P1644

DTC C0287, P1644, or P1689

Circuit Description
The EBCM supplies 5 VDC to the Powertrain Control Module (PCM) on the delivered torque signal circuit. The PCM toggles this voltage to ground in order to create the delivered torque signal at the EBCM. A signal with a frequency of 128 Hz 5 percent and a duty cycle of 25-95 percent is a valid delivered torque signal. The percentage of duty cycle is proportionate to the percentage of delivered torque.

DTC Descriptors
This diagnostic procedure supports the following DTCs:
^ DTC C0287 Delivered Torque Signal Malfunction
^ DTC P1644 Traction Control Delivered Torque Output Circuit
^ DTC P1689 Traction Control Delivered Torque Output Circuit

Conditions for Running the DTC
^ The ignition is ON.
^ The engine is running at a speed greater than 450 RPM for 1 second.

Conditions for Setting the DTC
C0287
The EBCM receives an invalid delivered torque signal for 300 milliseconds.

P1689
The PCM detects the delivered torque signal voltage as being less than 4.75 volts or greater than 5.25 volts.

Action Taken When the DTC Sets
^ The EBCM disables the TCS.
^ The traction off indicator turns ON.

Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for voltage supplied to the PCM from the EBCM.
9. The PCM may be damaged if the delivered torque signal circuit is shorted to voltage.