Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

Crank the engine while observing the scan tool vehicle DTC information.
- If DTCs P0033, P0102, P0171, P0201-P0208, P0230, P0335, P0336, P0340, P0403, P0404, 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.
Ignition OFF for 90 seconds, determine the current vehicle testing altitude. Ignition ON, observe the scan tool MAP Sensor parameter. Compare the parameter to the Altitude Versus Barometric Pressure table. The MAP sensor pressure parameter should be within the specified range indicated in the table.
- If the reading is not correct for your altitude, diagnose the MAP sensor. Refer to DTC P0106 .
Install a J 26792 HEI Spark Tester.
Crank the engine while observing the spark tester. The spark tester should spark.
- If spark is not observed, refer to Electronic Ignition System Diagnosis .

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

Command the fuel pump ON and OFF. 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 .
Turn OFF the ignition.
Install the CH-48027 . Turn ON the ignition and command the fuel pump ON while observing the CH-48027 . Refer to Fuel Pressure Gauge Installation and Removal . The fuel pressure should be between 384-425 kPa (55-61 psi).
- If the fuel pressure is not within 384-425 kPa (55-61 psi), refer to Fuel System Diagnosis .
Inspect for the following conditions:
- Compare the actual engine coolant temperature to the ECT parameter.
- 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 .