DTC P1686: No Skim Bus Message Received: Testing
- Turn ignition on. Using scan tool, read PCM DTCs. If DTC P1686 is present and STARTS SINCE SET counter is equal to zero, go to next step. If DTC P1686 is not present and STARTS SINCE SET counter is not equal to zero, go to step 5 .
- Using scan tool, attempt to communicate with SKIM. If scan tool communicates with SKIM, go to next step. If scan tool does not communicate with scan tool, go to BUS +/- SIGNAL OPEN FROM SKIM under COMMUNICATIONS SYSTEM under SYSTEM TESTS in BODY CONTROL MODULES - CONCORDE, INTREPID, LHS & 300M article in ACCESSORIES & EQUIPMENT.NOTE: PCI bus circuit (Violet/Yellow wire) between PCM and SKIM runs through Body Control Module (BCM).
- Turn ignition off. Disconnect PCM harness connectors. See Figure . Disconnect SKIM harness connector. SKIM is located on steering column. Measure resistance of Violet/Yellow wire between terminal No. 2 at SKIM harness connector and terminal No. 59 at PCM C2 harness connector. See Figure and Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair PCI bus circuit (Violet/Yellow wire) between PCM and SKIM. See WIRING DIAGRAMS article.
- Turn ignition off. Replace SKIM. Turn ignition on. Using scan tool, display and clear all PCM and SKIM DTCs. Perform 5 ignition key cycles leaving ignition on for 90 seconds per cycle. Using scan tool, read PCM DTCs. If DTC P1686 is displayed, replace PCM. If DTC P1686 is not displayed, test is complete.
- Conditions that set DTC are not present at this time. Perform the following to help identify intermittent condition:
- With engine running at normal operating temperature, wiggle related wiring harness while monitoring related parameters on scan tool. If voltage changes or DTC sets while wiggling wiring harness, repair connectors or wiring harness where wiggling caused voltage to change or DTC to set.
- Review freeze frame information on scan tool. Duplicate conditions present when DTC was set.
- Refer to any technical service bulletins that may apply.
- Visually inspect related wiring harness. Check for chafed, pierced, pinched or partially broken wires.
- Visually inspect related wiring harness connectors. Check for broken, bent, pushed out or corroded terminals.
If a problem is found, repair as necessary. If no problems are found, test is complete.