LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2000 >> Suburban C2500 >> Repair and Diagnosis >> Electrical >> Gauges >> Analog Instrument Panels - New Style >> Symptom Tests >> Test 10: Tachometer Inoperative

Test 10: Tachometer Inoperative

  1. Perform INSTRUMENT PANEL CLUSTER (IPC) DIAGNOSTIC SYSTEM CHECK before proceeding. See INSTRUMENT PANEL CLUSTER (IPC) DIAGNOSTIC SYSTEM CHECK  under SYSTEM TEST. If INSTRUMENT PANEL CLUSTER (IPC) DIAGNOSTIC SYSTEM CHECK has been performed, go to next step.
    2. NOTE: If complete IPC is inoperative, go to TEST 1: INSTRUMENT PANEL CLUSTER (IPC) INOPERATIVE .
  2. Start engine and monitor tachometer. If tachometer does not indicate any engine RPM, go to next step. If tachometer indicates any engine RPM, check for an intermittent problem caused by poor connections, a break in wire insulation, or a broken wire inside insulation. See WIRING DIAGRAMS .
  3. Turn ignition switch to OFF position. Disconnect C100 connector. Turn ignition switch to ON position. Check voltage between C100 connector terminal "K", tachometer signal circuit (White wire) and ground. If voltage is more than 9.5 volts, go to step  9. If voltage is 9.5 volts or less, go to next step.
  4. Remove IPC. See INSTRUMENT PANEL CLUSTER (IPC)  under REMOVAL & INSTALLATION. Disconnect IPC connector. Check for continuity in tachometer signal circuit (White wire) between IPC connector terminal A2 and C100 connector terminal "K". If continuity exists, go to next step. If continuity does not exist, go to step  9.
  5. Check for continuity between C100 connector terminal "K", tachometer signal circuit (White wire) and ground. If continuity exists, go to step  10. If continuity does not exist, go to next step.
  6. Check for poor connection between IPC and IPC connector. Repair connection as necessary. After repair, go to step  16. If no problems are found, go to step  15.
  7. Turn ignition switch to OFF position. Check continuity in tachometer signal circuit (White wire) between C100 connector terminal "K", and Vehicle Control Module (VCM) terminal No. 20 on 4.3L engine or No. 10 on all other engines. If continuity exists, go to next step. If continuity does not exist, go to step  11.
  8. Check continuity between ground and VCM terminal No. 20 on 4.3L engine or No. 10 on all other engines. If continuity exists, go to step  12. If continuity does not exist, go to step  13.
  9. Repair open White wire between IPC and C100 connector. After repair, go to step  16.
  10. Repair short to ground in White wire between IPC and C100 connector. After repair, go to step  16.
  11. Repair open White wire between VCM and C100 connector. After repair, go to step  16.
  12. Repair short to ground in White wire between VCM and C100 connector. After repair, go to step  16.
  13. Check for poor connections at all related components which could cause an intermittent problem. See WIRING DIAGRAMS . Repair connections as necessary. After repair, go to step  16. If connections are okay, go to next step.
  14. Reprogram VCM using special manufacturer's equipment. After repair, go to step  16.
  15. Replace IPC. See INSTRUMENT PANEL CLUSTER (IPC)  under REMOVAL & INSTALLATION. After repair, go to next step.
  16. Check tachometer operation. If system operates properly, repair is complete. If problem still exists, return to step  2.
scientia non olet · About LEMON Manuals