LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2001 >> Grand Cherokee Limited, 4.0 S, AWD >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Modules >> System Tests >> Communications >> No Response From Transmission Control Module
April 5, 2026: LEMON Manuals is launched! Read the announcement.

No Response From Transmission Control Module

NOTE: Following procedures require a 12-volt test light. If test light illumination is in question, compare brightness of test light when testing circuit, to brightness of test light when connected directly to battery positive post.
  1. Using scan tool, attempt communications with Air Bag Control Module (ACM) and Body Control Module (BCM). If scan tool was able to identify or establish communications with both modules, go to next step. If scan tool was unable to identify or establish communications with either modules, go to PCI BUS COMMUNICATION FAILURE  . Perform TRANSMISSION VERIFICATION TEST  under VERIFICATION TESTS.
  2. Turn ignition switch to OFF, then to LOCK position. Disconnect TCM connector. See COMPONENT LOCATIONS  . Turn ignition on. Connect test light between ground and TCM connector terminal No. 11 (Orange/Dark Blue wire). See Fig 1 . If test light illuminates brightly, go to next step. If test light illuminates dim or does not illuminate at all, repair open or high resistance in Orange/Dark Blue wire between TCM and fuse No. 12 (10-amp) located in junction block. Also check for poor connections at junction block and TCM. See Figure . Perform TRANSMISSION VERIFICATION TEST  under VERIFICATION TESTS.
  3. Turn ignition switch to OFF, then to LOCK position. Remove engine starter motor relay from Power Distribution Center (PDC). See Figure . Connect test light between ground and TCM connector terminal No. 8 (Yellow/Red wire). Turn ignition switch to START position. If test light illuminates brightly, go to next step. If test light illuminates dim or does not illuminate at all, repair open or high resistance in Yellow/Red wire between TCM and fuse No. 31 (10-amp) located in junction block. Also check for poor connections at junction block and TCM. Perform TRANSMISSION VERIFICATION TEST  under VERIFICATION TESTS.
  4. Turn ignition switch to OFF, then to LOCK position. Connect test light between ground and TCM connector terminal No. 56 (Red/White wire). If test light illuminates brightly, go to next step. If test light illuminates dim or does not illuminate at all, repair open or high resistance in Red/White wire between TCM and fuse No. 5 (30-amp) located in PDC. Also check for poor connections at junction block and PDC. Perform TRANSMISSION VERIFICATION TEST  under VERIFICATION TESTS.
  5. Connect test light between battery positive post and TCM connector Black/Red wire terminals No. 37, 39, and 57. If test light illuminates brightly, go to next step. If test light illuminates dim or does not illuminate at all, repair open or high resistance in appropriate Black/Red wire between TCM and ground. Also check for poor connection at ground G102 located on lower right side of engine, behind right motor mount. Perform TRANSMISSION VERIFICATION TEST  under VERIFICATION TESTS.
    6. NOTE: Ensure PCI bus communication between other modules exists before proceeding. If PCI bus module communication does not exist between other modules, go to appropriate system test. See SYMPTOM IDENTIFICATION  table under RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM.
  6. Use Scope Input Cable (CH7058), Cable-To-Probe Adapter (CH7062) and Red and Black test probes. Connect scope input cable to channel one connector on scan tool. Attach Red and Black test probes and cable-to-probe adapter to scope input cable. Select scan tool STANDALONE function. Select LAB SCOPE. Select LIVE. Select 12 VOLT SQUARE WAVE. Press F2 for scope display. Press F2 and use down arrow to select voltage range to 20 volts. Press F2 after selecting 20 volts. Connect Black test probe lead to ground and Red test probe lead to TCM connector terminal No. 43 (Yellow/Violet wire). See Figure . Turn ignition on. Observe voltage readings on scan tool. If reading pulses from zero to approximately 7.5 volts, go to next step. If reading is steady at zero volts, repair PCI bus circuit (Yellow/Violet wire) between TCM and diagnostic junction port. See DATA LINK CONNECTORS article in WIRING DIAGRAMS. Perform TRANSMISSION VERIFICATION TEST  under VERIFICATION TESTS.
  7. Replace TCM. See TRANSMISSION CONTROL MODULE  under REMOVAL & INSTALLATION. Perform TRANSMISSION VERIFICATION TEST  under VERIFICATION TESTS.
Fig 1: Identifying Transmission Control Module Connector Terminals
G92I05780Courtesy of DAIMLERCHRYSLER CORP.
scientia non olet · About LEMON Manuals