Pinpoint Test Z - DTC: U0028:08 and U0028:88

Refer to Supplemental Restraint System for schematic and connector information.

Normal Operation and Fault Conditions 

The RCM supplies the stability/traction control system with the yaw rate, roll rate, lateral and longitudinal accelerometer over a dedicated CAN. If the RCM detects a communications fault with the ABS module or dedicated CAN circuits, it sets DTC U0028:08 or U0028:88.

The RCM does not  request the IPC module to illuminate the airbag warning indicator if either DTC U0028:08 or U0028:88 is set.

DTC Fault Trigger Conditions 

Possible Causes 

• Wiring, terminals or connectors
• ABS module
• RCM

Visual Inspection and Diagnostic Pre-checks 

• Inspect for damaged wiring harness(es).
• Inspect for a loose or damaged ABS module connector.

PINPOINT TEST A : U0028:08 AND U0028:88 

1. WARNING: Incorrect repair techniques or actions can cause an accidental Supplemental Restraint System (SRS) deployment. Never compromise or depart from these instructions. Failure to precisely follow all instructions could result in serious personal injury from an accidental deployment.
2. NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test.
3. NOTE: Only disconnect or reconnect SRS components when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.
4. NOTE: Always make sure the correct SRS 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 parts catalog to make sure the correct component is being installed. If an incorrect SRS component is installed, Diagnostic Trouble Codes (DTCs) may set.
5. NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
6. A1 RETRIEVE RCM (RESTRAINTS CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
   
   
   • WARNING: Before beginning any service procedure, refer to Safety Warnings in General Information. Failure to follow this instruction may result in serious personal injury.

     REFER to: Pyrotechnic Device Health and Safety Precautions .

   • Ignition ON.
   • Using a diagnostic scan tool, perform RCM self-test.

   Was DTC U0028:08 or U0028:88 retrieved on-demand during self-test? 

   Yes	This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test. For DTC U0028:08, GO to  A2. For DTC U0028:88, GO to  A5

   No	This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only. GO to  A13

7. A2 VERIFY THE RCM (RESTRAINTS CONTROL MODULE) PART NUMBER
   
   
   • Using the Log Viewer function of the diagnostic scan tool, retrieve and record the RCM part number.
   • Check the part number recorded against the number listed in the parts catalog and verify the correct RCM is present in the vehicle.

   Is the correct RCM installed? 

   Yes

   GO to  A3

   No	INSTALL the correct RCM. Refer to: Restraints Control Module (RCM) . Go to  A14

8. A3 VERIFY THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE PART NUMBER
   
   
   • Using the Log Viewer function of the diagnostic scan tool, retrieve and record the ABS module part number.
   • Check the part number recorded against the number listed in the parts catalog and verify the correct ABS module is present in the vehicle.

   Is the correct ABS module installed? 

   Yes

   GO to  A4

   No	INSTALL the correct ABS module. Refer to: Hydraulic Control Unit (HCU) . Go to  A14

9. A4 CHECK THE HS-CAN (HIGH SPEED-CONTROLLER AREA NETWORK) COMMUNICATIONS (ABS (ANTI-LOCK BRAKE SYSTEM) MODULE COMMUNICATIONS)
   
   
   • NOTE: The Network Test does not test the dedicated CAN communications between the ABS module and RCM.

     Using a diagnostic scan tool, perform a Network Test.

   Did the Network Test pass (ABS module communicates with the scan tool)? 

   Yes

   GO to  A5

   No	DIAGNOSE the HS-CAN/ ABS module communication concern. Refer to: Communications Network . Go to  A14

10. A5 CHECK THE DEDICATED CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR AN OPEN
    
    
    • Ignition OFF.
    • Depower the SRS. Refer to: Supplemental Restraint System (SRS) Depowering .
    • Disconnect: RCM C310A and C310B .
    • Disconnect: ABS module C135 .
    • Measure:

      Positive Lead	Measurement / Action	Negative Lead
      C310B-60	Courtesy of FORD MOTOR COMPANY	C135-32
      C310B-59	Courtesy of FORD MOTOR COMPANY	C135-33

    Are the resistances less than 5 ohms? 

