Pinpoint Test Ai: The TELEMATIC Control Unit (TCU) Module Does Not Respond To The Diagnostic Scan Tool

WARNING: This page is about a different variant/trim than selected.

AI1 CHECK THE TCU (TELEMATIC CONTROL UNIT MODULE) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Ignition OFF.
Disconnect: TCU C4803 .
Ignition ON.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C4803-1		Ground

Is the voltage greater than 11 volts?

Yes : GO to AI2
No : VERIFY BCM fuse 10 (5A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM WIRING DIAGRAMS -- (EXCEPT HYBRID) to identify the possible causes of the circuit short.

AI2 CHECK THE TCU (TELEMATIC CONTROL UNIT MODULE) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement/Action	Negative Lead
C4803-13		Ground

Is the resistance less than 3 ohms?

Yes : GO to AI3
No : REPAIR the circuit.

AI3 CHECK THE HS-CAN3 (HIGH SPEED-CONTROLLER AREA NETWORK 3) CIRCUITS BETWEEN THE TCU (TELEMATIC CONTROL UNIT MODULE) AND THE GWM (GATEWAY MODULE A) FOR AN OPEN

Disconnect: GWM C2431 .

Measure:

Positive Lead	Measurement/Action	Negative Lead
C4803-8		C2431-16
C4803-16		C2431-15

Are the resistances less than 3 ohms?

Yes : GO to AI4
No : REPAIR the circuit in question.

AI4 CHECK FOR CORRECT TCU (TELEMATIC CONTROL UNIT MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect the TCU connectors.
- 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
- Reconnect the TCU connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
1. Yes : CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new TCU.
2. No : The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.