Test G: Audio Control Module Does Not Respond To NGS Tester
NOTE:
Audio control module may also be referred to as audio unit.
- Turn ignition switch to LOCK position. Disconnect Audio Control Module (ACM) 20-pin harness connector C240a. ACM is located behind center of instrument panel, on radio. Inspect harness connector for loose, damaged or corroded terminals. If problem does not exist, go to next step. If problem exists, repair harness connector as necessary and retest system for normal operation.
- Connect ACM 20-pin harness connector C240a. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). DLC is located below driver's side of instrument panel, to right of steering column. Turn ignition switch to RUN position. Perform data link diagnostic test. See DATA LINK DIAGNOSTIC TEST under SELF-DIAGNOSTIC SYSTEM. If NGS tester indicates ACM: NO RESPONSE ON CKT 914 (BUS +), go to next step. If NGS tester indicates ACM: NO RESPONSE ON CKT 915 (BUS -), go to step 6 .
- Turn ignition switch to LOCK position. Disconnect NGS tester. Disconnect ACM 20-pin harness connector C240a. Measure resistance between ACM harness connector C240a terminal No. 3 (Gray/Black wire) and DLC terminal No. 2 (Gray/Red wire). See Figure and Fig 1 . If resistance is greater than 5 ohms, go to next step. If resistance is 5 ohms or less, replace ACM and retest system for normal operation.
- Disconnect 22-pin joint connector No. 4 harness connector C223. Joint connector No. 4 is located behind left side of instrument panel. Measure resistance in Gray/Black wire between joint connector No. 4 harness connector C223 terminal No. 16 and ACM harness connector C240a terminal No. 3. See Figure and Fig 1 . If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in Gray/Black wire between joint connector No. 4 and ACM. Retest system for normal operation.
- Measure resistance between joint connector No. 4 terminals No. 14 and 16 (component side). See Figure . If resistance is 5 ohms or less, repair open in Gray/Red wire between joint connector No. 4 and DLC. Retest system for normal operation. If resistance is greater than 5 ohms, replace joint connector No. 4 and retest system for normal operation.
- Turn ignition switch to LOCK position. Disconnect NGS tester. Disconnect ACM 20-pin harness connector C240a. Measure resistance between ACM harness connector C240a terminal No. 4 (Blue/Yellow wire) and DLC terminal No. 10 (Blue/Red wire). See Figure and Fig 1 . If resistance is greater than 5 ohms, go to next step. If resistance is 5 ohms or less, replace ACM and retest system for normal operation.
- Disconnect 22-pin joint connector No. 4 harness connector C223. Joint connector No. 4 is located behind left side of instrument panel. Measure resistance in Blue/Yellow wire between joint connector No. 4 harness connector C223 terminal No. 7 and ACM harness connector C240a terminal No. 4. See Figure and Fig 1 . If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in Blue/Yellow wire between joint connector No. 4 and ACM. Retest system for normal operation.
- Measure resistance between joint connector No. 4 terminals No. 7 and 9 (component side). See Figure . If resistance is 5 ohms or less, repair open in Blue/Red wire between joint connector No. 4 and DLC. Retest system for normal operation. If resistance is greater than 5 ohms, replace joint connector No. 4 and retest system for normal operation.