Circuit Description
The ABS Diagnostic System Check is an organized approach to identifying problems associated with the ABS. This must be the starting point for any ABS related concern and will direct you to the next logical step in diagnosing a malfunction. Most system malfunctions are linked to faulty wiring, connections and occasionally, to components. Understanding the ABS system and using the diagnostic tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.
Test Description
The numbers below refer to the step numbers in the diagnostic table.
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Lack of communication may be due to partial or total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
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The presence of DTCs that begin with a "U" indicates that some other module is not communicating. The specified procedure will compile all of the available information before tests are performed. The electronic brake control module (EBCM) software does not support DTCs which begin with a "U". The EBCM may set DTC C0290, C0292 or C0297 to indicate a communication failure between the EBCM and the powertrain control module (PCM).
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These DTCs may be set by the PCM and may effect the rear wheel speed input to the EBCM or indicate an internal failure within the PCM.
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This DTC may be set by the instrument panel cluster (IPC) and effects the IPC's ability to illuminate indicators.
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These DTCs may be set by the suspension control module (RTD) and may effect VSES system operation. These DTCs do not effect ABS systems on vehicles which are not equipped with JL4.
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These DTCs may be set by the suspension control module (RTD) and may effect VSES system operation. These DTCs do not effect ABS systems on vehicles which are not equipped with JL4.
Step | Action | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Install a scan tool. Does the scan tool power up? | Go to Step 2 | Go to Scan Tool Does Not Power Up in Data Link Communications | ||||||||||
Does the scan tool communicate with all of the control modules listed above? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |||||||||||
3 | Use the scan tool in order to display DTCs for the following control modules:
Does the scan tool display any DTCs for the control modules listed above? | Go to Step 4 | |||||||||||
Does the scan tool display any DTCs that begin with a "U", DTC C0290, C0292 or C0297? | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | Go to Step 5 | |||||||||||
Does the scan tool display DTC P0500, P0502, P0503, P0562, P0563, P0601-P0607, P1381, P1621, P1627 or P1683? | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 4.8L, 5.3L, or 6.0L or Diagnostic Trouble Code (DTC) List in Engine Controls - 8.1L | Go to Step 6 | |||||||||||
Does the scan tool display DTC B1367? | Go to Diagnostic Trouble Code (DTC) List in Instrument Panel, Gauges, and Console | Go to Step 7 | |||||||||||
Does the scan tool display DTC C0470, C0506, C0521, or C0895? | Go to Diagnostic Trouble Code (DTC) List in Variable Effort Steering | Go to Step 8 | |||||||||||
Does the scan tool display DTC C0550, C0551 or C0870? | Go to Diagnostic Trouble Code (DTC) List in Real Time Damping (RTD) |
