LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2001 >> MX-5 Miata Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P1601: Pcm-TCM Communication Line Error >> Diagnosis & Repair Procedure

Diagnosis & Repair Procedure

  1. Check for related service bulletins. Repair as necessary and go to next step.
  2. Turn ignition off. Using scan tool, access PID data for RTQ1 and RTQ2. Upshift and downshift transmission wile driving vehicle. If RTQ1 and RTQ2 PIDs don't change, go to next step. If RTQ1 and RTQ2 PIDs change, go to step  8.
  3. Turn ignition off. Disconnect appropriate PCM connectors. Check connector for loose or damaged terminals, poor contact or corrosion. Repair as necessary and go to step  8. If no problem is found, go to next step.
  4. Turn ignition on. Measure voltage between ground and PCM harness connector terminal No. 4Z (Pink/Black wire). See Figure. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, check for open or short in Pink/Black wire. See WIRING DIAGRAMS article. Repair as necessary and go to step  8.
  5. Turn ignition off. Disconnect TCM connector. Check connector for loose or damaged terminals, poor contact or corrosion. Repair as necessary and go to step  8. If no problem is found, go to next step.
  6. Reconnect PCM connector. Turn ignition on. Measure voltage between ground and TCM harness connector terminal AL (Violet/Green wire). See Figure. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, repair open or short in Violet/Green wire. See WIRING DIAGRAMS article. Go to step  8.
  7. Turn ignition off. Reconnect all connectors. Using scan tool, check for TCM DTCs and voltage. If TCM is okay, go to next step. If any problem is present, replace TCM and go to next step.
  8. Reconnect all connectors. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Start engine. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTC P1601 is present, replace PCM and go to next step. On vehicles equipped with immobilizer system, reprogram ignition key identification numbers. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. If DTC P1601 is not present, go to next step.
  9. Cycle ignition from off to on. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to appropriate test.
scientia non olet · About LEMON Manuals