Pinpoint Test T: DTCs U0151:87 And 88
Anti-Lock Control - Hybrid
Pinpoint Tests
Pinpoint Test T: DTCs U0151:87 and 88
Refer to Wiring Diagram Set 42 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The stability/traction control system sensors consist of the yaw rate sensor, roll rate sensor, lateral accelerometer and longitudinal accelerometer. The stability/traction control system sensors are contained within the Restraints Control Module (RCM). The RCM provides the ABS module with the sensor information along a dedicated Controller Area Network 2 (CAN2) bus.
The stability/traction control system sensors are not serviceable separately from the RCM. If a new sensor/accelerometer is needed, a new RCM must be installed.
- DTC U0151:87 Lost Communication With Restraints Control Module: Missing Message - This DTC can set as a result of a loss of communication with the RCM over either the High Speed Controller Area Network (HS-CAN) bus or the CAN2 bus.
- DTC U0151:88 Lost Communication With Restraints Control Module: Bus Off - This DTC can set if either of the CAN2 circuits VCA23 (BU/WH) or VCA24 (GN/OG) are open, shorted to ground, or shorted to each other. Other DTCs indicating missing messages or invalid signal from the Electronic Stability Control (ESC) sensors can set as a result of a CAN2 bus fault.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RCM
PINPOINT TEST T: DTCs U0151:87 and 88
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
NOTE: The stability/traction control system sensors are not serviceable separately from the RCM. If a new sensor is needed, a new RCM must be installed.
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T1 CHECK FOR A HS-CAN COMMUNICATION CONCERN RCM
- Connect the scan tool.
- Ignition ON.
- Using the scan tool, carry out the Network Test.
- Will the RCM pass the Network Test?
Yes
GO to T2.
No
REFER to Information Bus to diagnose the HS-CAN bus.
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T2 CHECK THE CAN2 CIRCUITS FOR AN OPEN
- Ignition OFF.
- Depower the Supplemental Restraint System (SRS). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Air Bag Systems.
- Disconnect: ABS Module C155.
- Disconnect: RCM C2041A and C2041B.
- Measure the resistance between the ABS module, harness side and the RCM, harness side as indicated in the following chart:
- Are the resistances less than 5 ohms?
Yes
GO to T3.
No
REPAIR the affected circuits. CLEAR the DTCs. REPEAT the self-test.
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T3 CHECK THE CAN2 CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between ABS module C155-18, circuit VCA23 (BU/WH), harness side and ABS module C155-19, circuit VCA24 (GN/OG), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to T4.
No
REPAIR the affected circuits. CLEAR the DTCs. REPEAT the self-test.
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T4 CHECK THE CAN2 CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between ground and:
- ABS module C155-18, circuit VCA23 (WH/BU), harness side.
- ABS module C155-19, circuit VCA24 (GN/OG), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to T5.
No
REPAIR the affected circuits. CLEAR the DTCs. REPEAT the self-test.
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T5 CHECK THE CAN2 CIRCUITS FOR A SHORT TO VOLTAGE
- Measure the voltage between ground and:
- ABS module C155-18, circuit VCA23 (WH/BU), harness side.
- ABS module C155-19, circuit VCA24 (GN/OG), harness side.
- Is any voltage present?
Yes
REPAIR the affected circuits. CLEAR the DTCs. REPEAT the self-test.
No
GO to T6.
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T6 CHECK FOR ADDITIONAL SRS DTCs
- 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.
- Reconnect all SRS components (if previously disconnected).
- If previously directed to depower the SRS, repower the SRS. Do notprove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Air Bag Systems.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - Clear all CMDTCs.
- Enter the following diagnostic mode on the scan tool: Self Test - ABS Module.
- Are DTCs U0151:87 and/or U0151:88 present?
Yes
INSTALL a new RCM.
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.
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