Pinpoint Test T: The Transmission Control Module (TCM) Does Not Respond To The Scan Tool
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
- T1 CHECK THE POWER TO THE TCM
- Key in OFF position.
- Disconnect: TCM C1458a
- Key in ON position.
- Measure the voltage between the TCM harness side and ground as follows:
Connector-Pin Circuit C1458a-4 1865 (WH/OG) C1458a-5 1865 (WH/OG) C1458a-12 69 (RD/LG) - Are the voltages greater than 10 volts?
- YES : Go to T2.
- NO : VERIFY the battery junction box (BJB) fuse 8 (10A) or fuse 3 (5A) is OK. If OK, REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
- T2 CHECK THE TBCM GROUNDS
- Key in OFF position.
- Measure the resistance between the TCM harness side and ground as follows:
Connector-Pin Circuit C1458a-2 57 (BK) C1458a-8 57 (BK) - Are the resistances less than 5 ohms?
- YES : Go to T3.
- NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.
- T3 CHECK THE HS-CAN CIRCUITS BETWEEN THE TCM AND THE DATA LINK CONNECTOR (DLC) FOR AN OPEN
- Measure the resistance between the TCM C1458a-1, circuit 1908 (WH), harness side and the DLC C251-6, circuit 1908 (WH), harness side; and between the TCM C1458a-7, circuit 1909 (BK), harness side and the DLC C251-14, circuit 1909 (BK), harness side.
- Are the resistances less than 5 ohms?
- YES : Go to T4.
- NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
- T4 CHECK FOR CORRECT TCM OPERATION
- Disconnect the TCM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the TCM connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- YES : INSTALL a TCM. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - ELECTRONICALLY CONTROLLED CONTINUOUSLY VARIABLE TRANSMISSION (ECVT) article. CLEAR the DTCs. REPEAT the network test with the scan tool.
- NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.