Diagnosis & Repair Procedure
- If engine system check has been performed, go to next step. If engine system check has not been performed, go to A4: ENGINE SYSTEM CHECK under SYSTEM TESTS.
- Check starting system operation. If engine does not crank or cranks slowly, repair starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS. If starting system is okay, go to next step.
- Using scan tool, check for current or pending DTC P1500. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If DTC is present, go to DTC P1500 test. If DTC P1500 is not present, go to next step.
- Turn ignition off. Disconnect CMP sensor 4-pin harness connector. CMP sensor is located on rear of cylinder head. Turn ignition on. Measure voltage between CMP sensor harness connector terminals No. 1 (Gray/Yellow wire) and No. 2 (Blue/Black wire). If voltage reading is 10-14 volts, go to step 6. If voltage reading is not 10-14 volts, go to next step.
- Check for open or short in Gray/Yellow wire between CMP and ECM harness connector C51-3. See WIRING DIAGRAMS
article. Also, check for open or short in Blue/Black wire between CMP and main relay. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
- Check CMP sensor (REF) signal. Turn ignition off. Reconnect CMP sensor harness connector. Disconnect all ignition coil assembly and fuel injector connectors. Access ECM. ECM is located under instrument panel, behind glove box. See Figure. Turn ignition on. Backprobing at ECM, measure voltage between ECM connector C51-3 terminal No. 26 (Gray/Yellow wire) and ECM connector C51-1 terminal No. 13 (Yellow/Blue wire) while slowly turning crankshaft. See Figure. If voltage reading toggles between 0-1 volt and 3-5.25 volts 4 times when crankshaft is turned 2 revolutions, leave ignition coil and fuel injector harness connectors disconnected and go to step 9. If reading does not toggle between 0-1 volt and 3-5.25 volts 4 times when crankshaft is turned 2 revolutions, go to next step.
- Check for open or short in Yellow/Blue wire between CMP sensor and ECM. See WIRING DIAGRAMS
article. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If no problem with wiring is found, go to next step.
- Replace CMP sensor. After repair, repeat DTC CONFIRMATION TEST . If problem persists, substitute a known good ECM, and repeat DTC CONFIRMATION TEST .
- Check CMP sensor (POS) signal. Access ECM. ECM is located under instrument panel, behind glove box. See Figure. Backprobing at ECM, measure voltage between ECM connector C51-3 terminal No. 26 (Gray/Yellow wire) and ECM connector C51-1 terminal No. 12 (Yellow/Green wire) while slowly turning crankshaft. See Figure. If voltage reading toggles between 0-1 volt and 3-5.25 volts 6 times when crankshaft is turned 2 revolutions, go to step 12. If voltage reading does not toggle between 0-1 volt and 3-5.25 volts 6 times when crankshaft is turned 2 revolutions, go to next step.
- Check for open or short in Yellow/Green wire between CMP sensor and ECM. See WIRING DIAGRAMS
article. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If no problem with wiring is found, go to next step.
- Replace CMP sensor. After repair, repeat DTC CONFIRMATION TEST . If problem persists, substitute a known good ECM, and repeat DTC CONFIRMATION TEST .
- Disconnect ECM 28-pin harness connector C51-1 and ECM 26-pin harness connector C51-3. ECM is located under instrument panel, behind glove box. See Figure. Check for poor terminal contact at ECM harness connectors. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If no problem with wiring is found, go to next step.
- Substitute a known good ECM, and repeat DTC CONFIRMATION TEST . If DTC does not reset, testing is complete.
Courtesy of SUZUKI OF AMERICA CORP.