Pinpoint Test J: DTC U0151:88
Anti-Lock Control
Pinpoint Test J: DTC U0151:88
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The Restraints Control Module (RCM) measures vehicle yaw rate, lateral acceleration and longitudinal acceleration and then sends the information to the ABS module along a dedicated pair of Controller Area Network (CAN) circuits. This dedicated CAN is used only for communication between the RCM and the ABS module. The yaw rate sensor, lateral accelerometer and longitudinal accelerometer are contained in the RCM.
- DTC U0151:88 (Lost Communication With Restraints Control Module: Bus Off) - This DTC can set if either of the dedicated CAN circuits are open, shorted to ground or shorted to each other. Other DTCs indicating missing messages or invalid signals from the RCM sensors can set as a result of a dedicated CAN fault.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RCM
- ABS module
PINPOINT TEST J: DTC U0151:88
WARNING: Never probe the electrical connectors on air bag, Safety Canopy(R) or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
-------------------------------------------------
J1 CHECK FOR AN HS-CAN CONCERN WITH THE RCM
- Connect the scan tool.
- Ignition ON.
- NOTE: The Network Test does not test the dedicated CAN communications between the ABS module and RCM.
- Using the scan tool, carry out the Network Test.
- Does the RCM pass the Network Test?
Yes
GO to J2.
No
REFER to Module Communications Network Testing and Inspection to diagnose the RCM does not respond to scan tool.
-------------------------------------------------
J2 CHECK FOR CORRECT RCM
- Ignition OFF.
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Gain access to the RCM and check the part number on the RCM against the part number listed in the Ford Catalog Advantage(TM) or equivalent. Refer to Supplemental Restraint System Service and Repair.
- Does the part number on the RCM match the part number listed in the Ford Catalog Advantage(TM) or equivalent?
Yes
GO to J3.
No
INSTALL the correct RCM. REFER to Supplemental Restraint System Service and Repair. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
J3 CHECK THE DEDICATED CAN CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: ABS Module C135 .
- Disconnect: RCM C310B .
- Ignition ON.
- Measure the voltage between ground and:
- ABS module C135-19, circuit VCA24 (GN/OG), harness side.
- ABS module C135-18, circuit VCA23 (BU/WH), harness side.
- Is any voltage present?
Yes
REPAIR the affected circuit(s) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to J4.
-------------------------------------------------
J4 CHECK THE DEDICATED CAN CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between ground and:
- ABS module C135-19, circuit VCA24 (GN/OG), harness side.
- ABS module C135-18, circuit VCA23 (BU/WH), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
GO to J5.
No
REPAIR the affected circuit(s). TEST the system for normal operation.
-------------------------------------------------
J5 CHECK THE DEDICATED CAN CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between ABS module C135-19, circuit VCA24 (GN/OG), harness side and ABS module C135-18, circuit VCA23 (BU/WH), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
GO to J6.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
J6 CHECK THE DEDICATED CAN CIRCUITS FOR AN OPEN
- Measure the resistance between the ABS module C135, harness side and the RCM C310B, harness side as indicated in the following chart:
- Are the resistances less than 5 ohms?
Yes
GO to J7.
No
REPAIR the affected circuit(s). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.
-------------------------------------------------
J7 CHECK FOR CORRECT RCM OPERATION
- Disconnect: RCM C310B.
- Check for:
- corrosion
- pushed-out pins
- spread terminals
- Connect: RCM C310B.
- Make sure the connector is seated correctly, then operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new RCM. REFER to Supplemental Restraint System Service and Repair. CLEAR the DTCs. REPEAT the self-test. If DTC U0151:88 Is retrieved again GO to J8
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 self-test.
-------------------------------------------------
J8 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect: ABS module C135.
- Check for:
- corrosion
- pushed-out pins
- spread terminals
- Connect: ABS module C135.
- Make sure the connector is seated correctly, then operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new ABS module. REFER to Hydraulic Control Unit (HCU) Service and Repair. TEST the system for normal operation.
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 self-test.
-------------------------------------------------