Diagnostic System Check: Notes
Diagnostic system check is an organized approach to identifying a problem created by an Anti-Lock Brake System (ABS) malfunction. This should be the starting point for any ABS diagnosis because it directs technician to next logical step in diagnosing a complaint.
Serial data is transmitted through EBCM serial data line terminal. Switched ignition voltage is supplied through EBCM switched ignition terminal, battery voltage through EBCM battery feed terminal and switched battery voltage through EBCM switched battery input terminal.
NOTE:
Test numbers refer to numbers on diagnostic chart. Use only 10-megohm (minimum) DVOM for all voltage and resistance tests. For identification of circuits and terminals referenced in charts and text, see WIRING DIAGRAMS .
- Indicates if EBCM is transmitting data.
- Checks for serial data line malfunction.
- Checks for proper connection of Tech 1 scan tool to DLC.
- Checks fuse for open.
- Checks fuse for open.
- Checks for high resistance in EBCM ground circuit.
- Checks for current codes.
- Checks for proper ABS warning light operation.
- Checks for history codes.