FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Ford >> 2010 >> Taurus AWD V6-3.5L Turbo >> Repair and Diagnosis >> Restraints and Safety Systems >> Air Bag Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Tests AK: DTCs U0028:08 And U0028:88

Pinpoint Tests AK: DTCs U0028:08 And U0028:88




Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)

Pinpoint Test - Restraints Control Module (RCM)

Pinpoint Test AK: DTCs U0028:08 and U0028:88

Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number

Normal Operation

The Restraints Control Module (RCM) supplies the stability/traction control system with the yaw rate, roll rate, lateral and longitudinal accelerometer over a dedicated Controller Area Network 2 (CAN2) bus. If the RCM detects a fault with communications with the ABS module or CAN2 bus circuits, it will set DTC U0028:08 or U0028:88.

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

- DTC U0028:08 (Vehicle Communication Bus A: Bus Signal / Message Failures) - When the RCM does not receive CAN2 bus messages from the ABS module for 5 seconds, a fault will be indicated. An open CAN2 circuit, incorrectly installed ABS module or loss of power and/or ground to the ABS module can set this DTC.
- DTC U0028:88 (Vehicle Communication Bus A: Bus Off) - When the RCM detects the CAN2 circuits are shorted to ground, shorted to voltage or shorted to each other, a fault will be indicated.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RCM
- ABS module



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

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 safety belt buckle/retractor pretensioners or adaptive load limiting retractors or probe the electrical connectors. Failure to follow this instruction may result in the accidental deployment of the safety belt pretensioners or adaptive load limiting retractors which increases the risk of serious personal injury or death.

NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.

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

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.

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(TM) or equivalent 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.

-------------------------------------------------
AK1 RETRIEVE RCM DTCs


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- 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 AK2.

For DTC U0028:88, GO to AK6.

No
This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only. GO to AK13.

-------------------------------------------------
AK2 CHECK FOR CORRECT RCM


- 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.
- Access to the RCM. Refer to Restraints Control Module (RCM) Service and Repair. Check the part number on the RCM against the number listed in the Ford Catalog Advantage(TM) or equivalent.
- Does the part number match?

Yes
GO to AK3.

No
INSTALL the correct RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to AK14.

-------------------------------------------------
AK3 CHECK FOR CORRECT ABS MODULE


- Gain access the ABS module. Check the part number on the ABS module against the part number listed in the Ford Catalog Advantage(TM) or equivalent.
- Does the part number match?

Yes
GO to AK4.

No
INSTALL the correct ABS module. REFER to Antilock Brakes / Traction Control Systems. GO to AK14.

-------------------------------------------------
AK4 CHECK THE HS-CAN COMMUNICATIONS (ABS MODULE COMMUNICATIONS)


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Network Test.
- NOTE: The Network Test does not test the CAN2 communications between the ABS module and RCM.
The CAN2 is a dedicated communication network between the 2 modules.
- Did the Network Test pass (ABS module communicates with the scan tool)?

Yes
GO to AK5.

No
REFER to Information Bus to diagnose the High Speed Controller Area Network (HS-CAN)/ABS module communication concern.
GO to AK14.

-------------------------------------------------
AK5 CHECK THE CAN2 CIRCUITS FOR AN OPEN


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM C310A and C310B.
- Disconnect: ABS Module C135.
- Measure the resistance between the ABS module C135, harness side and the RCM C310B, harness side as indicated in the following chart:









- Are the resistances less than 5 ohms?

Yes
GO to AK9.

No
REPAIR circuits VCA24 (GN/OG) and VCA23 (BU/WH). GO to AK14.

-------------------------------------------------
AK6 CHECK THE CAN2 CIRCUITS FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM C310A and C310B.
- Disconnect: ABS Module C135.
- Repower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Measure the voltage between ABS module:
- C135-37, circuit VCA23 (BU/WH), harness side and ground.
- C135-24, circuit VCA24 (GN/OG), harness side and ground.




