DTC P0500: No Vehicle Speed Sensor Signal: Testing
- Turn ignition on, engine off. Using scan tool, read DTCs. If GOOD TRIP counter is displayed for DTC P0500 and displayed count is "0", go to next step. If GOOD TRIP counter is not displayed for DTC P0500 and displayed count is not "0", go to step 8.
- Ensure ignition is on with engine off. Using scan tool, check CAB module for DTCs. See appropriate ANTI-LOCK article in BRAKES. If no CAB module DTCs exist, go to next step. If any CAB module DTCs exist, perform test procedures for CAB module DTCs.
- Ensure ignition is off. On 4.7L models, disconnect Transmission Control Module (TCM) connector. TCM is located next to PCM in right front of engine compartment. On all models, disconnect PCM connectors. PCM is located in engine compartment on passenger-side inner fender panel. Disconnect 14-pin CAB module connector. CAB module is located at driver's side rear corner of engine compartment, near brake booster. See Fig 2. Using DVOM, measure resistance of White/Orange wire (4.7L) or Dark Blue wire (5.9L) between CAB harness connector C1 terminal No. 12 and PCM harness connector C2 terminal No. 27. See Figure and Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in appropriate wire between CAB module and PCM.
- Ensure TCM and PCM connectors and 14-pin CAB module connector are still disconnected. Using DVOM, measure resistance between ground and PCM harness connector C2 terminal No. 27 (White/Orange wire on 4.7L or Dark Blue wire on 5.9L). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in appropriate wire between CAB module and PCM.
- Ensure ignition is off. Ensure TCM and PCM connectors and 14-pin CAB module connectors are still disconnected. Turn ignition on, engine off. Using DVOM, measure voltage of vehicle speed signal circuit between ground and CAB harness connector C1 terminal No. 12 (White/Orange wire). See Fig 1. If voltage is 6 volts or less, go to next step. If voltage is more than 6 volts, repair short to voltage in vehicle speed signal circuit between CAB module and PCM.
- Turn ignition off. Connect one end of jumper wire to CAB harness connector C1 terminal No. 12 (White/Orange wire). Turn ignition on, engine off. Using scan tool, monitor vehicle speed signal while quickly and momentarily touching other end of jumper wire to ground. If scan tool displays zero MPH, go to next step. If scan tool displays more than zero MPH, replace CAB module.
- At this time, PCM is assumed to be defective. Replace PCM.
- At this time, conditions for DTC to set do not exist or fault is an intermittent problem. Using scan tool, review FREEZE FRAME data. Attempt to duplicate condition that caused DTC to set. Visually inspect related connectors and wiring harness for damage. Check for any related Technical Service Bulletins (TSBs) that may apply. With engine running, wiggle wiring harness between CAB, PCM and/or TCM. If vehicle speed signal DTC returns while wiggling wiring harness, repair wiring harness where wiggling caused DTC to return. If vehicle speed signal DTC does not return while wiggling wiring harness, no problem is indicated at this time. Test is complete.
NOTE:
Models with 4-wheel anti-lock brakes have 2 connectors at CAB module. Connector C1 is a 14-pin connector and connector C2 is a 4-pin connector. Models with rear wheel anti-lock brakes have only one 14-pin connector at CAB module. See Fig 1.