LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2002 >> MX-5 Miata LS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P1633: Battery Overcharge >> Diagnostic Procedure

Diagnostic Procedure

  1. Turn ignition off. Connect New Generation Star (NGS) tester or equivalent to OBD-II Data Link Connector-2 (DLC-2). See Figure. Turn ignition on. Monitor for FREEZE FRAME DATA and ensure data has been recorded. Check for service bulletins and/or other line of repair information related to this DTC. If repair information is available, perform diagnosis and repair as necessary. After repair, go to step  7. If repair information is not available, go to next step.
  2. Turn ignition off. Disconnect generator 2-pin harness connector. See Figure. Check for poor connection at generator connector terminals due to damaged, pulled-out pins, corrosion, etc. If connector terminals are okay, go to next step. If connector terminals are faulty, repair or replace as necessary. After repair, go to step  7.
  3. With generator harness connector disconnected, turn ignition on. Measure voltage between ground and generator harness connector terminals "D" (Gray/Red wire). If battery voltage is found, go to next step. If battery voltageis not found, possible malfunction at generator, go to step  6. For circuit identification, see MIATA in WIRING DIAGRAMS article.
  4. Turn ignition off. Disconnect PCM 24-pin harness connector. See Figure. Check for poor connection at PCM connector terminals due to damaged, pulled-out pins, corrosion, etc. If connector terminals are okay, go to next step. If connector terminals are faulty, repair or replace as necessary. After repair, go to step  7.
  5. With generator and PCM harness connectors disconnected, turn ignition on. Measure voltage between ground and generator harness connector terminal "D" (Gray/Red wire). If battery voltage is found, repair short circuit to battery voltage (in Gray/Red wire) between generator and PCM. After repair go to step  7. If battery voltage is not found, go to step  7.
  6. With generator harness connector disconnected and ignition on, measure voltage between ground and generator connector terminal "D" (component side). If battery voltage is not found, go to next step. If battery voltage is found, repair or replace generator (internal failure). After repair go to next step.
  7. Return vehicle to original condition. Using NGS tester or equivalent, clear DTCs from PCM memory. Start engine and let it idle until it reaches normal operation temperature. Monitor for DTCs. If same DTC P1631 is present, replace PCM. For PCM removal and installation, see POWERTRAIN CONTROL MODULE in REMOVAL, OVERHAUL & INSTALLATION article. If any other DTC is present, follow appropriate DTC diagnostic procedure.
scientia non olet · About LEMON Manuals