PINPOINT TEST T : DTCs U0028:08 AND U0028:88

WARNING: This page is about a different car, the 2016 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

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.
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 components when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.
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, DTCs may set.
NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

T1 RETRIEVE RCM DTCs

WARNING: Before beginning any service procedure, refer to Safety Warnings in Service Information

REFER to Safety Belt and SRS Health and Safety Precautions in Description and Operation in Service Information .

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 T2. For DTC U0028:88, GO to T5.
No	This is an intermittent fault when present as a CMDTC only. GO to T13.

T2 VERIFY THE RCM 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 T3.
No	INSTALL the correct RCM. REFER to Restraints Control Module (RCM) . GO to T14.

T3 VERIFY THE ABS 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 T4.
No	INSTALL the correct ABS module. REFER to Anti-Lock Brake System (ABS) and Stability Control . GO to T14.

T4 CHECK THE HS-CAN COMMUNICATIONS (ABS 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 diagnostic scan tool)?

Yes	GO to T5.
No	DIAGNOSE the HS-CAN /ABS module communication concern. REFER to Module Communications Network . GO to T14.

T5 CHECK THE DEDICATED CAN CIRCUITS FOR AN OPEN

Ignition OFF.

Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering .

Disconnect RCM C310A and C310B .

Disconnect ABS Module C135 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C135-37	Courtesy of FORD MOTOR COMPANY	C310B-60
C135-24	Courtesy of FORD MOTOR COMPANY	C310B-59

Are the resistances less than 5 ohms?

Yes	For DTC U0028:08, GO to T9. For DTC U0028:88, GO to T6.
No	REPAIR the affected circuit. Refer to Connector Repair Procedures for schematic and connector information. Go to T14.

T6 CHECK THE DEDICATED CAN CIRCUITS FOR A SHORT TO VOLTAGE

Repower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C135-24	Courtesy of FORD MOTOR COMPANY	Ground
C135-37	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the affected circuit. Refer to Connector Repair Procedures for schematic and connector information. Go to T14.
No	GO to T7.

T7 CHECK THE DEDICATED CAN CIRCUITS FOR A SHORT TO GROUND

Ignition OFF.

Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C135-24	Courtesy of FORD MOTOR COMPANY	Ground
C135-37	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes	GO to T8.
No	REPAIR the affected circuit. Refer to Connector Repair Procedures for schematic and connector information. Go to T14.

T8 CHECK FOR SHORT BETWEEN THE DEDICATED CAN CIRCUITS

Measure:

Positive Lead	Measurement / Action	Negative Lead
C135-24	Courtesy of FORD MOTOR COMPANY	C135-37

Is the resistance greater than 10, 000 ohms?

Yes	GO to T9.
No	REPAIR the circuits. Refer to Connector Repair Procedures for schematic and connector information. Go to T14.

T9 CHECK THE RCM TERMINATING RESISTOR

Connect RCM C310A and C310B .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C135-24	Courtesy of FORD MOTOR COMPANY	C135-37

Is the resistance between 108 and 132 ohms?

Yes	GO to T10.
No	GO to T11.

T10 CHECK THE ABS MODULE TERMINATING RESISTOR

Disconnect RCM C310B .

Connect ABS Module C135 .

Measure:

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

Is the resistance between 108 and 132 ohms?

Yes	For DTC U0028:08, GO to T11. For DTC U0028:88, GO to T12.
No	GO to T12.

T11 CONFIRM THE RCM FAULT

NOTE: Make sure all restraint system components, sensor electrical connectors and the RCM electrical connectors are connected before carrying out self-test. If not, 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 damage, pinched, cut or pierced wires.
- Inspect RCM C310A and C310B
  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 RCM C310A and C310B .

Connect ABS Module C135 .

Repower the SRS.
Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and 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 TSBs. If a TSB exists for this concern, discontinue this test and follow TSB instructions. If no TSBs address this concern, INSTALL a new RCM. REFER to Restraints Control Module (RCM) . GO to T14.
No	In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. Go to T13.

T12 CONFIRM THE ABS MODULE FAULT

NOTE: Make sure all restraint system components and the RCM electrical connectors are connected before carrying out self-test. If not, 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 damage, pinched, cut or pierced wires.
- Inspect RCM C310A and C310B
  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 RCM C310A and C310B .

Connect ABS Module C135 .

Repower the SRS.
Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and 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 TSBs. If a TSB exists for this concern, discontinue this test and follow TSB instructions. If no TSBs address this concern, INSTALL a new ABS module. REFER to the ABS Module Removal and Installation in Anti-Lock Brake System (ABS) and Stability Control . GO to T14.
No	In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. Go to T13.

T13 CHECK FOR AN INTERMITTENT FAULT

Ignition OFF.

Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering .

Disconnect RCM C310A and C310B .

Disconnect ABS module C135
:
- 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 damage, pinched, cut or pierced wires.
- Inspect RCM C310A and C310B
  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 RCM C310A and C310B .

Connect ABS Module C135 .

Repower the SRS.
Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and 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 T14.

The fault is not present and cannot be recreated at this time. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. GO to T14.

T14 CHECK FOR ADDITIONAL SRS OR ABS DTCs

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.

Ignition OFF.

Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering .

Connect RCM C310A and C310B (if previously disconnected).

Connect ABS Module C135 (if previously disconnected).

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

Ignition ON.

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

Using a diagnostic scan tool, perform the ABS module self-test.

Are any RCM and/or ABS module DTCs retrieved on-demand during self-test?

Yes	Do not clear any DTCs until all DTCs have been resolved. For RCM DTCs, DIAGNOSE and REPAIR the RCM DTCs. REFER to Restraints Control Module (RCM) DTC Chart for pinpoint test direction. For ABS module DTCs, DIAGNOSE and REPAIR the ABS module DTCs. REFER to Anti-Lock Brake System (ABS) and Stability Control for pinpoint test direction.
No	The repair is complete. RETURN the vehicle to the customer.