Test K: No Communication With Driver's Seat Module

CAUTION: Side air bag system must be deactivated for diagnosis of power seat (if equipped). See AIR BAG RESTRAINT SYSTEMS - EXPLORER & MOUNTAINEER article. Air Bag Simulator (418-F088) must be installed under seats to floor connector, and removed before operating vehicle.

NOTE: Before beginning this test, ensure seat and seat track are free from all obstructions.

Deactivate air bag system. See AIR BAG RESTRAINT SYSTEMS - EXPLORER & MOUNTAINEER article. If vehicle is equipped with memory seat/mirror feature, go to next step. If vehicle is not equipped with memory seat/mirror feature, test power seats for proper operation. If seats do not operate properly, repair by symptom. See SYMPTOM INDEX table.
Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Ensure transmission is in Park. Turn ignition switch to RUN position. Using NGS tester, monitor Driver's Seat Module (DSM) PID P/N_SW. If NGS tester displays UNABLE TO PERFORM TEST/FUNCTION, MODULE NOT RESPONDING: DSM, CHECK IGNITION STATUS, VERIFY CABLE REQUIREMENTS or CHECK CABLE CONNECTIONS, go to next step. If NGS tester does not display UNABLE TO PERFORM TEST/FUNCTION, MODULE NOT RESPONDING: DSM, CHECK IGNITION STATUS, VERIFY CABLE REQUIREMENTS or CHECK CABLE CONNECTIONS, go to step 8 .
Turn ignition switch to LOCK position. Remove fuse No. 18 (25-amp) from Central Junction Box (CJB). If fuse is okay, go to next step. If fuse is blown, go to step 5 .
Turn ignition switch to RUN position. Measure voltage between ground and input side of CJB fuse No. 9 (7.5-amp). If more than 10 volts exist, go to step 6 . If 10 volts or less exist, replace CJB. Recheck system operation.
Turn ignition switch to LOCK position. Ensure fuse No. 18 is still removed. Remove fuse No. 9 (7.5-amp) from CJB. Disconnect DSM 22-pin harness connector C337. Measure resistance between ground and DSM harness connector C337 terminal No. 12 (Light Green/Yellow wire). See Figure . If resistance is more than 10 k/ohms, system is okay at this time. Replace fuse and recheck system operation. If resistance is 10 k/ohms or less, repair short to ground in Light Green/Yellow wire between CJB and DSM. Recheck system operation.
Turn ignition switch to LOCK position. Install fuse No. 36 (7.5-amp). Disconnect DSM 22-pin harness connector C337. Turn ignition switch to RUN position. Measure voltage between ground and DSM harness connector C337 terminal No. 12 (Light Green/Yellow wire). See Figure . If more than 10 volts exist, go to next step. If 10 volts or less exist, repair open in Light Green/Yellow wire between CJB and DSM. Recheck system operation.
Turn ignition switch to LOCK position. Measure resistance between ground and DSM harness connector C337 terminal No. 11 (Black/White wire). If resistance is less than 5 ohms, repair network concern. See MODULE COMMUNICATIONS NETWORK - EXPLORER & MOUNTAINEER article. If resistance is 5 ohms or more, repair open or high resistance in Black/White wire between DSM and ground. Ground point is located in left front of engine compartment, near radiator.
Using NGS tester, monitor DSM PID P/N_SW while moving transmission through entire range. If PID value does not agree with transmission position, go to next step. If PID value agrees with transmission position, replace DSM. Recheck system operation.
Remove fuse No. 28 (7.5-amp) from CJB. Disconnect DSM 22-pin harness connector C337. Measure resistance of Red/Black wire between output side of fuse No. 28 and DSM harness connector C337 terminal No. 20. See Figure . If resistance is less than 5 ohms, check Transmission Range (TR) sensor circuit. Repair as necessary. See appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS. If resistance is more than 5 ohms, repair open or high resistance in Red/Black wire. Recheck system operation.