Circuit Description
The electronic brake control module (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 Delivered Torque 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 500 RPM for 1 second. |
Conditions for Setting the DTC
C0287
The EBCM receives an invalid delivered torque signal for 300 milliseconds.
P1644 or 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
If equipped, the following actions occur:
| • | The EBCM disables the traction control system (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. Refer to Testing for Electrical Intermittents , Testing for Intermittent Conditions and Poor Connections , Wiring Repairs , and Connector Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for voltage supplied to the PCM from the EBCM.
-
The PCM may be damaged if the delivered torque signal circuit is shorted to voltage.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics in Engine Controls - 6.0L | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the DTC set? | -- | Go to Step 3 | Go to Diagnostic Aids |
Does the voltage measure within the specified range? | 4.75-5.25 V | Go to Step 5 | Go to Step 4 | |
4 | Test the delivered torque signal circuit for an open, a short to voltage, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 7 |
5 |
Does the scan tool display the duty cycle of the delivered torque signal is within the specified range? | 25-95% | Go to Step 6 | Go to Step 9 |
6 |
Does the frequency of the delivered torque signal measure within the specified range? | 121-134 Hz | Go to Step 7 | Go to Step 9 |
7 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 8 |
8 | Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | -- |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 | |
10 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 |
11 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 3 | System OK |
