501-20B Supplemental Restraint System 2014 Fiesta
Diagnosis and Testing Procedure revision date: 05/6/2013

Pinpoint Test - DTC: C

B0004:11, B0004:12, B0004:13 and B0004:1A


Refer to Wiring Diagrams Cell 46 for schematic and connector information.

Normal Operation and Fault Conditions

The RCM continuously monitors the driver lower airbag circuits for the following faults:

If a fault is detected, the RCM stores DTC B0004:11, B0004:12, B0004:13 or B0004:1A in memory and sends a message to the IPC to illuminate the airbag warning indicator.

The RCM analyzes the deployment loop resistance to determine if a fault exists. The value displayed in the PID is the deployment loop resistance measured by the RCM . If the value displayed is lower or higher than the desired range (refer to diagram below), the RCM can set a DTC . As the deployment loop resistance drifts farther outside the desired range, the chance for a DTC increases. Small variations in resistance can occur due to the effect of road vibrations on terminal fit. Crimps and terminals can be affected by stress and harness movement and can cause an increase in resistance due to wire strain. These variables can result in an intermittent fault. For this reason, the test requires the PID value to be within the desired range before the fault is considered repaired, regardless if the module is reporting an on-demand DTC at the time of diagnosis. Following this direction helps make sure that minor changes in resistance do not create a repeat concern. This test uses process of elimination to diagnose each part of the deployment loop circuit including:



  DTC Fault Trigger Conditions


  DTC Description Fault Trigger Conditions
B0004:11 Driver Knee Bolster Deployment Control: Circuit Short to Ground A fault is indicated when the RCM senses a short to ground on either driver lower airbag circuit for approximately 6 seconds.
B0004:12 Driver Knee Bolster Deployment Control: Circuit Short to Battery A fault is indicated when the RCM senses a short to voltage on either driver lower airbag circuit for approximately 6 seconds.
B0004:13 Driver Knee Bolster Deployment Control: Circuit Open A fault is indicated when the RCM measures more than the desired resistance range between driver lower airbag circuits for approximately 6 seconds.
B0004:1A Driver Knee Bolster Deployment Control: Circuit Resistance Below Threshold A fault is indicated when the RCM measures less than the desired resistance range between driver lower airbag circuits for approximately 6 seconds.


Possible Causes

Visual Inspection and Diagnostic Pre-checks


PINPOINT TEST A : B0004:11, B0004:12, B0004:13 AND B0004:1A
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, 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 B0004:11, B0004:12, B0004:13 or B0004:1A 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 B0004:13 or B0004:1A, GO to A2
For DTC B0004:11, GO to A8
For DTC B0004:12, GO to A10
No This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only.
For DTC B0004:13 or B0004:1A, GO to A13
For DTC B0004:11, GO to A14
For DTC B0004:12, GO to A15


A2   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL RESISTANCE (DEPLOY_02_R) PID (PARAMETER IDENTIFICATION)
  • Using a diagnostic scan tool, view RCM Parameter Identifications (PIDs).
  • Monitor and record the resistance value displayed by the DEPLOY_02_R PID .

Does the PID value read between 1.44 and 3.52 ohms?

Yes GO to A12
No GO to A3


A3   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL RESISTANCE (DEPLOY_02_R) PID (PARAMETER IDENTIFICATION) WHILE CARRYING OUT THE HARNESS TEST
  • While monitoring the DEPLOY_02_R PID , carry out the harness test of the driver lower airbag circuits and accessible connectors (including any inline connectors) by wiggling and flexing the wire harness and connectors frequently. Record the resistance value indicated by the PID .

Does the PID value read between 1.44 and 3.52 ohms while carrying out the harness test?

Yes DEPOWER the SRS and REPAIR the connector, terminals or wire harness as needed.
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17
No For PID value less than 1.44 ohms, GO to A4
For PID value greater than 3.52 ohms, GO to A6


A4   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL DTC (DIAGNOSTIC TROUBLE CODE) FOR A FAULT STATUS CHANGE (LOW RESISTANCE INDICATED)

NOTE: This pinpoint test step attempts to change the fault reported by the RCM by inducing a different fault condition. If the reported fault changes, this indicates the RCM is functioning correctly and is not the source of the fault.

  • Ignition OFF.
  • Remove the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Ignition ON.
  • Using a diagnostic scan tool, perform RCM self-test.
  • DIAGNOSTIC TIP: When viewing Diagnostic Trouble Codes (DTCs) with the driver lower airbag disconnected, an open circuit fault is normally retrieved.

Did the on-demand DTC change from B0004:1A to B0004:13?

