Chevrolet Trax: Engine cranks but does not run

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 conditions listed below:

• 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 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.
• An engine 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 (Encore) , Engine Controls Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

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

• CH 48027 Digital Pressure Gauge
• EL 26792 HEI Spark Tester
• EN 36012-A Ignition System Diagnostic Harness

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Circuit/System Verification

NOTE:

This diagnostic assumes the following:

• The battery is completely charged.
• The engine cranking speed is acceptable.

An engine that starts and stalls is considered to not run.

1. Crank the engine for up to 15 s.
2. Verify that DTC P0006, P0007, P2666, or P2667, P0117, P0118, P0122, P0123, P01A8 or P01A9, P0222, P0223, P0335, P0336, P0513, P0562, P0563, P0601, P0602, P0603, P0604, P0606, P062F, P0633, P0685, P0689, P0690, P1516, P15AC, P15AE or P15AF, P1631, P1682, P16F3, P2101, P2119, P25A6, or P2610 is not set.

• If any of DTCs are set .

Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

• If none of the DTCs are set

3. Ignition ON.
4. Verify that the immobilizer system indicator on the instrument cluster illuminates momentarily.

• If the indicator stays ON or is flashing

Review the Diagnostic Trouble Code (DTC) List - Vehicle , for immobilizer system DTCs. For more information concerning the immobilizer system, refer to Immobilizer Description and Operation .

• If the indicator does not stay ON and is not flashing

5. Verify the scan tool Engine Speed parameter displays greater than 0 RPM, while cranking the engine.

• If 0 RPM

Refer to DTC P0335 or P0336.

• If greater than 0 RPM

NOTE: It may be necessary to secure the EN 36012-A ignition system diagnostic harness to the spark plug boots with electrical tape.

6. Connect the EN 36012-A ignition system diagnostic harness to the spark plug boots.
7. Connect the EL 26792 HEI spark tester between the boot of a spark plug wire and ground.
8. Connect the remaining wires to the appropriate cylinders.

NOTE: An erratic or weak spark is considered a no spark condition.

9. Verify the spark tester sparks, while cranking the engine.

• If the spark tester does not spark

Refer to Electronic Ignition System Diagnosis

• If the spark tester sparks

10. Verify correct operation of the fuel system-Perform the Fuel System Diagnosis (LUJ), Fuel System Diagnosis (LUV).

• If the fuel system does not operate correctly

Repair as necessary.

• If the fuel system operates correctly

11. Verify the conditions listed below do not exist:

• A collapsed air intake duct to the throttle body
• A restricted air filter or air intake system
• Coolant or gas fouled spark plugs
• A skewed manifold absolute pressure (MAP) sensor
• A skewed engine coolant temperature (ECT) sensor
• A restricted exhaust system. Refer to Restricted Exhaust .
• Contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis.
• An engine mechanical condition, for example, worn timing chain and gears or low compression- Refer to Symptoms - Engine Mechanical .
• If a condition exists

Repair as necessary.

• If no condition exists

12. All OK

Repair Verification

Perform the Diagnostic Repair Verification after completing the repair.

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