U1901
Anti-Lock Control - Non-Hybrid
Pinpoint Test G: DTCs C1963, C2777, U0151, U0452 and U1901
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. [1][2]Diagrams By Number
Normal Operation
The yaw rate sensor, lateral accelerometer and longitudinal accelerometer are contained in Restraints Control Module (RCM). The RCM (Restraints Control Module) measures vehicle yaw rate, lateral acceleration and longitudinal acceleration and then sends the information to the ABS module along the dedicated Controller Area Network (CAN) bus. This dedicated CAN (Controller Area Network) bus is used only for communication between the RCM (Restraints Control Module) and the ABS module. The information sent to the ABS module is used to help determine if the AdvanceTrac(R) system needs to be activated.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RCM (Restraints Control Module) incorrectly mounted
- RCM (Restraints Control Module)
- ABS module
PINPOINT TEST G : DTCs C1963, C2777, U0151, U0452 AND U1901
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.
WARNING: Never disassemble or tamper with seat belt deployable components, including pretensioners, load limiters and inflators. Never back probe deployable device electrical connectors. Tampering or back probing may cause an accidental deployment and result in 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.
NOTE: Supplemental Restraint System (SRS) components should only be disconnected or reconnected when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS (Supplemental Restraint System).
NOTE: The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.
G1 CHECK FOR AN HS-CAN (High Speed Controller Area Network) CONCERN WITH THE RCM (Restraints Control Module)
- Connect the scan tool.
- Ignition ON.
- NOTE: The Network Test does not test the dedicated CAN (Controller Area Network) communications between the ABS module and RCM (Restraints Control Module).
Using the scan tool, carry out the Network Test.
Does the RCM (Restraints Control Module) pass the Network Test?
Yes
GO to G2.
No
REFER to Information Bus to diagnose the High Speed Controller Area Network (HS-CAN)
concern.
G2 CHECK FOR CORRECT RCM (Restraints Control Module)
- 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 (Restraints Control Module) and check the part number on the RCM (Restraints Control Module) against the part number listed in the master parts catalog. Refer to Restraints and Safety Systems &/or Air Bag Systems.
Does the part number on the RCM (Restraints Control Module) match the part number listed in the master parts catalog?
Yes
GO to G3.
No
INSTALL the correct RCM (Restraints Control Module). REFER to Restraints and Safety Systems &/or Air Bag Systems. GO to G13.
G3 CHECK FOR CORRECT ABS MODULE
- Enter the following diagnostic mode on the scan tool: Log Viewer.
- Retrieve and record the ABS module part number from Log Viewer and check the part number on the ABS module against the part number listed in the master parts catalog.
Does the part number retrieved from the ABS module match the part number listed in the master parts catalog?
Yes
GO to G4.
No
INSTALL the correct ABS module. REFER to Anti-Lock Brake System (ABS) Module . GO to G13.
G4 CHECK THE RCM (Restraints Control Module) CONDITION AND INSTALLATION
- Depower the Supplemental Restraint System (SRS). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Inspect the RCM (Restraints Control Module) for cracks in the case, broken anchor tabs, broken electrical connector and correct installation. Refer to Removal and Installation, Restraints Control Module (RCM) in Restraints and Safety Systems &/or Air Bag Systems.
Is the RCM (Restraints Control Module) installed correctly and undamaged?
Yes
GO to G5.
No
REINSTALL or INSTALL new as necessary. GO to G13.
G5 CHECK THE DEDICATED CAN (Controller Area Network) CIRCUITS FOR AN OPEN
- Disconnect: ABS Module C135.
- Disconnect: RCM (Restraints Control Module) C310B.
- Measure the resistance between the ABS module C135, harness side and the RCM (Restraints Control Module) C310B, harness side as indicated in the following chart:
ABS Module Circuit RCM (Restraints Control Module) C135-18 VCA23 (BU/WH) C310B-20 C135-19 VCA24 (GN/OG) C310B-19
Are the resistances less than 5 ohms?
Yes
GO to G6.
No
REPAIR the affected circuit(s). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test. GO to G13.
G6 CHECK THE DEDICATED CAN (Controller Area Network) 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 G7.
No
REPAIR the affected circuit(s). GO to G13.
G7 CHECK THE DEDICATED CAN (Controller Area Network) 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 G8.
No
REPAIR the affected circuit(s). GO to G13.
