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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 82 (Engine Controls - Tests W/Codes - Body Control Computer) >> Self-Diagnostic Tests >> Test 38A - Instrument Cluster Or CMTC Illumination

Test 38A - Instrument Cluster Or CMTC Illumination

WARNING: This page is about a different car, the 1995 Plymouth Voyager, 1995 Plymouth Grand Voyager, 1995 Dodge Grand Caravan, 1995 Dodge Caravan, and 1995 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: Always turn ignition off prior to disconnecting or connecting any module connector.
NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION  . For appropriate wiring diagram, see WIRING DIAGRAMS  section at the end of this article. Perform TEST VER-1B after each repair.
  1. Turn park lamps on. If park lamps do not light, go to TEST 39A. If park lamps light, go to next step.
  2. Using scan tool, read panel lamp sensor voltage. Set dimmer switch to low and then move to high. If voltage changes from zero to 5 volts, go to step 8). If voltage does not change from zero to 5 volts, go to next step.
  3. Read panel lamp sensor voltage. If voltage is more than 4 volts, go to TEST 38B. If voltage is less than 4 volts, go to next step.
  4. Remove and inspect fuse No. 9 from fuse block. If fuse is okay, go to TEST 41A. If fuse is open, go to next step.
  5. Using scan tool in ohmmeter mode, check resistance of fuse No. 9 connector (Tan wire). If resistance is more than 5 ohms, replace fuse No. 9. If resistance is less than 5 ohms, go to next step.
  6. Turn ignition off. Disconnect Body Control Module (BCM) Natural connector. BCM is located behind left side knee panel. Check condition of connector, and clean or repair connector as necessary. If connector is okay, go to next step.
  7. Using scan tool in ohmmeter mode, check resistance of BCM Natural connector terminal No. 8 (Tan wire). If resistance is less than 5 ohms, repair short to ground in Tan wire and replace fuse No. 9. If resistance is more than 5 ohms, replace BCM and replace fuse No. 9.
  8. Turn ignition on. Set dimmer switch to CENTER position. If problem does not exist with instrument cluster illumination only, go to step 13). If problem exists with instrument cluster illumination only, go to next step.
  9. Turn ignition off. Disconnect instrument cluster connector. Using scan tool in voltmeter mode, check voltage on instrument cluster connector terminal No. 6 (Orange wire). Ensure park lamps are on and dimmer switch is in HIGH position. If voltage is less than 4 volts, repair open Orange wire. If voltage is more than 4 volts, go to next step.
  10. Using scan tool in ohmmeter mode, check resistance of instrument cluster connector terminal No. 14 (Black/Orange wire). Turn park lamps off. If resistance is more than 5 ohms, repair open Black/Orange wire. If resistance is less than 5 ohms, go to next step.
  11. If vehicle is equipped with an Electronic Instrument Cluster (EIC), repair or replace EIC. If vehicle is equipped with an electro/Mechanical Instrument Cluster (MIC), go to next step.
  12. Remove and inspect inoperative MIC lamp. If lamp is open, replace lamp. If lamp is okay, repair or replace MIC.
  13. Ensure dimmer switch is still in CENTER position. Using scan tool in voltmeter mode, backprobe BCM Natural connector terminal No. 22 (Orange wire). If voltage is less than 4 volts, replace BCM. If voltage is more than 4 volts, go to next step.
  14. Turn ignition off. Disconnect BCM Blue connector. Using scan tool in ohmmeter mode, check resistance of left pod switch Black connector terminal No. 3 (Yellow/Black wire). If resistance is more than 5 ohms, go to step 16). If resistance is less than 5 ohms, go to next step.
  15. Disconnect left pod switch Black connector. Check resistance of left pod switch Black connector terminal No. 3 (Yellow/Black wire). If resistance is more than 5 ohms, replace left pod switch. If resistance is less than 5 ohms, repair short to ground in Yellow/Black wire.
  16. Turn park lamps off. Remove and inspect inoperative panel lamp. If lamp is open, replace lamp. If lamp is okay, go to next step.
  17. Using scan tool in ohmmeter mode, check resistance of lamp connector ground circuit (Black wire). If resistance is more than 5 ohms, repair open Black wire. If resistance is less than 5 ohms, repair open Yellow/Black wire.
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