C0055
DTC C0055 or P0609
Circuit Description
The powertrain control module (PCM) converts the signal from the vehicle speed sensor (VSS) to a 128k pulses/mile signal. The electronic brake control module (EBCM) uses the vehicle speed signal from the PCM to calculate the rear wheel speed.
DTC Descriptors
This diagnostic procedure supports the following DTC's:
^ DTC C0055 Rear Wheel Speed Sensor (Both Wheels) Circuit
^ DTC P0609 Rear Wheel Speed Sensor (Both Wheels) Circuit
Conditions for Running the DTC
C0055
Conditions for running as usual
^ The ignition is ON.
^ The vehicle speed is greater than 13 km/h (8 mph).
P0609
Conditions for running as usual
^ The ignition is ON.
^ The vehicle is not moving.
Conditions for Setting the DTC
C0055
Any of the following occurrences may cause the DTC to set:
^ The EBCM detects an open or shorted vehicle speed signal circuit for 500 milliseconds.
^ The EBCM detects the absence of the vehicle speed signal for 5 seconds. If more than one absent wheel speed sensor signal is detected, the condition must be present for 120 seconds to set DTC's.
^ The EBCM detects an erratic vehicle speed signal for 200 milliseconds.
P0609
The PCM detects low voltage on the vehicle speed signal circuit for 45 seconds.
Action Taken When the DTC Sets
^ The EBCM disables the ABS/dynamic rear proportion (DRP).
^ The ABS indicator turns ON.
^ The brake warning indicator turns ON.
^ An ECE 13 response may occur. Refer to ABS Description and Operation (W/JL4) ABS Description and Operation (W/O JL4) for a complete description of ECE 13.
Conditions for Clearing the DTC
The Conditions for Setting the DTC are no longer present and you use the scan tool Clear DTC's function.
Diagnostic Aids
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Intermittent Conditions and Poor Connections, Connector Repairs, Testing for Electrical Intermittents, and Wiring Repairs. Component Tests and General Diagnostics
Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for a voltage signal from the PCM.
4. This step tests for a missing or erratic vehicle speed signal from the PCM. An assistant may be required to perform this test.
