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Home >> Ford Truck >> 2012 >> Explorer FWD L4-2.0L Turbo >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> U Code Charts >> U0028 >> U0028:08

U0028:08




Diagnostic Routine X

Diagnostic Overview

U0028:08 and U0028:88

Refer to Wiring Diagram Set 46 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The RCM (Restraints Control Module) supplies the stability/traction control system with the yaw rate, roll rate, lateral and longitudinal accelerometer over a dedicated CAN (Controller Area Network). If the RCM (Restraints Control Module) detects a fault with communications with the ABS (Anti-Lock Brake System) module or dedicated CAN (Controller Area Network) circuits, it sets DTC (Diagnostic Trouble Code) U0028:08 or U0028:88.

The RCM (Restraints Control Module) does not request the IPC (Instrument Panel Cluster) to illuminate the air bag warning indicator if either DTC (Diagnostic Trouble Code) U0028:08 or U0028:88 is set.

DTC Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- Inspect for damaged wiring harness(es)

- Inspect for a loose or damaged ABS (Anti-Lock Brake System) module connector

Pinpoint Test

WARNING: Do not handle, move or change the original horizontal mounting position of the RCM (Restraints Control Module) while the RCM (Restraints Control Module) is connected and the ignition switch is ON. Failure to follow this instruction may result in the accidental deployment of the Safety Canopy(R) and cause serious personal injury or death.

NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test.

NOTE:Only disconnect or reconnect SRS (Supplemental Restraint System) components 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: Always make sure the correct SRS (Supplemental Restraint System) component is being installed. Parts released for other vehicles may not be compatible even if they appear physically similar. Check the part number listed in the Ford Catalog Advantage or equivalent to make sure the correct component is being installed. If an incorrect SRS (Supplemental Restraint System) component is installed, DTCs (Diagnostic Trouble Codes) may set.

NOTE: The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.

1. RETRIEVE RCM (Restraints Control Module) DTCs (Diagnostic Trouble Codes)

1. Ignition ON.

2. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was DTC (Diagnostic Trouble Code) U0028:08 or U0028:88 retrieved on-demand during self-test?








2. VERIFY THE RCM (Restraints Control Module) PART NUMBER

1. Using the Log Viewer function of the scan tool, retrieve and record the RCM (Restraints Control Module) part number.

2. Check the part number recorded against the number listed in the Ford Catalog Advantage or equivalent and verify the correct RCM (Restraints Control Module) is present in the vehicle.

Is the correct RCM (Restraints Control Module) installed?








3. VERIFY THE ABS (Anti-Lock Brake System) MODULE PART NUMBER

1. Using the Log Viewer function of the scan tool, retrieve and record the ABS (Anti-Lock Brake System) module part number.

2. Check the part number recorded against the number listed in the Ford Catalog Advantage or equivalent and verify the correct ABS (Anti-Lock Brake System) module is present in the vehicle.

Is the correct ABS (Anti-Lock Brake System) module installed?








4. CHECK THE HS-CAN (High Speed Controller Area Network) COMMUNICATIONS (ABS (Anti-Lock Brake System) MODULE COMMUNICATIONS)

1. Using the scan tool, carry out the Network Test.

NOTE: The Network Test does not test the dedicated CAN (Controller Area Network) between the ABS (Anti-Lock Brake System) module and the RCM (Restraints Control Module).

Did the Network Test pass (ABS (Anti-Lock Brake System) module communicates with the scan tool)?








5. CHECK THE DEDICATED CAN (Controller Area Network) CIRCUITS FOR AN OPEN

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

3. Disconnect RCM (Restraints Control Module) C310A and C310B.

4. Disconnect ABS (Anti-Lock Brake System) Module C135.

5. Measure:





Are the resistances less than 3 ohms?








6. CHECK THE DEDICATED CAN (Controller Area Network) CIRCUITS FOR A SHORT TO VOLTAGE

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

3. Disconnect RCM (Restraints Control Module) C310A and C310B.

4. Disconnect ABS (Anti-Lock Brake System) Module C135.

5. 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 - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

6. Ignition ON.

7. Measure:





Is any voltage present?








7. CHECK THE DEDICATED CAN (Controller Area Network) CIRCUITS FOR A SHORT TO GROUND

1. Ignition OFF.

2. Measure:





Are the resistances greater than 10,000 ohms?








8. CHECK FOR A SHORT BETWEEN THE DEDICATED CAN (Controller Area Network) CIRCUITS

1. Measure:





Is the resistance greater than 10,000 ohms?








