Circuit Description
Two-way serial communication is sent back and forth between the EBCM and the IPC. A message from the IPC is sent to the EBCM within seven seconds after ABS initialization. A serial communication failure does not allow the proper warning indicator commands to be sent back to the IPC.
Diagnostic Aids
The following conditions may cause an intermittent malfunction:
| • | A poor connection |
| • | Rubbed-through wire insulation |
| • | A broken wire inside the insulation |
The scan tool Serial Data Link (SDL) monitor used in this diagnostic is within the body portion of the scan tool. This requires exiting from the chassis portion of the scan tool to the main menu and entering into the body portion of the scan tool menu and selecting SDL MONITOR.
With the SDL monitor (ABS to IPC mode), any message that is being transmitted on the serial data link can be observed, refer to Instrument Cluster for further serial data link information.
Use the Lamp Test function of the Scan Tool in order to turn the indicator on while looking for an intermittent malfunction in the ABS warning indicator circuitry.
Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal-to-wiring connections |
| • | Physical damage to the wiring harness |
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
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Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual. | ||||||||
1 | Was the ABS Diagnostic System Check performed? | -- | ||||||
2 |
Did the amber ABS warning indicator turn on? | -- | ||||||
3 |
Did the amber ABS warning indicator flash? | -- | ||||||
4 | Inspect all of the connectors and the terminals for the following conditions:
Is there evidence of poor terminal contact or corrosion? | -- | ||||||
5 | Replace all of the terminals that exhibit signs of poor terminal contact or corrosion. Is the repair complete? | -- | -- | |||||
6 | Repair the instrument panel cluster. Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console. Is the repair complete? | -- | -- | |||||
7 | The malfunction is not present at this time. Refer to Diagnostic Aids for more information. Is the action complete? | -- | System OK | -- | ||||
