Starter Solenoid Does Not Click
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Starter Solenoid Does Not Click
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Diagnostic Fault Information
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Circuit
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Short to Ground
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Open/High Resistance
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Short to Voltage
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Signal Performance
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B+
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1
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1
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-
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-
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Signal
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2
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1
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-
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-
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Relay Coil Control Terminal 85
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-
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1
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3
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-
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Starter Control Terminal 87
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1
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1
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3
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-
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Ground
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-
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1
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-
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-
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1. Starter Solenoid Does Not Click
2. Cranks In Any Gear
3. Cranks All The Time
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Circuit/System Description
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When the ignition mode 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 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 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
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Circuit/System Verification
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1.
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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.
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3.
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Ignition ON, observe the scan tool BCM 5 V Ignition Switch parameter. Place the ignition switch in the crank position, the parameter should display Crank Request.
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5.
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Transmission range selector in park , verify the scan tool TCM Internal Mode Switch parameters display Park.
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7.
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Transmission in park or neutral, attempt to start the vehicle. The crank relay should click and the engine should begin cranking.
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8.
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If the KR27 starter relay does not click or the engine does not crank, refer to Circuit/System Testing.
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1.
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Ignition OFF, disconnect the KR27 starter relay.
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2.
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Ignition OFF and scan tool disconnected, open and close the driver door. Wait 1 minute. Test for less than 5.0 Ω between the relay ground circuit terminal 86 and ground.
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3.
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If greater than the specified range, test the ground circuit for an open/high resistance.
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4.
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Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 30 and ground. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground.
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5.
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If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
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6.
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Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.
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7.
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If the test lamp illuminates, test the control circuit terminal 87 for a short to voltage.
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8.
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Ensure the parking brake is applied and the T12 transmission is in PARK. Momentarily install a 30 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the M64 starter motor is activated.
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9.
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If the M64 starter motor does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the M64 starter motor.
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10.
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Connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86.
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11.
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Transmission in park/neutral, command the starter relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
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12.
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If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
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13.
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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 ECM.
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14.
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If all circuits test normal, test or replace the KR27 starter relay.
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Relay Test
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1.
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Ignition OFF, disconnect the KR27 starter relay.
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2.
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Test for 60-180 Ω between terminals 85 and 86.
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3.
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If not within the specified range, replace the relay.
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4.
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Test for infinite resistance between the following terminals:
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5.
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If not the specified value, replace the relay.
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6.
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Install a 20 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.
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7.
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If greater than the specified range, replace the relay.
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Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
