Circuit Description
The electronic brake control module (EBCM) and the powertrain control module (PCM) simultaneously control the traction control system (TCS). The PCM sends a Delivered Torque message via a pulse width modulated (PWM) signal to the EBCM. The duty cycle of the signal is used to determine how much engine torque the PCM is delivering. Normal values are between 10 and 90 percent duty cycle. The EBCM supplies the pull up voltage that the PCM switches to ground to create the signal.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC C0244 Pulse Width Modulated (PWM) Delivered Torque |
| • | DTC P1689 Traction Control Delivered Torque Output Circuit |
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
C0244
The EBCM has detected an open, short to power or short to ground on the delivered torque signal circuit.
P1689
One of the following conditions exists:
| • | The PCM detects that delivered torque signal is out of the valid range. |
| • | The PCM does not receive the delivered torque signal. |
Action Taken When the DTC Sets
When the DTC sets the TCS cannot reduce engine torque, however the brake intervention portion of the TCS system remains operational.
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and you used the scan tool Clear DTC function. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
| • | The PCM automatically clears the history DTC when a current DTC is not detected in 40 consecutive warm-up cycles. |
Diagnostic Aids
Check for poor or intermittent connections of the EBCM and the PCM. Refer to Testing for Intermittent Conditions and Poor Connections .
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.
-
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 are present.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the DTC set? | -- | Go to Step 3 | Go to Diagnostic Aids |
Does the voltage measure greater than the specified value? | 10 V | Go to Step 4 | Go to Step 5 | |
Does the voltage measure less than the specified value? | 0.15 V | Go to Step 6 | Go to Step 8 | |
5 | Test the delivered torque signal circuit for an open or a short to ground. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9 |
6 | Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 7 |
7 | Replace the EBCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
8 | Test the delivered torque signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 |
9 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 |
10 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Does the DTC reset? | -- | Go to Step 3 | System OK |
