Starter Solenoid Does Not Click LS4

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 message to the engine control module (ECM) that crank has been requested. The ECM then verifies that the transmission is in Park or Neutral. If it is, the ECM then supplies a ground to the control circuit of the STARTER relay. When this occurs, battery voltage is supplied through the switch of the STARTER relay to the starter solenoid.

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Starting System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, verify that no starter relay, theft deterrent, or automatic transmission DTCs are set that would cause the ECM to disable starting.

⇒	If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

2. Ignition ON, observe the scan tool BCM Starter Switch parameter. Place ignition switch in the crank position, the parameter should display ON.

⇒	If not the specified value, refer to Power Mode Mismatch .

3. Transmission range selector in park , verify the scan tool ECM PNP Switch and TCM IMS parameters display Park/Neutral.

⇒	If the TCM IMS parameter does not indicate Park/Neutral, refer to Transmission Internal Mode Switch Logic

⇒	If the ECM Park/Neutral parameter does not indicate Park/Neutral, refer to ECM Park Switch Circuit Malfunction.

4. Transmission range selector in park or neutral, attempt to start the vehicle. The starter relay should click and the engine should begin cranking.

⇒	If the starter relay does not click or the engine does not crank, refer to Starter Relay Circuit Malfunction.

ECM Park Switch Circuit Malfunction (4T65-E)

1. Ignition OFF, disconnect the harness connector at the AT inline 20-Way connector.
2. Ignition ON, install a 3A fused jumper wire between the signal circuit terminal W and ground. Verify the scan tool ECM PNP switch parameter displays Park/Neutral.

⇒	If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. If all circuits test normal, test or replace the internal mode switch (IMS).

Starter Relay Circuit Malfunction

1. Ignition OFF, disconnect the starter relay.
2. Ignition ON, verify a test lamp illuminates between the relay coil B+ circuit terminal 85 and ground.

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

3. Ignition ON, verify a test lamp illuminates between the relay switch B+ circuit terminal  30 and ground.

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

4. Connect a test lamp between the relay coil control circuit terminal  86 and the relay coil B+ circuit terminal  85.
5. With the transmission range selector in park or neutral, cycle the ignition between the OFF and CRANK position. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

6. Ensure the parking brake is applied and the transmission is in PARK.
7. Momentarily install a 40A fused jumper wire between the B+ circuit terminal 30 and the control output circuit terminal 87.
8. The starter solenoid should engage and the engine should begin cranking.

⇒	If the solenoid does not engage, test the control output circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the starter motor.

9. If all circuits test normal, test or replace the starter relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Starter Solenoid Does Not Click L26/L32

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 message to the powertrain control module (PCM) that crank has been requested. The PCM then verifies that the transmission is in Park or Neutral. If it is, the PCM then supplies a ground to the control circuit of the CRANK relay. When this occurs, battery voltage is supplied through the switch of the CRANK relay to the starter solenoid.

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

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, verify that no starter relay, theft deterrent, or automatic transmission DTCs are set that would cause the PCM not to enable engine starting.

⇒	If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle

2. Ignition ON, observe the scan tool BCM Starter Switch parameter. Place ignition switch in the crank position, the parameter should display ON.

⇒	If not the specified value, refer to Power Mode Mismatch .

3. Transmission range selector in park , verify the scan tool PCM IMS parameters display Park/Neutral.

⇒	If the PCM IMS parameter does not indicate Park/Neutral, refer to Range Selector Displays Incorrect Range

4. Transmission range selector in park or neutral, attempt to start the vehicle. The crank relay should click and the engine should begin cranking.

⇒	If the crank relay does not click or the engine does not crank, refer to Crank Relay Circuit Malfunction.

Crank Relay Circuit Malfunction

1. Ignition OFF, disconnect the crank relay.
2. Ignition ON, verify a test lamp illuminates between the relay coil B+ circuit terminal M4 and ground.

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

3. Ignition ON, verify a test lamp illuminates between the relay switch B+ circuit terminal K4 and ground.

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

4. Connect a test lamp between the relay coil control circuit terminal K5 and the relay coil B+ circuit terminal M4.
5. With the transmission range selector in park or neutral, cycle the ignition between the OFF and CRANK position. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the PCM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.

6. Ensure the parking brake is applied and the transmission is in PARK.
7. Momentarily install a 40A fused jumper wire between the B+ circuit terminal K4 and the control output circuit terminal M5.
8. The starter solenoid should engage and the engine should begin cranking.

⇒	If the solenoid does not engage, test the control output circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the starter motor.

9. If all circuits test normal, test or replace the crank relay.

1. Ignition OFF, disconnect the crank relay.
2. Test for 60-180  ohms between terminals 85 and 86.

⇒	If the resistance is not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified value, replace the relay.

4. Install a 20A fused jumper wire between terminal 85 and 12 volts. Install a jumper wire between terminal 86 and ground. Test for less than 2.0 ohms of resistance between terminals 30 and 87.

⇒	If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.