The EBCM/EBTCM and the PCM simultaneously control the traction control. The PCM receives a Requested Torque message via a pulse width modulated (PWM) signal from the EBCM/EBTCM requesting the desired torque level for proper TCS operation. The PCM supplies the pull up voltage.
The DTC sets if one of the following occur:
• | An open or short in the Requested Torque line between the EBCM/EBTCM and the PCM. |
• | A TCS communication malfunction detected by the PCM and indicated to the EBCM/EBTCM via a PWM message. |
• | A malfunction DTC is stored. |
• | The TCS is disabled. |
• | The TRACTION CONTROL indicator is turned ON. |
• | The ABS remains functional. |
• | The condition for the DTC is no longer present and you used the scan tool Clear DTC function. |
• | The EBCM/EBTCM does not detect the DTC in 50 drive cycles. |
• | It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. |
• | An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation. |
• | If an intermittent malfunction exists, refer to Intermittents and Poor Connections Diagnosis in Wiring Systems. |
• | The following conditions can cause this concern: |
- | An open in the Requested Torque circuit. |
- | An short to ground or voltage in the Requested Torque circuit. |
- | A wiring problem, terminal corrosion, or poor connection in the Requested Torque circuit. |
- | A communication frequency problem. |
- | A communication duty cycle problem. |
- | The EBCM/EBTCM is not receiving information from the PCM. |
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Was the ABS Diagnostic System Check performed? | -- | Go to Step 2 | |
2 | Inspect grounds G101 and ground G104. Ensure that each ground is clean, tight and free of damage. Were any loose, damaged or corroded grounds found? | -- | Go to Step 3 | Go to Step 4 |
3 | Repair the grounds as needed. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
Is the duty cycle within the specified range? | 85-95% | Go to Step 5 | Go to Step 6 | |
Using the J 39200 , measure the DC Hz between the J 39700 terminal 25 and terminal B. Is the frequency within the specified range? | 121-134 Hz | Go to Step 13 | Go to Step 7 | |
6 |
Is the voltage within the specified range? | 4.5-5.5 V | Go to Step 7 | Go to Step 8 |
7 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | -- | |
8 |
Is the voltage greater than the specified value? | 1.0 V | Go to Step 9 | Go to Step 10 |
9 | Repair the short to voltage in CKT 463. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | -- | |
10 |
Is the resistance equal to the specified value? | OL (infinite) | Go to Step 12 | Go to Step 11 |
11 | Repair the short to ground in CKT 463. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | -- | |
12 | Using the J 39200 DMM, measure the resistance between the J 39700 terminal 25 and the PCM connector C1 terminal 71. Is the resistance less than the specified value? | 2 ohms | Go to Step 13 | Go to Step 14 |
13 | Suspect the PCM. Refer to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 3.8L. Is the diagnosis complete? | -- | -- | |
14 | Repair the open in CKT 463. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | -- |