Serial Link External Fault
SERIAL LINK EXTERNAL FAULTWHEN MONITORED
At ignition on, after ignition on during any rolling code handshake that occurs with the PCM due to a SKIM reset, or during SECRET KEY transfers to the PCM.
SET CONDITION
When the SKIM does not receive an expected PCI BUS message transmission acknowledgement from the PCM after 3 transmit attempts.
POSSIBLE CAUSES
- Wire harness failure
- SKIM
- PCM
Diagnostic Test
1. ACTIVE DTC
NOTE: make sure the PCM has proper power and ground connections before continuing.
With the scan tool, read and record the SKIM DTCs then erase the SKIM DTCs.
Turn the ignition off.
Wait 2 minutes.
Turn the ignition on.
With the scan tool, read the SKIM DTCs.
Q: Is the DTC active at this time?
YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
2. INTERMITTENT WIRING PROBLEM
Turn the ignition off.
NOTE:
- Visually inspect the related wiring harness and PCI Bus circuits. Look for any chafed, pierced, pinched, or partially broken wires.
- Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
NOTE: Refer to any Technical Service Bulletins (TSB) that may apply.
Q: Were any problems found?
YES: Repair as necessary. Perform SKIS VERIFICATION. SKIS Verification
NO: Go To 3
3. SKIM/PCM
NOTE: Before proceeding it will be necessary to obtain the SKIM PIN.
Turn the ignition on.
With the scan tool, display and erase all PCM and SKIM DTC's.
Perform 5 ignition key cycles, leaving the ignition key on for a minimum of 90 seconds per cycle.
With the scan tool, read the SKIM DTCs.
Q: Does the code appear?
YES: Replace and program the Powertrain Control Module. Perform SKIS VERIFICATION. SKIS Verification
NO: Test complete, the conditions that set this DTC are not present at this time.