- Is voltage present on either circuit?

Yes
REPAIR circuit VCA24 (GN/OG) or VCA23 (BU/WH). GO to AK14.

No
GO to AK7.

-------------------------------------------------
AK7 CHECK THE CAN2 CIRCUITS FOR A SHORT TO GROUND


- Ignition OFF.
- Measure the resistance between ABS module:
- C135-37, circuit VCA23 (BU/WH), harness side and ground.
- C135-24, circuit VCA24 (GN/OG), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to AK8.

No
REPAIR circuit VCA24 (GN/OG) or VCA23 (BU/WH). GO to AK14.

-------------------------------------------------
AK8 CHECK FOR SHORT BETWEEN CAN2 CIRCUITS


- Measure the resistance between ABS module C135-37, circuit VCA23 (BU/WH), harness side and C135-24, circuit VCA24 (GN/OG), harness side.




- Is the resistance greater than 10,000 ohms?

Yes
GO to AK9.

No
REPAIR circuits VCA24 (GN/OG) and VCA23 (BU/WH). GO to AK14.

-------------------------------------------------
AK9 CHECK THE RCM TERMINATING RESISTOR


- Repower the SRS. Do not prove out the SRS at this time.
Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Connect: RCM C310B.
- Measure the resistance between ABS module C135-37, circuit VCA23 (BU/WH), harness side and C135-24, circuit VCA24 (GN/OG), harness side.




- Is the resistance between 108 and 132 ohms?

Yes
GO to AK10.

No
GO to AK11.

-------------------------------------------------
AK10 CHECK THE ABS MODULE TERMINATING RESISTOR


- Disconnect: RCM C310B.
- Connect: ABS Module C135.
- Measure the resistance between RCM C310B-20, circuit VCA23 (BU/WH), harness side and C310B-19, circuit VCA24 (GN/OG), harness side.




- Is the resistance between 108 and 132 ohms?

Yes
For DTC U0028:08, GO to AK11.

For DTC U0028:88, GO to AK12.

No
GO to AK12.

-------------------------------------------------
AK11 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.

- Prior to reconnecting any previously disconnected SRS 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 C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation. Refer to Restraints Control Module (RCM) Service and Repair.
- 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. Diagrams By Number

- Connect: All Previously Disconnected Component(s)/Connector(s).
- Repower the SRS. Do not prove out the SRS at this time.
Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC U0028:08 retrieved on-demand during self-test?

Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to AK14.

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 AK13.

-------------------------------------------------
AK12 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.

- Prior to reconnecting any previously disconnected SRS 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 C310A and C310B CPA lever/lock for correct operation. Refer to Restraints Control Module (RCM) Service and Repair.
- 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. Diagrams By Number

- Connect: All Previously Disconnected Component(s)/Connector(s).
- Repower the SRS. Do not prove out the SRS at this time.
Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC U0028:88 retrieved on-demand during self-test?

Yes
INSTALL a new ABS module. REFER to the ABS Module Removal and Installation in Antilock Brakes / Traction Control Systems. GO to AK14.

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 AK13.

-------------------------------------------------
AK13 CHECK FOR AN INTERMITTENT FAULT


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect RCM 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. Diagrams By Number

- Connect: All Previously Disconnected Component(s)/Connector(s).
- Repower the SRS. Do not prove out the SRS at this time.
Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- 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 Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

GO to AK14.

No
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 AK14.

-------------------------------------------------
AK14 CHECK FOR ADDITIONAL RCM 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 components (if previously disconnected).
- If previously directed to depower the SRS, repower the SRS. Do notprove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Enter the following diagnostic mode on the scan tool: Self Test - ABS Module.
- Are any DTCs retrieved from the RCM 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 Antilock Brakes / Traction Control Systems for pinpoint test direction. [1][2]Diagnostic Trouble Code Descriptions

No
CLEAR all CMDTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.

-------------------------------------------------
pro multis Credits:Operation CHARM About Operation CHARM