    Yes	For DTC U0028:08, GO to  A9. For DTC U0028:88, GO to  A6

    No	REPAIR the affected circuit. Refer to Connector Repair Procedures for schematic and connector information. Go to  A14

11. A6 CHECK THE DEDICATED CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR A SHORT TO VOLTAGE
    
    
    • Repower the SRS.

      Do not  prove out the SRS at this time. Refer to: Supplemental Restraint System (SRS) Repowering .

    • Ignition ON.
    • Measure:

      Positive Lead	Measurement / Action	Negative Lead
      C135-32	Courtesy of FORD MOTOR COMPANY	Ground
      C135-33	Courtesy of FORD MOTOR COMPANY	Ground

    Is voltage present on either circuit? 

    Yes	REPAIR the affected circuit(s). Refer to Connector Repair Procedures for schematic and connector information. Go to  A14

    No

    GO to  A7

12. A7 CHECK THE DEDICATED CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR A SHORT TO GROUND
    
    
    • Ignition OFF.
    • Depower the SRS. Refer to: Supplemental Restraint System (SRS) Depowering .
    • Measure:

      Positive Lead	Measurement / Action	Negative Lead
      C135-32	Courtesy of FORD MOTOR COMPANY	Ground
      C135-33	Courtesy of FORD MOTOR COMPANY	Ground

    Are the resistances greater than 10, 000 ohms? 

    Yes

    GO to  A8

    No	REPAIR the affected circuit(s). Refer to Connector Repair Procedures for schematic and connector information. Go to  A14

13. A8 CHECK FOR A SHORT BETWEEN THE DEDICATED CAN (CONTROLLER AREA NETWORK) CIRCUITS
    
    
    • Measure:

      Positive Lead	Measurement / Action	Negative Lead
      C135-32	Courtesy of FORD MOTOR COMPANY	C135-33

    Is the resistance greater than 10, 000 ohms? 

    Yes

    GO to  A9

    No	REPAIR the circuit(s). Refer to Connector Repair Procedures for schematic and connector information. Go to  A14

14. A9 CHECK THE RCM (RESTRAINTS CONTROL MODULE) TERMINATING RESISTOR
    
    
    • Connect: RCM C310B .
    • Measure:

      Positive Lead	Measurement / Action	Negative Lead
      C135-32	Courtesy of FORD MOTOR COMPANY	C135-33

    Is the resistance between 108 and 132 ohms? 

    Yes	GO to  A10

    No	GO to  A11

15. A10 CHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE TERMINATING RESISTOR
    
    
    • Disconnect: RCM C310B .
    • Connect: ABS module C135 .
    • Measure:

      Positive Lead	Measurement / Action	Negative Lead
      C310B-59	Courtesy of FORD MOTOR COMPANY	C310B-60

    Is the resistance between 108 and 132 ohms? 

    Yes	For DTC U0028:08, GO to  A11. For DTC U0028:88, GO to  A12

    No	GO to  A12

16. A11 CONFIRM THE RCM (RESTRAINTS CONTROL MODULE) FAULT
    
    
    NOTE: Make sure all SRS components and the RCM electrical connectors are connected before carrying out the self-test. If not, Diagnostic Trouble Codes (DTCs) will be recorded.
    • Disconnect: RCM C310A and C310B (if not previously disconnected).
    • Disconnect: ABS module C135 (if not previously disconnected).
    • Prior to reconnecting any previously disconnected SRS 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 C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation.
      • 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 Connector Repair Procedures for schematic and connector information.

    • Connect: ABS module C135 .
    • Connect: RCM C310A and C310B .
    • Repower the SRS.

      Do not  prove out the SRS at this time. Refer to: Supplemental Restraint System (SRS) Repowering .

