Engine Cranks Slowly

 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.


 Reference Information

Schematic Reference

Starting and Charging Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Starting System Description and Operation

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

 Circuit/System Verification


1. Ignition OFF, measure and record the battery voltage at the C1 terminals. The voltage should be between 12.0-15.0 V.

2. If not within the specified range, refer to Battery Inspection/Test.

3. Remove the drive belts. Refer to one of the following:

Drive Belt Replacement for the 2.0L engine

Drive Belt Tensioner Replacement for the 2.0L engine

Drive Belt Replacement for the 2.0L (Diesel) engine

Drive Belt Tensioner Replacement for the 2.0L (Diesel) engine

Drive Belt Tensioner Replacement for the 2.8L, 3.0L, 3.2L, or 3.6L engine

Drive Belt Replacement for the 2.8L, 3.0L, 3.2L, or 3.6L engine

4. Ignition ON, attempt to start the engine. Make sure the crankshaft is rotating normally.

5. If the engine cranks normal, inspect the engine and belt drive system for mechanical binding, seized engine, or seized generator.

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

7. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

8. Test for less than 0.5 V between the positive battery cable and terminal A X2 at the M64 starter motor as ignition is switched to start position.

9. If greater than the specified value, replace the positive battery cable.

10. Test for less than 0.5 V between the negative battery cable and the M64 Starter Motor case as ignition is switched to start position.

11. If greater than the specified value, replace the negative battery cable.

12. If all circuits test normal, replace the M64 Starter Motor.


 Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


Battery Positive Cable Replacement

Battery Negative Cable Replacement (Gasoline)

Starter Replacement (2.0L Diesel) Starter Replacement (LAU/A28NER) Starter Replacement (LDE/A16XER, LLU/A16LET, 2H0/A18XER) Starter Replacement (LHU/A20NFT)