Control Module: Testing and Inspection
Transmission Control Module Voltage Supply, Checking
• The Transmission Control Module (TCM) (J217) is a component of the Mechatronic unit in the transmission and cannot be serviced individually.
Special tools, testers and auxiliary items required
• Multimeter.
• Wiring diagram.
Requirements
• The Transmission Control Module (TCM) (J217) fuses OK.
• The battery voltage must be at least 12.5 volts.
• The Ground (GND) connections at the transmission OK.
• The parking brake engaged.
• The selector lever of automatic transmission in position "P".
• All electrical consumers switched off.
• The ignition switched off.
Test sequence
- Disconnect the Transmission Control Module (TCM) (J217) electrical harness connector - direction of the arrow -.
- Check the electrical harness connector for damage, contact corrosion, or ingress of water.
If the electrical harness connector is not OK:
- Repair the malfunction.
If the electrical harness connector is OK:
Checking voltage
- Switch the ignition on.
- Using a Multimeter, check the Power Supply Relay (terminal 15) (J329) socket 2/87 to Ground (GND).
Specified value: battery voltage.
- Switch the ignition off.
If the specified value was not obtained:
- Check the wiring from the Power Supply Relay (terminal 15) (J329) socket 2/87 to the Transmission Control Module (TCM) (J217) electrical harness connector terminal 9 for an open circuit or a short circuit.
- If necessary, repair the faulty wiring connection.
If the specified value was obtained:
- Using a Multimeter, check the Transmission Control Module (TCM) (J217) electrical harness connector terminal 14 to Ground (GND).
Specified value: battery voltage.
If the specified value was obtained:
- Check the wiring from the Battery to the Transmission Control Module (TCM) (J217) electrical harness connector terminal 14 for an open circuit or a short circuit.
- If necessary, repair the faulty wiring connection.
If the specified value was obtained:
Checking Ground (GND)
- Using a Multimeter, check the Transmission Control Module (TCM) (J217) electrical harness connector terminals 13 and 16 to Ground (GND) for resistance.
Specified value: 1.5 ohms
If the specification was not obtained:
- Check the wiring for a an open circuit.
- If necessary, repair the faulty wiring connection.
If no malfunction is found in the wiring:
- Replace the Mechatronic unit in the transmission:.
Final procedures
1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.
2. If necessary, erase the Transmission Control Module (TCM) (J217) memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.