Diagnostic Routine AB

Diagnostic Routine AB

Diagnostic Overview

The Transmission Control Module (TCM) Does Not Respond To The Scan Tool

Refer to Wiring Diagram Set 14 for schematic and connector information Electrical Diagrams.

Refer to Wiring Diagram Set 29 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The TCM (Transmission Control Module) communicates with the scan tool through the HS-CAN (High Speed Controller Area Network).

Visual Inspection and Diagnostic Pre-checks

Verify BJB (Battery Junction Box) fuses 38 (15A), 15 (25A) and 26 (15A) are OK.

Pinpoint Test

1. CHECK THE TCM (Transmission Control Module) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: TCM (Transmission Control Module) C1750A.

3. Ignition ON.

4. Measure:





Are the voltages greater than 11 volts?






2. CHECK THE TCM (Transmission Control Module) GROUND CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Measure:





Are the resistances less than 3 ohms?






3. CHECK THE HS-CAN (High Speed Controller Area Network) CIRCUITS BETWEEN THE TCM (Transmission Control Module) AND THE DLC (Data Link Connector) FOR AN OPEN

1. Measure:





Are the resistances less than 3 ohms?






4. CHECK FOR CORRECT TCM (Transmission Control Module) OPERATION

1. Ignition OFF.

2. Disconnect and inspect all the TCM (Transmission Control Module) connectors.

3. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

4. Reconnect the TCM (Transmission Control Module) connectors. Make sure they seat and latch correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?