Captiva |
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• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
B+ | 1 | 1 | - | - |
Signal | 2 | 1 | - | - |
Relay Coil Control Terminal 86 | - | 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 |
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.
• | Automatic Transmission Controls Schematics for the 6T30/6T40/6T45/6T50 gearbox |
Starting System Description and Operation
Control Module References for scan tool information
⇒ | If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle . |
⇒ | If not the specified value, refer to Power Mode Mismatch . |
⇒ | If the TCM Internal Mode Switch parameter does not indicate Park. Refer to Transmission Internal Mode Switch Logic . |
⇒ | If the starter relay does not click or the engine does not crank, refer to Circuit/System Testing. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | 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 or starter fuse is open, test the control circuit terminal 87 for a short to ground. |
⇒ | If the test lamp illuminates, test the control circuit terminal 87 for a short-circuit to voltage. |
⇒ | 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. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | 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 ECM. |
⇒ | If not within the specified range, replace the relay. |
• | 30 and 86 |
• | 30 and 87 |
• | 30 and 85 |
• | 85 and 87 |
⇒ | If not the specified value, replace the relay. |
⇒ | If greater than specified range, replace the relay. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Relay Replacement : Within an Electrical Center → Attached to Wire Harness |
• | Control Module References for ECM replacement, setup, and programming |
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