Circuit/System Verification
IMPORTANT:
This diagnostic assumes the following: system voltage levels are adequate for starter motor operation.
- The battery is completely charged. Refer to Battery Inspection/Test .
- The engine cranking speed is acceptable. Refer to Engine Cranks Slowly .
- There is adequate fuel in the fuel tank.
- Crank the engine for 15 seconds. Observe the DTC information with a scan tool. The following DTCs should not be set:
P0117, P0118, P0122, P0123, P0201, P0202, P0203, P0204, P0335, P0336, P0351, P0352, P0562, P0563, P0601, P0602, P0606, P1631, P2610 or U0101.
- If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Ignition ON, observe the Theft Deterrent parameter with a scan tool. The parameter should display Disabled.
- If Enabled is displayed, refer to Symptoms - Theft Deterrent .
- Ignition OFF, disconnect the fuel pump relay.
- Connect a J 26792 to the boot of a spark plug wire of a cylinder and a good ground.
- While cranking the engine, verify that the spark tester sparks.
- If there is no spark, refer to Electronic Ignition (EI) System Diagnosis .
- Ignition OFF, install the fuel pump relay.
- Ignition ON, command the fuel pump ON with a scan tool. You should hear the fuel pump turn ON.
- If the fuel pump does not turn ON, refer to Fuel Pump Electrical Circuit Diagnosis .
- Ignition OFF, install the J 34730-1A fuel pressure gage.
- The fuel pump may need to be commanded ON a few times, in order to obtain the highest possible fuel pressure.
- Do NOT start the engine for this test.
- Ignition ON, command the fuel pump ON with a scan tool. The fuel pressure should be between 380-427 kPa (55-62 psi).
- If the fuel pressure is not within the specified range, refer to Fuel System Diagnosis .
- Verify that the following conditions do not exist:
- Collapsed air intake duct to the throttle body
- Restricted air filter element
- Spark plugs for being gas or coolant fouled
- A skewed manifold absolute pressure (MAP) sensor-Refer to DTC P0106
- A skewed engine coolant temperature (ECT) sensor-Refer to Temperature Versus Resistance
- Exhaust system restricted-Refer to Restricted Exhaust
- Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis
- Engine mechanical condition, for example, worn timing belt or low compression. Refer to Symptoms - Engine Mechanical or Engine Compression Test
- If you find any of the above conditions, repair as necessary.
IMPORTANT:
An erratic or weak spark is considered a no spark condition.
IMPORTANT: