Chart B, Loss Of Serial Data (Non-CRT Equipped)
NOTE:
The Electronic Control Module (ECM) may be referred to as the Powertrain Control Module (PCM) in diagnostic charts and figures. The 2 terms may be used interchangeably.
IPC indicates loss of serial data communication by displaying the message ELECTRICAL PROBLEM. All other segments are blank. If display is fully illuminated and ELECTRICAL PROBLEM message is displayed, enter diagnostics and proceed to appropriate code chart. DO NOT use CHART A. Loss of serial data communications can occur for the following reasons:
- Short to ground anywhere in circuit No. 800
- Short to voltage anywhere in circuit No. 800
- Two opens in circuit No. 800
- Internal BCM or IPC fault
- Open in ECCP ground circuit or IGN 3 circuit.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- This step checks to see if ECCP has lost data communication along with IPC.
- Since IPC has lost data communications, shorting terminal "M" at ALDL connector should NOT remove data communications from ECCP. If this does happen, IPC is receiving data but is unable to communicate due to poor connection or an internal problem.