LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 130 (Engine Control System - Basic Diagnostic Procedures) >> No-Start Diagnosis >> No Start - Engine Cranks Okay (5.7L) >> Ignition System Diagnosis ("Y" Body)

Ignition System Diagnosis ("Y" Body)

WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2002 Saturn SL2, 2002 Saturn SL1, 2002 Saturn SL, 2002 Saturn SC2, and 2002 Saturn SC1. However, it is still accessible from the selected car via links, so may be relevant.
  1. If diagnostic system check has already been performed, go to next step. If diagnostic system check has not been performed, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS in appropriate SELF-DIAGNOSTICS article.
  2. Turn ignition on. Using test light connected to ground, probe terminals of the following fuses, located in underhood electrical center No. 2:
    • A/C
    • ENG IGN1
    • INJR1
    • INJR2
    • THROT CONT

    If test light illuminates on both sides of all fuses, go to next step. If test light does not illuminate, diagnose ignition relay circuit. See IGNITION RELAY CIRCUIT (5.7L)  under BASIC IGNITION SYSTEM CHECKS.

  3. Using scan tool, check for DTCs. If any DTCs related to Throttle Actuator Control (TAC) system are set, diagnose DTCs. See appropriate SELF-DIAGNOSTICS article. If DTCs are not set, go to next step.
  4. Using scan tool, check for DTCs. If any DTCs related to vehicle theft deterrent system are set, this indicates a problem with column lock or VTD fuel enable circuit. See appropriate BODY CONTROL MODULE article in ACCESSORIES & EQUIPMENT. If DTC P0230, P0335, P0336, P0601, P0602, P0604 or P0606 is set, diagnose DTCs. See appropriate SELF-DIAGNOSTICS article. If DTCs are not set, go to next step.
  5. Using scan tool, check for DTCs while cranking engine. If DTCs set while cranking engine, diagnose DTCs. See appropriate SELF-DIAGNOSTICS article. If no DTCs set, go to next step.
  6. Using scan tool, monitor engine speed while cranking engine. If engine RPM is indicated on scan tool, go to step  10. If engine RPM is not indicated on scan tool, go to next step.
  7. Turn ignition off. Disconnect CKP sensor harness connector. Measure voltage between ground and ignition feed circuit at CKP sensor harness connector. If voltage is near battery voltage, go to step  14. If voltage is not near battery voltage, go to next step.
  8. Disconnect CMP sensor harness connector. Measure voltage between ground and ignition feed circuit at CMP sensor harness connector. If voltage is near battery voltage, go to step  15. If voltage is not near battery voltage, go to next step.
  9. Check for short to ground in CKP sensor and CMP sensor ignition feed circuits. Repair as necessary. After repairs, go to step  17. If circuits are okay, go to step  16.
  10. Using scan tool, monitor engine coolant temperature. If scan tool value is close to actual engine temperature, go to next step. If scan tool value is not close to actual engine temperature, diagnose using diagnostic procedure for DTC P0118. See appropriate SELF-DIAGNOSTICS article.
  11. Using scan tool, command fuel pump on. If fuel pump runs, go to next step. If fuel pump does not run, diagnose fuel pump relay circuit. See FUEL PUMP ELECTRICAL CIRCUIT ("Y" BODY) .
  12. Turn ignition off. Connect fuel pressure gauge. See BASIC FUEL SYSTEM CHECKS . Turn ignition on. Check fuel pressure. If pressure is 55-62 psi (3.9-4.4 kg/cm2 ), go to next step. If pressure is not as specified, diagnose fuel system. See FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  13. Check for air leaks in ducts between MAF sensor and throttle body. A faulty MAF sensor may cause a no-start or stalling after start condition. Disconnecting MAF sensor will cause PCM to default to speed density (MAP, IAT, RPM) to calculate load and intake airflow. If fault condition is corrected by disconnecting MAF sensor, or connections are okay, replace MAF sensor. Check if spark plugs are gas fouled by a rich condition. Check for engine mechanical failure causing a no-start condition (i.e. timing chain, low compression, etc.). Compare MAP/BARO parameters to a similar vehicle and ensure values are similar. If a problem is found and repaired, go to step  17. If no problem is found, check for intermittent problem. See appropriate TROUBLE SHOOTING - NO CODES article.
  14. Replace CKP sensor. After repairs, go to step  17.
  15. Replace CMP sensor. After repairs, go to step  17.
  16. Replace PCM. Perform PCM relearn procedure. After repairs, go to next step.
  17. Using scan tool, clear DTCs. Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts and stalls, go to step  2.
  18. Allow engine to reach normal operating temperature. Using scan tool, check for DTCs. If any DTCs are set, diagnose DTCs. See appropriate SELF-DIAGNOSTICS article. If no DTCs are set, go to next step.
  19. Using scan tool, select CAPTURE INFO, REVIEW INFO function. Check for any additional DTCs that have not been diagnosed. If additional DTCs are set, diagnose DTCs. See appropriate SELF-DIAGNOSTICS article. If no additional DTCs are set, system is okay.
scientia non olet · About LEMON Manuals