Operation CHARM: Car repair manuals for everyone.

Starting and Charging: Testing and Inspection




Engine Cranks Slowly

Diagnostic Instructions

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

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

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Reference Information

Schematic Reference

Starting and Charging Schematics [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Starting System Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, measure and record the battery voltage at the C1 battery terminals.

2. Verify the measured voltage is between 12.0-15.0 V.

If voltage is less than 12.0 V or greater than 15.0 V
Refer to Battery Inspection/Test Battery Inspection/Test.

If voltage is between 12.0-15.0 V

3. Remove the drive belts. Refer to Drive Belt Replacement Service and Repair.

4. Verify the engine cranks slowly when attempting to start the vehicle.

If the engine cranks at normal speed
Inspect the engine and belt drive system for mechanical binding, seized engine, or seized generator.

If the engine cranks slowly

5. Verify that a test lamp illuminates between the M64 starter motor B+ terminal A X2 and ground.

If the test lamp does not illuminate

1. Ignition OFF.

2. Test for less than 2 ohms in the B+ circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.

If the test lamp illuminates

6. Test for less than 0.5 V between the positive battery cable and terminal A X2 at the M64 starter motor with the ignition in the START position.

If 0.5 V or greater
Replace the positive battery cable.

If less than 0.5 V

7. Test for less than 0.5 V between the negative battery cable and the M64 starter motor case with the ignition in the START position.

If 0.5 V or greater
Replace the negative battery cable.

If less than 0.5 V

8. Replace the M64 starter motor.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Battery Positive and Negative Cable Replacement (LFX) Service and Repair

* Battery Negative Cable Replacement Battery Negative Cable Replacement

* Starter Replacement (LFX) Service and Repair