For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Circuit/System Description

The engine cranks but does not run is an organized approach to identify a condition which causes the engine to crank but not start. This diagnostic directs the technician to the appropriate system diagnosis.

This diagnostic assumes the system voltage levels are adequate for starter motor operation. Fuel level and fuel quality must be determined for correct diagnosis.

### Diagnostic Aids

Inspect for any of the following conditions:

• | Insufficient fuel can cause a no start condition. Thoroughly inspect the fuel delivery system for sufficient fuel volume to the fuel injectors. Inspect the fuel supply components for partial blockage or restrictions.

• | Fuel injectors with partially blocked and restricted nozzles, or a malfunctioning solenoid, can cause a no start condition. Refer to LINK (Fuel Injector Diagnosis).

• | There may be fuel spray at the fuel injectors and the indicated fuel pressure may be correct, yet there may not be enough fuel to start the engine. If the fuel injectors and the injector circuit are OK, and fuel spray is detected, the fuel injector ON time may be inadequate. If the engine control module (ECM) receives incorrect inputs from the various information sensors, the fuel delivered by the fuel injectors may be inadequate to start the engine. Check all the engine data parameters with a scan tool and compare the values indicated with the expected values or the values from a known vehicle in good condition.

• | Check the crankshaft position sensor engine reference signal with a scan tool. Observe the engine speed parameter while cranking the engine. The scan tool should indicate a steady 200-300 RPM while cranking. If erratic values, such as sudden spikes in the engine speed, are displayed, the engine reference signal is not stable enough for the engine to start and run properly.

• | Inspect the engine for good secure electrical grounds.

• | If the engine almost starts and then stalls, check for an open in the ground circuits of the crankshaft position sensor and the camshaft position sensor - Intake or camshaft position sensor - Exhaust.

• | Water or foreign material in the fuel can cause a no start or engine will not stay running condition. During freezing weather water can freeze inside the fuel system. The engine may start after 30 min in a heated repair shop. The malfunction may not recur until parked overnight in freezing temperatures. Extreme weather conditions can cause contaminated fuel to prevent the vehicle from starting.

• | A vehicle that starts and runs after being brought to the repair shop for a no start condition, may have an ignition system that is susceptible to moisture. Spray water on the ignition system components and the wiring in order to check for an engine starting or will not stay running concern.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

#### Special Tools

• | EL-26792 HEI Spark Tester

• | CH-48027 Digital Pressure Gage

For equivalent regional tools, refer to Special Tools.

### Circuit/System Verification

Attempt to start the engine. The engine should start and run.

### Circuit/System Testing

1. Crank the engine for up to 15 s.
2. Observe the vehicle DTC information with a scan tool.

⇒ | If any of the following DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose those DTCs P0201-P0204 00, P026 00, P0262 00, P0264 00, P0265 00, P0267 00, P0268 00, P0270 00, P0271 00, P0335 00, P0336 00, P0601 00, P0602 00, P0604 00, P0606 00, P0607 00, P0686 00, P0687 00, P0689 00, P2610 00.

3. Ignition OFF for 90 s, 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 B74 Manifold Absolute Pressure (MAP) Sensor. Refer to LINK (DTC P0107, 00 or P0108 00).

4. Verify the following scan tool parameters indicate Not Run to OK, when the engine is cranked:

⇒ | Cylinder 1-4 injector circuit short to volts test status

⇒ | If the parameters do not indicate the specified values, refer to DTC P0201, P0202, P0203, P0204, P0261, P0262, P0264, P0265, P0267, P0268, P0270, or P0271.

5. Observe the engine speed parameter while cranking the engine.

⇒ | If engine speed is not indicated, refer to DTC P0335 or P0336.

6. Install a EL-26792 HEI Spark Tester .
7. Crank the engine for 15 s. Spark should be observed from the EL-26792 HEI Spark Tester .

⇒ | If spark is not observed, refer to Electronic Ignition (EI) System Diagnosis.

8. With the ignition ON and the engine OFF, test the fuses that are supplied by the ignition main relay for voltage. The test lamp should illuminate at each test point for the following fuses:

• | F9

• | F10

• | F47

⇒ | If the test lamp does not illuminate on at least one side of each fuse, refer to LINK.

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

9. 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 Pump Electrical Circuit Diagnosis.

10. Turn OFF the ignition.
11. Install the CH-48027 Digital Pressure Gage or CH-48027 Digital Pressure Gage . Turn ON the ignition and command the fuel pump ON while observing the CH-48027 Digital Pressure Gage or CH-48027 Digital Pressure Gage . The fuel pressure should be between 384-425 kPa (56-62 PSI).

⇒ | If the fuel pressure is not within 384-425 kPa (56-62 PSI), refer to Fuel System Diagnosis.

12. 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 plug. Refer to Spark Plug Inspection.

• | Test the exhaust system for restrictions. Refer to Restricted Exhaust.

### Repair Verification

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Spark Plug Replacement.