Circuit Description
The powertrain controlo module (PCM) supplies 5 volts on the desired torque circuit to the electronic brake and traction control module (EBTCM). The EBTCM toggles this 5 volt signal to a ground in order to produce a duty cycle signal. The signal is proportional to the amount of engine output torque reduction requested by the EBTCM. The EBTCM supplies this signal when it detects a wheel slip. In order to reduce engine output torque, the PCM reduces the amount of spark advance and in some cases, the PCM disables a number of fuel injectors. This diagnostic tests for a desired torque signal failure. If the PCM does not receive the desired torque signal, this diagnostic code (DTC) sets.
Conditions for Running the DTC
| • | The traction control has not failed. |
| • | The engine speed is more than 500 RPM for 20 seconds. |
Conditions for Setting the DTC
The desired torque signal is not received by the PCM for 3 seconds.
Action Taken When the DTC Sets
| • | The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL/DTC. |
Diagnostic Aids
Important:
• Remove any debris from the PCM connector surfaces before servicing
the PCM. Inspect the PCM connector gaskets when diagnosing or replacing
the module. Ensure that the gaskets are installed correctly. The
gaskets prevent contaminate intrusion into the PCM. • For any test that requires probing the PCM or a component
harness connector, use the J 35616
connector test adapter kit . Using this kit prevents damage
to the harness/component terminals. Refer to
Using Connector Test Adapters
in Wiring Systems. • Do not perform this diagnostic procedure if the customers concern
is not related to the antilock brake system (ABS) or the traction control
systems.
For an intermittent condition, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the EBTCM is receiving the 5 volts from the PCM. Use the connector test kit adaptor when probing the EBTCM connector.
-
If no DTCs are set, inspect connections at the EBTCM.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
|
Important: Perform this diagnostic procedure only if the customers concern is related to the ABS or the traction control systems. Refer to Diagnostic System Check in Antilock Brakes System.
Does the DMM display near the specified value? | 5 V | |||
|
Important: Verify communication between the scan tool and the EBTCM before you continue with this diagnostic. Refer to Diagnostic System Check in Antilock Brakes System. Are any antilock brake system (ABS), traction control system (TCS) or body control module (BCM) DTCs set? | -- | Go to Diagnostic System Check - Body Control System in Body Control Systems or Diagnostic System Check in Antilock Brake System | Go to Diagnostic Aids | |
4 | Probe the desired torque circuit at the EBTCM electrical connector with the DMM connected to ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the DMM display near the specified value? | B+ | ||
5 | Probe the desired torque circuit at the EBTCM electrical connector with a test lamp connected to B+. Is the test lamp illuminated? | -- | ||
6 |
Did you find and correct the condition? | -- | ||
7 | Repair the short to B+ on the desired torque circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
8 | Repair the short to ground on the desired torque circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
9 |
Did you find and correct the condition? | -- | ||
10 |
Important: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- | -- | |
11 |
Does the scan tool indicate that this test failed? | -- | ||
12 | Select the Capture Info option and the Review Info option with the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to applicable DTC | System OK |