    • Ignition ON.
    • Using a diagnostic scan tool, perform RCM self-test.

    Was the original DTC retrieved on-demand during self-test? 

    Yes	CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new RCM. Refer to: Restraints Control Module (RCM) . Go to  A14

    No	In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time. Install SRS components only when directed to do so in the pinpoint test. GO to  A13

17. A12 CONFIRM THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE FAULT
    
    
    NOTE: Make sure all SRS components and the RCM electrical connectors are connected before carrying out the self-test. If not, Diagnostic Trouble Codes (DTCs) will be recorded.
    • Disconnect: RCM C310A and C310B (if not previously disconnected).
    • Disconnect: ABS module C135 (if not previously disconnected).
    • Prior to reconnecting any previously disconnected SRS 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 C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation.
      • 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 Connector Repair Procedures for schematic and connector information.

    • Connect: ABS module C135 .
    • Connect: RCM C310A and C310B .
    • Repower the SRS.

      Do not  prove out the SRS at this time. Refer to: Supplemental Restraint System (SRS) Repowering .

    • Ignition ON.
    • Using a diagnostic scan tool, perform RCM self-test.

    Was the original DTC retrieved on-demand during self-test? 

    Yes	CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new ABS module. Refer to: Hydraulic Control Unit (HCU) . Go to  A14

    No	In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time. Install SRS components only when directed to do so in the pinpoint test. GO to  A13

18. A13 CHECK FOR AN INTERMITTENT FAULT
    
    
    • Ignition OFF.
    • Depower the SRS. Refer to: Supplemental Restraint System (SRS) Depowering .
    • Disconnect: ABS module C135 .
    • Disconnect: RCM C310A and C310B .
      • 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 C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation.
      • 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 Connector Repair Procedures for schematic and connector information.

    • Connect: ABS module C135 .
    • Connect: RCM C310A and C310B .
    • Repower the SRS.

      Do not  prove out the SRS at this time. Refer to: Supplemental Restraint System (SRS) Repowering .

    • Ignition ON.
    • Using a diagnostic scan tool, perform RCM self-test.

    Was DTC U0028:08 or U0028:88 retrieved on-demand during self-test? 

    Yes

    This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test. CHECK for causes of the intermittent fault in the areas previously worked in, particularly the pins and terminals of any electrical connector that were disconnected. REPAIR any intermittent wiring, terminal or connector concerns found. Refer to Connector Repair Procedures for schematic and connector information. Go to  A14

    No	The fault is not present and cannot be recreated at this time. Do not install any new SRS components at this time. Install SRS components only when directed to do so in the pinpoint test. GO to  A14

19. A14 CHECK FOR ADDITIONAL SRS (SUPPLEMENTAL RESTRAINT SYSTEM) DIAGNOSTIC TROUBLE CODES (DTCS)
    
    
    • Ignition OFF.
    • Connect: ABS module C135 (if previously disconnected).
    • Connect: RCM C310A and C310B (if previously disconnected).
    • If previously directed to depower the SRS, repower the SRS.

      Do not  prove out the SRS at this time. Refer to: Supplemental Restraint System (SRS) Repowering .

    • Ignition ON.
    • Using a diagnostic scan tool, perform RCM self-test.
    • Using a diagnostic scan tool, perform ABS module self-test.

    Are any RCM and/or ABS module Diagnostic Trouble Codes (DTCs) retrieved on-demand during self-test? 

    Yes

    Do not clear any Diagnostic Trouble Codes (DTCs) until all Diagnostic Trouble Codes (DTCs) have been resolved. For RCM Diagnostic Trouble Codes (DTCs), REFER to: Airbag Supplemental Restraint System (SRS) . For ABS module Diagnostic Trouble Codes (DTCs), REFER to: Anti-Lock Brake System (ABS) and Stability Control .

    No	The repair is complete. RETURN the vehicle to the customer.