Diagnostic Aids

Purpose of this test is to verify Powertrain Control Module (PCM) power-up during cranking. Lack of power at PCM during cranking can cause a no-start condition and a fault code loss.

1. Check VPWR PID
   
   Connect New Generation Star (NGS) scan tool to Data Link Connector (DLC). Using scan tool, access VPWR PID from PID/DATA monitor menu. See ADDITIONAL SYSTEM FUNCTIONS in SELF-DIAGNOSTICS - EEC-V (DIESEL) article. Crank engine while monitoring PID reading. If PID reading indicates 8 volts or more, go to next step. If PID reading indicates less than 8 volts, check charging circuit, power and ground circuits. See TEST A under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (DIESEL) article.
2. Check RPM PID
   
   Using scan tool, access RPM PID from PID/DATA monitor menu. Crank engine while monitoring PID reading. If PID reading indicates 100 RPM or more, go to next step. If PID reading indicates less than 100 RPM, check Camshaft Position (CMP) sensor circuit. See TEST DG in SELF-DIAGNOSTICS - EEC-V (DIESEL) article.
3. Check ICP PID
   
   Using scan tool, access ICP PID from PID/DATA monitor menu. Crank engine while monitoring PID reading. If PID reading indicates 500 psi (3448 kPa) or more, go to next step. If PID reading indicates less than 500 psi (3448 kPa), injectors are not being energized because of insufficient pressure. Perform INJECTION CONTROL PRESSURE LEAK TEST .
4. Check Fuel Pulse Width
   
   Using scan tool, access FUEL PW PID from PID/DATA monitor menu. Crank engine while monitoring PID reading. If PID reading indicates 1-6 milliseconds, go to GLOW PLUG SYSTEM OPERATION TEST . If PID reading does not indicate 1-6 milliseconds and VPWR, RPM and ICP PID readings are correct, check for Camshaft Position (CMP) sensor signal fault. See TEST DG in SELF-DIAGNOSTICS - EEC-V (DIESEL) article.