Pinpoint Test D : The TCM (Transmission Control Module) Does Not Respond To The Diagnostic Scan Tool

WARNING: This page is about a different car, the 2020 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

Refer to Module Communications Network for schematic and connector information. Refer to Transmission Controls - TR9070 for schematic and connector information.
Normal Operation and Fault Conditions

The TCM communicates on the HS-CAN1.

Possible Sources
- Fuse
- Wiring, terminals and connectors
- TCM
Visual Inspection and Pre-checks
- Verify BJB fuse 19 (20A).

D1 CHECK THE TCM (TRANSMISSION CONTROL MODULE) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: TCM C1750A.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1750A-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to D2

No	VERIFY BJB fuse 19 (20A) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to the Introduction to identify the possible causes of the circuit short.

D2 CHECK THE TCM (TRANSMISSION CONTROL MODULE) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1750A-4	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to D3

No	REPAIR the circuit.

D3 CHECK THE HS-CAN1 (HIGH-SPEED CONTROLLER AREA NETWORK 1) CIRCUITS BETWEEN THE TCM (TRANSMISSION CONTROL MODULE) AND THE GWM (GATEWAY MODULE A) FOR AN OPEN

Disconnect GWM C2431.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1750A-30	Courtesy of FORD MOTOR COMPANY	C2431-18
C1750A-29	Courtesy of FORD MOTOR COMPANY	C2431-17

Are the resistances less than 3 ohms?

Yes

GO to D4

No	REPAIR the circuit in question.

D4 CHECK FOR CORRECT TCM (TRANSMISSION CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the TCM 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 TCM connectors. Make sure they seat and latch correctly.

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

Is the concern still present?

Yes	CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new TCM. REFER to: Transmission Control Module (TCM) .

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.