9. CHECK THE RCM (Restraints Control Module) TERMINATING RESISTOR

1. Connect RCM (Restraints Control Module) C310B.

2. Measure:





Is the resistance between 108 and 132 ohms?








10. CHECK THE ABS (Anti-Lock Brake System) MODULE TERMINATING RESISTOR

1. Disconnect RCM (Restraints Control Module) C310B.

2. Connect ABS (Anti-Lock Brake System) Module C135.

3. Measure:





Is the resistance between 108 and 132 ohms?








11. CONFIRM THE RCM (Restraints Control Module) FAULT

NOTE: Make sure all SRS (Supplemental Restraint System) components and the RCM (Restraints Control Module) electrical connectors are connected before carrying out the self-test. If not, DTCs (Diagnostic Trouble Codes) will be recorded.

1. 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 - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

2. Disconnect RCM (Restraints Control Module) C310A and C310B (if not previously disconnected).

3. Disconnect ABS (Anti-Lock Brake System) Module C135 (if not previously disconnected).

4. Prior to reconnecting any previously disconnected SRS (Supplemental Restraint System) component:

- inspect connector(s) (including any inline connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damaged, pinched, cut or pierced wires.
- inspect RCM (Restraints Control Module) C310A and C310B CPA (Connector Position Assurance) lever/lock for correct operation. REFER to Restraints Control Module (RCM) .
- inspect ABS (Anti-Lock Brake System) 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 for schematic and connector information Electrical Diagrams.


5. Connect ABS (Anti-Lock Brake System) Module C135 (if previously disconnected).

6. Connect RCM (Restraints Control Module) C310A and C310B (if previously disconnected).

7. 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 - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

8. Ignition ON.

9. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was DTC (Diagnostic Trouble Code) U0028:08 retrieved on-demand during self-test?








12. CONFIRM THE ABS (Anti-Lock Brake System) MODULE FAULT

NOTE: Make sure all SRS (Supplemental Restraint System) components and the RCM (Restraints Control Module) electrical connectors are connected before carrying out the self-test. If not, DTCs (Diagnostic Trouble Codes) will be recorded.

1. Disconnect RCM (Restraints Control Module) C310A and C310B.

2. Prior to reconnecting any previously disconnected SRS (Supplemental Restraint System) component:

- inspect connector(s) (including any inline connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damaged, pinched, cut or pierced wires.
- inspect RCM (Restraints Control Module) C310A and C310B CPA (Connector Position Assurance) lever/lock for correct operation. REFER to Restraints Control Module (RCM) .
- inspect ABS (Anti-Lock Brake System) 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 for schematic and connector information Electrical Diagrams.


3. Connect ABS (Anti-Lock Brake System) Module C135 (if previously disconnected).

4. Connect RCM (Restraints Control Module) C310A and C310B (if previously disconnected).

5. 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 - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

6. Ignition ON.

7. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was DTC (Diagnostic Trouble Code) U0028:08 retrieved on-demand during self-test?








13. CHECK FOR AN INTERMITTENT FAULT

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

3. Disconnect ABS (Anti-Lock Brake System) Module C135.

4. Disconnect RCM (Restraints Control Module) C310A and C310B.

- inspect connector(s) (including any inline connectors) for corrosion, pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damaged, pinched, cut or pierced wires.
- inspect RCM (Restraints Control Module) C310A and C310B CPA (Connector Position Assurance) lever/lock for correct operation. REFER to Restraints Control Module (RCM) .
- inspect ABS (Anti-Lock Brake System) 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 for schematic and connector information Electrical Diagrams.


5. Connect ABS (Anti-Lock Brake System) Module C135.

6. Connect RCM (Restraints Control Module) C310A and C310B.

7. 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 - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

8. Ignition ON.

9. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was DTC (Diagnostic Trouble Code) U0028:08 or U0028:88 retrieved on-demand during self-test?








14. CHECK FOR ADDITIONAL RCM (Restraints Control Module) AND ABS (Anti-Lock Brake System) MODULE DTCs (Diagnostic Trouble Codes)

1. 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.

2. Reconnect all SRS (Supplemental Restraint System) components (if previously disconnected).

3. 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 - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

4. Ignition ON.

5. Using a scan tool, perform RCM (Restraints Control Module) and ABS (Anti-Lock Brake System) module self-tests to retrieve DTCs (Diagnostic Trouble Codes).

Are any RCM (Restraints Control Module) and/or ABS (Anti-Lock Brake System) module DTCs (Diagnostic Trouble Codes) retrieved on-demand during self-test?







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