Starter Solenoid Does Not Click

 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.
 Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
B+

 1

 1

 -

 -
Signal

 2

 1

 -

 -
Relay Coil Control Terminal 85

 -

 1

 3

 -
Starter Control Terminal 87

 1

 1

 3

 -
Ground

 -

 1

 -

 -
1. Starter Solenoid Does Not Click

2. Cranks In Any Gear

3. Cranks All The Time


 Circuit/System Description

When the ignition switch is placed in the START position, a discrete signal is supplied to the body control module (BCM) notifying it that the ignition is in the START position. The BCM then sends a serial data message to the engine control module (ECM) that crank has been requested. The ECM then verifies that the clutch pedal is fully depressed or the automatic transmission is in Park/Neutral. If it is, the ECM then supplies 12 V to the control circuit of the starter motor relay. When this occurs, battery voltage is supplied through the switch of the starter relay to the starter solenoid.

 Reference Information

 Schematic Reference


• Starting and Charging Schematics

• Automatic Transmission Controls Schematics for the M36 transmission
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 ON, verify that no starter relay, brake pedal position sensor, immobilizer, or automatic transmission DTCs are set that would cause the ECM to disable engine starting.
2. If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
3. Ignition ON, observe the scan tool BCM Push Button Ignition Switch parameter. Place the ignition switch in the crank position, the parameter should display Crank Request.
4. If not the specified value, refer to Power Mode Mismatch.
5. Transmission range selector in park , verify the scan tool Transmission Range Switch parameters display Park.
6. If the Transmission Range Switch parameter does not indicate Park. Refer to Range Selector Lever Cable Adjustment.
7. Transmission in park or neutral, attempt to start the vehicle. The crank relay should click and the engine should begin cranking.
8. If the KR27 Starter Relay does not click or the engine does not crank, refer to Circuit/System Testing.
 Circuit/System Testing


1. Ignition OFF, disconnect the KR27 Starter Relay.

2. Ignition OFF and scan tool disconnected, open and close the driver door. Wait 1 minute. Test for less than 5 Ω between the relay ground circuit terminal 86 and ground.

3. If greater than the specified range, test the ground circuit for an open/high resistance.

4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground.
6. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.
7. If the test lamp illuminates, test the control circuit for a short to voltage.
8. Parking brake applied and the transmission is in Neutral or Park. Momentarily install a 30 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the starter is activated.
9. Ignition OFF, connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86.
10. Transmission in park or neutral, brake pedal applied, Ignition button pressed. The test lamp should turn ON. After pressing the ignition button again, the test lamp should turn OFF.

11. If the test lamp is always ON, test the control circuit for short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
12. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
13. If all circuits tests normal, replace the KR27 Starter Relay.
 Component Testing


Relay Test

1. Ignition OFF, disconnect the KR27 Starter Relay.
2. Test for 60-180 Ω between terminals 85 and 86.
3. If not within the specified range, replace the KR27 Starter Relay.
4. Test for infinite resistance between the following terminals:
• 30 and 86
• 30 and 87
• 30 and 85
• 85 and 87
5. If not the specified value, replace the KR27 Starter Relay.
6. Install a 20 A fused jumper wire between KR27 Starter Relay terminal 85 and 12 V. Install a jumper wire between KR27 Starter Relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.
7. If greater than specified range, replace the KR27 Starter Relay.
 Repair Instructions

 Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Manual Shift Auxiliary Position Switch Replacement - Steering Wheel

• Relay Replacement (Attached to Wire Harness)

• Control Module References for ECM replacement, setup, and programming