Pinpoint Test C : The BCM Does Not Respond To The Scan Tool
WARNING: This page is about a different car, the 2018 Lincoln MKT. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Failure to disconnect the battery when instructed results in false resistance readings. Refer to Battery, Mounting and Cables
.
- C1 CHECK THE HS-CAN TERMINATION RESISTANCE
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect the scan tool cable from the Data Link Connector (DLC).
- Measure the resistance
between:
Positive Lead Negative Lead Pin Circuit Pin Circuit C251-6 VDB04 (WH/BU) C251-14 VDB05 (WH)
Is the resistance between 54 and 66 ohms?
Yes GO to C3. No GO to C2. - C2 CHECK THE HS-CAN CIRCUITS BETWEEN THE BCM AND THE DLC FOR AN OPEN
- Disconnect: BCM C2280F .
- Measure the resistance
between:
Positive Lead Negative Lead Pin Circuit Pin Circuit C2280F-16 VDB04 (WH/BU) C251-6 VDB04 (WH/BU) C2280F-17 VDB05 (WH) C251-14 VDB05 (WH)
Are the resistances less than 3 ohms?
Yes GO to C7. No REPAIR the circuit in question. - C3 CHECK THE MS-CAN TERMINATION RESISTANCE
- Measure the resistance
between:
Positive Lead Negative Lead Pin Circuit Pin Circuit C251-3 VDB06 (GY/OG) C251-11 VDB07 (VT/OG)
Is the resistance between 54 and 66 ohms?
Yes GO to C5. No GO to C4. - Measure the resistance
between:
- C4 CHECK THE MS-CAN CIRCUITS BETWEEN THE BCM AND THE DLC FOR AN OPEN
- Disconnect: BCM C2280B .
- Measure the resistance
between:
Positive Lead Negative Lead Pin Circuit Pin Circuit C2280B-38 VDB06 (GY/OG) C251-3 VDB06 (GY/OG) C2280B-39 VDB07 (VT/OG) C251-11 VDB07 (VT/OG)
Are the resistances less than 3 ohms?
Yes GO to C7. No REPAIR the circuit in question. - C5 CHECK THE BCM VOLTAGE SUPPLY CIRCUIT FOR AN OPENNOTE: Measurements are taken with the fuse installed and probes placed at the terminals on the back of the fuse blade.
- Ignition ON.
- Disconnect: BCM C2280G .
- Connect: Negative Battery Cable.
- Measure the voltage
between:
Positive Lead Negative Lead Pin Circuit Pin Circuit C2280G-1 SBF01 (RD) - Ground
Is the voltage greater than 11 volts?
Yes GO to C6. No VERIFY the high current BJB fuse 1 (100A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short. - C6 CHECK THE BCM GROUND CIRCUIT FOR AN OPEN
- Disconnect: BCM C2280D .
- Measure the resistance
between:
Positive Lead Negative Lead Pin Circuit Pin Circuit C2280D-25 GD233 (BK) - Ground
Is the resistance less than 3 ohms?
Yes GO to C7. No REPAIR the circuit in question. - C7 CHECK FOR CORRECT BCM OPERATION
- Disconnect all the BCM connectors.
- Repair:
- corrosion (replace connector or terminals - clean module pins)
- damaged or bent pins - replace terminals/pins
- pushed-out pins - replace pins as necessary
- Connect all the BCM connectors and make sure they are seated correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, discontinue this test and follow TSB instructions. If no TSBs address this concern, refer to BCM HARDWARE TESTING . No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.