DTC P0500: No Vehicle Speed Sensor Signal: Testing

1. Turn ignition on, with engine off. Using scan tool, read DTCs. If DTC SPECIFIC GOOD TRIP counter is displayed and displayed count is "0", go to next step. If DTC SPECIFIC GOOD TRIP counter is not displayed or displayed count is not "0", go to step  7 .
2. Using scan tool, read DTCs. If any CAB module DTCs are present, see appropriate ANTI-LOCK article in BRAKES. If no CAB module DTCs are present, go to next step.
3. Turn ignition off. Disconnect CAB module connector. CAB module is located on front of Hydraulic Control Unit (HCU). HCU is mounted near brake master cylinder. Disconnect PCM connectors. PCM is located on firewall in right rear corner of engine compartment. Inspect connectors for damaged pins, corrosion and loose terminals. Repair connectors as necessary. If connectors are okay, measure resistance of White/Orange wire between terminals No. 27 at PCM C2 connector and No. 3 at CAB module connector. See Figure and Fig 1 . If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in White/Orange wire.
4. Reconnect PCM connectors. Ensure CAB module connector is still disconnected. Turn ignition on, with engine off. Measure voltage between ground and terminal No. 3 (White/Orange wire) at CAB module connector. 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 White/Orange wire.
5. Connect one end of a jumper wire to terminal No. 3 (White/Orange wire) at CAB module connector. Using scan tool, read VSS signal while briefly tapping 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.
6. At this time, PCM is assumed to be defective. Replace PCM.
7. Turn ignition off. Visually inspect related connectors and wiring harness for damage. Repair connectors and wiring harness as necessary. If connectors and wiring harness are okay, start engine and allow it to idle. With engine running, wiggle wiring harness from CAB to PCM. CAB module is located on front of Hydraulic Control Unit (HCU). HCU is mounted near brake master cylinder. PCM is located on firewall in right rear corner of engine compartment. Using scan tool, read DTCs. Using scan tool, read DTCs. If GOOD TRIP counter display count changes to "0", repair connector or wiring harness where wiggling caused display to change. If GOOD TRIP counter display count does not change to "0", no problem is indicated at this time. Check for any related technical service bulletins that may apply.

Fig 1: Identifying Controller Anti-Lock Brake Module Connector Terminals

Courtesy of DAIMLERCHRYSLER CORPORATION