Control Unit Input Test
- Before testing, troubleshoot the multiplex control system (see TROUBLESHOOTING ).
- Remove the driver's dashboard lower cover (see DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION ).
- Disconnect the under-dash fuse/relay box connectors K, P, Q and Y.NOTE: All connectors are shown from wire side of female terminals.
- Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 5.
- With the connectors still disconnected, make these input tests at the connector.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 6.REFERENCE TABLE
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained K10 WHT/GRN Disconnect the gauge control module 36P connector Check for continuity between the K10 terminal and the gauge control module 36P connector No. 27 terminal: There should be continuity. An open in the wire Check for continuity to ground: There should be no continuity. Short to ground in the wire
- Reconnect the connectors to the under-dash fuse/relay box, and make these input tests at the appropriate connectors on the under-dash fuse/relay box.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 7.REFERENCE TABLE
Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained Y6 BLK Under all conditions Measure voltage to ground: There should be less than 0.5 V. - Poor ground (G502)
- An open in the wire
P18 RED Hatch or tailgate open Measure voltage to ground: There should be less than 0.5 V. - Faulty tailgate latch switch
- Faulty hatch latch switch
- An open in the wire
Hatch and tailgate closed Measure voltage to ground: There should be battery voltage. - Faulty tailgate latch switch
- Faulty hatch latch switch
- Short to ground in the wire
Q3 GRN Driver's door or left rear door open Measure voltage to ground: There should be less than 0.5 V. - Faulty driver's door switch
- Faulty left rear door switch
- An open in the wire
Driver's door and left rear door closed Measure voltage to ground: There should be battery voltage. - Faulty driver's door switch
- Faulty left rear door switch
- Short to ground in the wire
Q4 GRY/BLK Passenger's door or right rear door open Measure voltage to ground: There should be less than 0.5 V. - Faulty passenger's door switch
- Faulty right rear door switch
- An open in the wire
Passenger's door and right rear door closed Measure voltage to ground: There should be battery voltage. - Faulty passenger's door switch
- Faulty right rear door switch
- Short to ground in the wire
- Perform the Gauge Self-diagnostic Procedure (see SELF-DIAGNOSTIC FUNCTION
).
- If the safety indicator blinks, go to step 8.
- If the safety indicator does not blinks, replace the gauge control module.
- Substitute a known-good under-dash fuse/relay box and recheck the system.
- If the symptom is gone, the multiplex control unit is faulty; replace the under-dash fuse/relay box.
- If the symptom is still present, the gauge control module must be faulty; replace the gauge control module.