5L

Issue + Repair History:

• Experiencing issues with the Vehicle Speed Sensor (VSS) data not matching ECM readings.
• Alldata electrical wiring diagram did not match the vehicle’s actual wiring.
• Speedometer worked normally but transmission and engine data showed 0 VMH during road tests.
• VSS showed good waveform on MODIS graph at VSS and DLC.

Computer Codes & Descriptions:

• P0500: Vehicle Speed Sensor Malfunction

Suggestions to Fix Issue:

• Check for open or short in white wire between instrument cluster and ECM.
• Inspect for open or short in wire between VSS and ignition switch, and in brown wire between VSS and ECM.
• Consider the possibility of speedometer, tachometer, or VSS malfunction.
• Verify the right front wheel speed sensor signal used by the PCM.
• Utilize Kiatechinfo.com for accurate factory information.

Final Fix:

• The car was sent to the dealer where the ECM was reconfigured, resolving the issue.

Common Advice	Brief Description of Diagnostic Step
Check and Verify Wiring and Connections	Inspect the wiring and connections related to the VSS and ECM for any open circuits, shorts, or loose connections.
Inspect the Vehicle Speed Sensor (VSS)	Test the VSS for proper operation and signal output, including waveform analysis with a scan tool.
Evaluate Speedometer Function	Verify if the speedometer is working correctly, as its malfunction can sometimes trigger the P0500 code.
Consider Related Sensors and Inputs	Check related sensors, like wheel speed sensors, that might affect the VSS signal, particularly in vehicles where the ECM uses these inputs for speed data.
Look for Physical Damage to Sensor or Exciter Rings	Inspect the VSS and related components like exciter rings for any physical damage or wear.
Confirm Correct ECM Configuration or Reprogramming	Ensure the ECM is correctly configured for the vehicle, and consider reprogramming if necessary.
Utilize Accurate and Model-Specific Wiring Diagrams	Refer to model-specific wiring diagrams for accurate troubleshooting, considering discrepancies in repair manuals or databases.