Circuit Description
The EBCM Diagnostic System Check is an organized approach to identify problems associated with the Anti Lock Brake System. The EBCM 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 tests 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 intermittent problems. When an intermittent 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 Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Install a scan tool. Does the scan tool power up? | -- | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |
2 |
Does the scan tool communicate with the PCM and BCM control modules? | -- | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |
3 | Select the ABS and BCM display DTC function on the scan tool. Does the scan tool display any DTCs? | -- | Go to Symptoms | |
4 | Does the scan tool display any DTCs which begin with the letter "U"? | -- | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | Go to Diagnostic Trouble Code (DTC) List/Type for the Applicable DTC |
