Pinpoint Test I: The Traction Battery Control Module (TBCM) Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

I1 CHECK THE POWER TO THE TBCM

WARNING: When servicing the high-voltage system, establish a buffer zone per the specified procedure. Failure to follow this instruction may result in serious personal injury or death.

WARNING: Turn OFF the ignition switch for a minimum of 5 minutes before removing high-voltage cables. High-voltage cables and wiring are orange in color. The nominal high-voltage traction battery voltage (HVTB) is 330 V DC. Failure to follow these instructions may result in serious personal injury or death.

WARNING: Depower the high-voltage traction battery (HVTB) before carrying out any removal or installation procedures affecting the high-voltage battery system. Failure to follow this instruction may result in serious personal injury or death.

WARNING: Wear high-voltage insulated safety gloves and a face shield when working with high-voltage batteries or cables. The high-voltage insulated safety gloves should be of the appropriate safety and protection rating. Inspect the gloves before use and always wear them with the leather outer glove. Any hole in the rubber insulating glove is a potential entry point for high-voltage. Failure to follow these instructions may result in serious personal injury or death.

Key in OFF position.
Disconnect: TBCM C4227a
Key in ON position.

Measure the voltage between the TBCM, harness side and ground as follows:

Connector-Pin	Circuit
C4227a-4	SBB15 (WH/RD)
C4227a-5	SBB15 (WH/RD)
C4227a-6	SBB15 (WH/RD)
C4227a-10	SBB05 (GY/RD)
C4227a-11	SBB05 (GY/RD)
C4227a-19	CBB23 (BN/YE)

Are the voltages greater than 10 volts?

YES : Go to I2.
NO : VERIFY the battery junction box (BJB) fuse 5 (10A), fuse 23 (5A), and fuse 15 (50A) are OK. If OK, REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

I2 CHECK THE TBCM GROUNDS

Key in OFF position.

Measure the resistance between the TBCM, harness side and ground as follows:

Connector-Pin	Circuit
C4227a-30	GD182 (BK/GY)
C4227a-31	GD182 (BK/GY)
C4227a-35	GD149 (BK/GY)
C4227a-36	GD149 (BK/GY)
C4227a-37	GD149 (BK/GY)

Are the resistances less than 5 ohms?

YES : Go to I3.
NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

I3 CHECK THE HS-CAN CIRCUITS BETWEEN THE TBCM AND THE DATA LINK CONNECTOR (DLC) FOR AN OPEN
- Measure the resistance between the TBCM C4227a-29, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side; and between the TBCM C4227a-28, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
- Are the resistances less than 5 ohms?
1. YES : Go to I4.
2. NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
I4 CHECK FOR CORRECT TBCM OPERATION
NOTE: Do not disconnect the high voltage cables or connectors in the following step.
- Disconnect the TBCM connector.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect the TBCM connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new high voltage traction battery. REFER to HIGH VOLTAGE TRACTION BATTERY article. CLEAR the DTCs. REPEAT the network test with the scan tool.
2. 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.