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 Descriptor
This diagnostic procedure supports the following DTC:
DTC C0287 Delivered Torque Signal Malfunction
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 open or shorted 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. Refer to the following:
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 is present.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views and Powertrain Control Module Connector End Views for the 4.8L, 5.3L and 6.0L engine | ||||
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 |
3 | Is this vehicle equipped with vehicle stability enhancement system (VSES) (JL4)? | -- | Go to DTC C0244 | Go to Step 4 |
Does the voltage measure greater than the specified value? | 4.75 V | Go to Step 5 | Go to Step 6 | |
Does the voltage measure less than the specified value? | 0.15 V | Go to Step 7 | Go to Step 11 | |
6 | Test the delivered torque signal circuit for an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 9 |
7 |
Does the scan tool display a duty cycle of the delivered torque signal within the specified range? | 25-95% | Go to Step 8 | Go to Step 12 |
8 |
Does the frequency of the delivered torque signal measure within the specified range? | 121-134 Hz | Go to Step 10 | Go to Step 13 |
9 |
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 |
10 | Replace the EBCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
11 | 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 14 | Go to Step 13 |
12 | 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 14 | Go to Step 13 |
13 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
14 |
Does the DTC reset? | -- | Go to Step 3 | System OK |