G8 CHECK THE DEDICATED CAN (Controller Area Network) CIRCUITS FOR A SHORT TO VOLTAGE
- 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). GO to G13.
No
GO to G9.
G9 CHECK RCM (Restraints Control Module) TERMINATING RESISTOR
- Ignition OFF.
- Connect: RCM (Restraints Control Module) C310B.
- Measure the resistance between ABS module C135-18, circuit VCA23 (BU/WH), harness side and C135-19, circuit VCA24 (GN/OG), harness side.
Is the resistance between 108 and 132 ohms?
Yes
GO to G10.
No
GO to G11.
G10 CHECK THE ABS MODULE FOR CORRECT OPERATION
- Prior to reconnecting any previously disconnected SRS (Supplemental Restraint System) component:
- inspect connector(s) (including any in-line connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- inspect RCM (Restraints Control Module) C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation. Refer to RCM (Restraints Control Module) in Restraints and Safety Systems &/or Air Bag Systems.
- inspect ABS module C135 for dirt, corrosion, water intrusion, pushed out, loose or spread terminals and loose or frayed wire connections at terminals.
- repair any concerns found.
Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. [1][2]Diagrams By Number
- Connect: All Previously Disconnected Component(s)/Connector(s).
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
Do any of the DTCs listed in Normal Operation return?
Yes
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . GO to G13.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. GO to G13.
G11 CONFIRM THE RCM (Restraints Control Module) FAULT
NOTE: Make sure all restraint system components, sensor electrical connectors and the RCM (Restraints Control Module) electrical connectors are connected before carrying out the self-test. If not, DTCs can be recorded.
- If previously directed to repower the SRS (Supplemental Restraint System) , depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Prior to reconnecting any previously disconnected SRS (Supplemental Restraint System) component:
- inspect connector(s) (including any in-line connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- inspect RCM (Restraints Control Module) C310A and C310B CPA (Connector Position Assurance) lever/lock for correct operation. Refer to RCM (Restraints Control Module) Removal and Installation in Restraints and Safety Systems &/or Air Bag Systems.
- inspect ABS module C135 for dirt, corrosion, water intrusion, pushed out, loose or spread terminals and loose or frayed wire connections at terminals.
- repair any concerns found.
Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. [1][2]Diagrams By Number
- Connect: All Previously Disconnected Component(s)/Connector(s).
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Enter the following diagnostic mode on the scan tool: Self Test- RCM (Restraints Control Module).
Were DTCs U0028:08 and/or U0028:88 retrieved on-demand during self-test?
Yes
INSTALL a new RCM (Restraints Control Module). GO to G13.
No
In the process of diagnosing the fault, the fault condition has become intermittent.
CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition frequently. ACTIVATE other systems in the same wire harness. Do not install any new SRS (Supplemental Restraint System) components at this time. SRS (Supplemental Restraint System) components should only be installed when directed to do so in the pinpoint test. GO to G12.
G12 CHECK FOR AN INTERMITTENT FAULT
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Disconnect RCM (Restraints Control Module) C310B and ABS module C135:
- inspect connector(s) (including any in-line connectors) for corrosion, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- repair any concerns found.
Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. [1][2]Diagrams By Number
- Connect: All Previously Disconnected Component(s)/Connector(s).
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- RCM (Restraints Control Module).
Are any RCM (Restraints Control Module) DTCs retrieved on-demand during the self-test?
Yes
REFER to Diagnosis and Testing in Restraints and Safety Systems &/or Air Bag Systems. Testing and Inspection
No
The fault is not present and cannot be recreated at this time. Do not install any new SRS (Supplemental Restraint System) components at this time. SRS (Supplemental Restraint System) components should only be installed when directed to do so in the pinpoint test. GO to G13.
G13 CHECK FOR ADDITIONAL RCM (Restraints Control Module) AND ABS MODULE 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 (Supplemental Restraint System) components (if previously disconnected).
- If previously directed to depower the SRS (Supplemental Restraint System) , repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- RCM (Restraints Control Module).
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
Were any DTCs retrieved on-demand from the RCM (Restraints Control Module) or ABS module during self-test?
Yes
Do not clear any DTCs until all DTCs have been resolved. GO to the appropriate DTC Chart and/or Restraints and Safety Systems &/or Air Bag Systems for pinpoint test direction.
No
CLEAR all Continuous Memory Diagnostic Trouble Codes (CMDTCs). PROVE OUT the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems. Repair is complete. RETURN the vehicle to the customer.