DRIVEABILITY - NGC
Symptom:
P1686-NO SKIM BUS MESSAGES
INTERMITTENT CONDITION
PCI BUS CIRCUIT OPEN FROM PCM TO SKIM
LOSS OF SKIM COMMUNICATION
SKIM/PCM
TEST
1
Turn the ignition on.
With the DRBIII , read the DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Yes → Go To 2
No
2
Turn the ignition on.
With the DRB III, attempt to communicate with the SKIM.
NOTE: This test will indicate if the Bus is operational from the DLC to the
SKIM.
Was the DRB III able to communicate with the SKIM?
Yes → Go To 3
No
3
Turn the ignition off.
Disconnect the PCM harness connectors.
Disconnect the SKIM harness connector.
CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING
THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMI-
NALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL
MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.
Measure the resistance of the PCI Bus circuit from the SKIM harness connector to
the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes → Go To 4
No
POSSIBLE CAUSES
ACTION
→ Go To 5
→ Refer to symptom BUS +/- SIGNAL OPEN FROM SKIM in the
COMMUNICATION category.
Perform SKIS VERIFICATION.
→ Repair the PCI Bus circuit between the PCM and the SKIM for an
open.
Perform SKIS VERIFICATION.
274
APPLICABILITY
All
All
All