Test Procedure
- DF1 DIAGNOSTIC TROUBLE CODE (DTC) P0500 AND P1501
Are any DTCs present?
Yes No For any ABS module DTC, REFER to the appropriate, Anti-Lock Control to continue diagnostics.
For DTCs P0500 and P1501, GO to DF2.
For all others, DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . - DF2 CHECK THE PCM VEHICLE SPEED SIGNAL INPUT
- Access the PCM and monitor the VSS PID.
- Road test the vehicle while monitoring the VSS PID.
Does the VSS PID increase as the vehicle speed is increased and decrease as the vehicle speed is decreased?
Yes No Unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. REFER to NO DTCS PRESENT SYMPTOM CHART INDEX , if a driveability concern exists. GO to DF3. - DF3 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
Is the concern still present?
Yes No INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.