C0241

DTC C0241 or P0856

Circuit Description

The powertrain control module (PCM) supplies approximately 5 volts through an internal resistor to the electronic brake control module (EBCM) on the requested torque signal circuit. The EBCM toggles this voltage to ground in order to create the requested torque signal at the PCM. A signal with a frequency of 128 Hz +/- 5 percent and a duty cycle of 25-95 percent is a valid requested torque signal. The percentage of duty cycle is proportionate to the percentage of requested engine torque.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0241 or DTC P0856 Pulse Width Modulated (PWM) Requested Torque

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

C0241

The EBCM receives an invalid requested torque signal for 300 milliseconds.

P0856

The PCM detects open or shorted requested 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 vehicle stability enhancement system (VSES).
^ The stability 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. Refer to the following:

^ Testing for Electrical Intermittents Component Tests and General Diagnostics
^ Testing for Intermittent Conditions and Poor Connections Component Tests and General Diagnostics
^ Wiring Repairs
^ Connector Repairs

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.
4. This step tests for a shorted resistor in the EBCM or a short to voltage within the circuit, by verifying that a large voltage drop occurs in the circuit when the test lamp is placed in parallel with the DMM. The PCM may be damaged if either of these conditions is present.

Step 1 - Step 6:

Step 7 - Step 12: