Circuit/System Testing

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

Crank the engine for up to 30 seconds.
Observe the engine DTC information with a scan tool.
- If DTCs P0102, P0171, P0201, P0230, P0335, P0336, P0340, P0443, P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P0685, P0689, P0690, P1516, P1682, P2610 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose those DTCs.
Install a spark tester.
Crank the engine for 15 seconds. Spark should be observed from the spark tester.
- If spark is not observed, refer to Electronic Ignition (EI) System Diagnosis .

IMPORTANT: Additional DTCs may set when using the fuel pump output control.

Command the fuel pump ON and OFF. The fuel pump should energize when commanded ON and de-energize when commanded OFF
- If the fuel pump does not respond, refer to Fuel System Diagnosis (RPO NT7) or Fuel System Diagnosis (RPO NU6) .
Turn OFF the ignition.
Install the CH-48027-100 . Turn ON the ignition and command the fuel pump ON while observing the CH-48027-100 . Refer to Fuel Pressure Gage Installation and Removal . The fuel pressure should be between 345-414 kPa (50-60 psi).
- If the fuel pressure is not within 345-414 kPa (50-60 psi), refer to Fuel System Diagnosis (RPO NT7) or Fuel System Diagnosis (RPO NU6) .
Inspect for the following conditions:
- Compare the actual engine coolant temperature to the ECT parameter.
- The air filter and air intake system for restrictions and obstructions
- Test the fuel for contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
- Inspect the spark plugs-Refer to Spark Plug Inspection .
- Test the exhaust system for restrictions. Refer to Restricted Exhaust .
- Engine mechanical conditions such as worn timing chain gears, low compression, etc.-Refer to Engine Compression Test .