Bus +/- Signal Open Or No Response From SKIM
NOTE:
After making any repairs, perform SKIS VERIFICATION TEST under VERIFICATION TESTS.
- Turn the ignition on. With the DRBIII®, enter BODY then ELECTRO/MECH CLUSTER (MIC). If the DRBIII® was able to I/D or communicate with the MIC, go to the next step. If the DRBIII was not able to I/D or communicate with the MIC, refer to the symptom index for problems related to no communication with the MIC. See SYMPTOM INDEX table under SELF-DIAGNOSTIC SYSTEM.
- Turn the ignition off. Disconnect the SKIM harness connector. Measure the resistance between ground and the ground circuit. If the resistance is below 5.0 ohms, go to the next step. If the resistance is above 5.0 ohms, repair the ground circuit for an open.
- Turn the ignition off. Disconnect the SKIM harness connector. See Fig 1. Turn the ignition on. Using a 12-volt test light connected to ground, probe the fused ignition switch output circuit. If the test light illuminated, go to the next step. If the test light did not illuminate, repair the fused ignition switch output circuit for an open.
- Turn the ignition off. Disconnect the SKIM harness connector. Using a 12-volt test light connected to ground, probe the fused B+ circuit. If the test light illuminated, go to the next step. If the test light did not illuminate, repair the fused B+ circuit for an open.
- Disconnect the SKIM harness connector. Use Scope Input Cable (CH7058), Cable-To-Probe adapter (CH7062), and the Red and Black test probes. Connect the Scope Input Cable to the channel one connector on the DRBIII. Attach the Red and Black leads and the Cable-To-Probe Adapter to the Scope Input Cable. With the DRBIII® select PEP MODULE TOOLS. Select LAB SCOPE. Select LIVE DATA. Select 12 VOLT SQUARE WAVE. Press F2 for scope. Press F2 and use the down arrow to set voltage range to 20 volts. Set probe to x10. Press F2 again when complete. Connect the Black lead to the chassis ground. Connect the Red lead to the PCI bus circuit in the SKIM connector. Turn the ignition on. Observe the voltage display on the DRBIII lab scope. If the voltage pulses from 0 to approximately 7.5 volts, go to the next step. If the voltage does not pulse from 0 to approximately 7.5 volts, repair the PCI bus circuit for an open.
- If there are no possible causes remaining, replace and program the sentry key immobilizer module. See SENTRY KEY IMMOBILIZER MODULE under REMOVAL & INSTALLATION. See SENTRY KEY IMMOBILIZER MODULE (SKIM) under PROGRAMMING.
NOTE:
Ensure there is PCI Bus communication with other modules on the vehicle before proceeding. If not, refer to the symptom index and repair as necessary. See SYMPTOM INDEX table under SELF-DIAGNOSTIC SYSTEM.