Circuit Description
The EBCM/EBTCM Diagnostic System Check is an organized approach to identify problems associated with the EBCM/EBTCM. This check must be the starting point for any EBCM/EBTCM complaint, and will direct you to the next logical step in diagnosing the complaint. The EBCM/EBTCM is a very reliable component and is not likely the cause of the malfunction. Most system complaints are linked to faulty wiring, connectors, and occasionally to components. Understanding the ABS system and using the tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.
Diagnostic Aids
| • | An intermittent failure in the electronic system may be very difficult to detect and to accurately diagnose. The EBCM/EBTCM test for different malfunctions under different vehicle conditions. For this reason, a thorough test drive is often needed in order to repeat a malfunction. If the system malfunction is not repeated during the test drive, a good description of the complaint may be very useful in locating an intermittent malfunction. Faulty electrical connections or wiring causes most intermitting problems. When an intermitting condition is suspected, check the suspected circuits for the following conditions: |
| - | Poor mating of connector halves or backed out terminals |
| - | Improperly formed or damaged terminals |
| - | Wire chafing |
| - | Poor wire to terminal connections |
| - | Dirty or corroded terminals |
| - | Damage to connector bodies |
| • | If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. Perform a thorough inspection of all related wiring and connectors pertaining to the history DTC stored. Refer to Intermittents and Poor Connections Diagnosis in wiring system. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Does the Scan Tool communicate with the EBCM/EBTCM? | -- | ||
2 | Does the scan tool communicate with other modules on the class 2 line? | -- | Go to No Communication with Electronic Brake Control Module/Electronic Brake and Traction Control Module | Go to Data Link Communications System Check in Data Link Communicatios |
3 |
Are there any current Diagnostic Trouble Codes? | -- | Go to Applicable DTC Table. Refer to Diagnostic Trouble Code (DTC) List | |
4 | Cycle the ignition switch from the OFF to ON position. Does the ABS Indicator come On then go Off after several seconds? | -- | ||
5 | Does the ABS Indicator come On and stay On? | -- | Go to ABS Indicator Always On | |
6 | Cycle the ignition switch from the OFF to ON position. Does the Traction Off Indicator (car icon) come On then go Off after several seconds? | -- | ||
7 | Does the TCS Off Indicator or ASR Off Indicator come On and stay On? | -- | Go to Traction Control System Off Indicator Always On Or Go to | Or Go to Traction Control System Off Indicator Inoperative Or Go to |
8 | Cycle the ignition switch from the OFF to ON position. Does the LOW TRAC Indicator come on then go off after several seconds? | -- | ||
9 | Does the LOW TRAC Indicator come on and stay on? | -- | ||
10 | Are there any history DTCs? | -- | System OK | |
11 |
Did the history DTC set as a current DTC while the vehicle was being driven? | -- | Go to Applicable DTC Table. Refer to Diagnostic Trouble Code (DTC) List | System OK |
