Pinpoint Test A : U0028:88

WARNING: Do not handle, move or change the original horizontal mounting position of the Restraints Control Module (RCM) while the Restraints Control Module (RCM) is connected and the ignition switch is ON. Failure to follow this instruction may result in the accidental deployment of the Safety Canopy® 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 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 Catalog Advantage™ or equivalent to make sure the correct component is being installed. If an incorrect SRS component is installed, Diagnostic Trouble Codes (DTCs) may set.

NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

A1 RETRIEVE RCM (RESTRAINTS CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, perform RCM self-test.
Was DTC U0028:88 retrieved on-dem and during self-test?
1. Yes: This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-dem and during self-test. GO to A2
2. No: This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only. GO to A9

A2 CHECK THE DEDICATED CAN (CONTROLLER AREA NETWORK) 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:

Click to display connectors

Positive Lead	Measurement / Action	Negative Lead
C135-5	Ω	C310B-32
C135-6	Ω	C310B-31

Are the resistances less than 3 ohms?

Yes: GO to A3
No: REPAIR the affected circuit.
Refer to OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.

GO to A10

A3 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) Depowering and Repowering .
Ignition ON.
Measure:

Click to display connectors

Positive Lead	Measurement / Action	Negative Lead
C135-5		-
C135-6		-

Is any voltage present?

Yes: REPAIR the affected circuit. GO to A10
No: GO to A4

A4 CHECK THE DEDICATED CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR A SHORT TO GROUND

Ignition OFF.
Measure:

Click to display connectors

Positive Lead	Measurement / Action	Negative Lead
C135-5	Ω	-
C135-6	Ω	-

Are the resistances greater than 10, 000 ohms?

Yes: GO to A5
No: REPAIR the affected circuit.
Refer to OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.

GO to A10

A5 CHECK FOR A SHORT BETWEEN THE DEDICATED CAN (CONTROLLER AREA NETWORK) CIRCUITS

Measure:

Click to display connectors

Positive Lead	Measurement / Action	Negative Lead
C135-5	Ω	C135-6

Is the resistance greater than 10, 000 ohms?

Yes: GO to A6
No: REPAIR the affected circuits.
Refer to OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.

GO to A10

A6 CHECK THE RCM (RESTRAINTS CONTROL MODULE) TERMINATING RESISTOR

Depower the SRS.
REFER to: Supplemental Restraint System (SRS) Depowering and Repowering .
Connect RCM C310B.
Measure:

Click to display connectors

Positive Lead	Measurement / Action	Negative Lead
C135-5	Ω	C135-6

Is the resistance between 108 and 132 ohms?

Yes: GO to A7
No: GO to A8

A7 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).
- 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.
    REFER to: Restraints Control Module (RCM) .
  - 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 OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.
- Connect ABS Module C135 (if previously disconnected).
- Connect RCM C310A and C310B (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.
Was DTC U0028:88 retrieved on-dem and during self-test?
1. 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 A10
2. 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 A9
A8 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.
- 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.
    REFER to: Restraints Control Module (RCM) .
  - 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 OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.
- 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.
Was DTC U0028:88 retrieved on-dem and during self-test?
1. 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 A10
2. 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 A9
A9 CHECK FOR AN INTERMITTENT FAULT
- Ignition OFF.
- Depower the SRS.
  REFER to: Supplemental Restraint System (SRS) Depowering and Repowering .
- Disconnect ABS Module C135.
- Disconnect RCM 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 C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation.
    REFER to: Restraints Control Module (RCM) .
  - 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 OEM 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) Depowering and Repowering .
- Ignition ON.
- Using a diagnostic scan tool, perform RCM self-test.
Was DTC U0028:88 retrieved on-dem and during self-test?
1. Yes: This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-dem and 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 OEM CONNECTOR REPAIR PROCEDURES for schematic and connector information.
  
  GO to A10
2. 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 A10
A10 CHECK FOR ADDITIONAL RCM (RESTRAINTS CONTROL MODULE) AND ABS (ANTI-LOCK BRAKE SYSTEM) MODULE DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition OFF.
- Depower the SRS.
  REFER to: Supplemental Restraint System (SRS) Depowering and Repowering .
- Reconnect all SRS components (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) Depowering and 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-dem and during self-test?
1. Yes: Do not clear any Diagnostic Trouble Codes (DTCs) until all Diagnostic Trouble Codes (DTCs) have been resolved. Refer to RCM DTC CHART or
  REFER to: ANTI-LOCK BRAKE SYSTEM (ABS) AND STABILITY CONTROL .
  
  for pinpoint test direction.
2. No: CLEAR all Continuous Memory Diagnostic Trouble Codes (CMDTCs) in all modules. PROVE OUT the SRS. The repair is complete. RETURN the vehicle to the customer.