Yes GO to A11
No GO to A5


A5   CHECK FOR A SHORT BETWEEN DRIVER LOWER AIRBAG CIRCUITS
  • Ignition OFF.
  • Disconnect: RCM C310A and C310B.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C2432-1   C2432-2



Is the resistance greater than 10,000 ohms?

Yes GO to A12
No REPAIR the circuits.
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17


A6   CHECK THE DRIVER LOWER AIRBAG CIRCUITS FOR AN OPEN
  • Ignition OFF.
  • Remove the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Disconnect: RCM C310A and C310B.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C310A-11   C2432-1
      C310A-12   C2432-2



Are the resistances less than 0.5 ohm?

Yes GO to A7
No REPAIR the circuit(s).
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17


A7   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL DTC (DIAGNOSTIC TROUBLE CODE) FOR A FAULT STATUS CHANGE (OPEN INDICATED)

NOTE: This pinpoint test step attempts to change the fault reported by the RCM by inducing a different fault condition. If the reported fault changes, this indicates the RCM is functioning correctly and is not the source of the fault.

  • Connect: RCM C310A and C310B.
  • Connect a fused jumper wire:


    Lead 1 Measurement / Action Lead 2
      C2432-1   C2432-2


  • Ignition ON.
  • Using a diagnostic scan tool, perform RCM self-test.
  • DIAGNOSTIC TIP: When viewing Diagnostic Trouble Codes (DTCs) with the driver lower airbag circuits shorted together, a low resistance fault is normally retrieved.

Did the on-demand DTC change from B0004:13 to B0004:1A?

Yes REMOVE the fused jumper wire and GO to A11
No REMOVE the fused jumper wire and GO to A12


A8   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL DTC (DIAGNOSTIC TROUBLE CODE) FOR A FAULT STATUS CHANGE (SHORT TO GROUND INDICATED)

NOTE: This pinpoint test step attempts to change the fault reported by the RCM by inducing a different fault condition. If the reported fault changes, this indicates the RCM is functioning correctly and is not the source of the fault.

  • Ignition OFF.
  • Remove the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Ignition ON.
  • Using a diagnostic scan tool, perform RCM self-test.
  • DIAGNOSTIC TIP: When viewing Diagnostic Trouble Codes (DTCs) with the driver lower airbag disconnected, an open circuit fault is normally retrieved.

Did the on-demand DTC change from B0004:11 to B0004:13?

Yes GO to A11
No GO to A9


A9   CHECK THE DRIVER LOWER AIRBAG CIRCUITS FOR A SHORT TO GROUND
  • Ignition OFF.
  • Disconnect: RCM C310A and C310B.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C2432-1   Ground
      C2432-2   Ground



Are the resistances greater than 10,000 ohms?

Yes GO to A12
No REPAIR the circuit(s).
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17


A10   CHECK THE DRIVER LOWER AIRBAG CIRCUITS FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Remove the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Disconnect: RCM C310A and C310B.
  • Ignition ON.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C2432-1   Ground
      C2432-2   Ground



Is any voltage present?

Yes REPAIR the circuit(s).
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17
No GO to A12


A11   CONFIRM THE DRIVER LOWER AIRBAG 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.

  • Ignition OFF.
  • 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.
    • repair any concerns found.
      Refer to Wiring Diagrams Cell 5 for schematic and connector information.
  • Install the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Connect: RCM C310A and C310B.
  • Ignition ON.
  • Using a diagnostic scan tool, perform RCM self-test.

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

Yes INSTALL a new driver lower airbag.
REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
GO to A17
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.
For DTC B0004:13 or B0004:1A, GO to A13
For DTC B0004:11, GO to A14
For DTC B0004:12, GO to A15


A12   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.

  • Ignition OFF.
  • 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.
    • repair any concerns found.
      Refer to Wiring Diagrams Cell 5 for schematic and connector information.
  • Install the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Connect: RCM C310A and C310B.
  • 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) (501-20B Supplemental Restraint System, Removal and Installation).
GO to A17
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.
For DTC B0004:13 or B0004:1A, GO to A13
For DTC B0004:11, GO to A14
For DTC B0004:12, GO to A15


A13   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL RESISTANCE (DEPLOY_02_R) PID (PARAMETER IDENTIFICATION) FOR AN INTERMITTENT LOW RESISTANCE OR OPEN CIRCUIT FAULT
  • Using a diagnostic scan tool, view RCM Parameter Identifications (PIDs).
  • While monitoring the DEPLOY_02_R PID , attempt to recreate the fault by wiggling connectors (including any inline connectors) and flexing the wire harness frequently. Record the resistance value indicated by the PID .

Does the PID value read between 1.44 and 3.52 ohms?

Yes 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 A16
No DEPOWER the SRS and REPAIR as necessary.
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17


A14   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL CIRCUITS FOR AN INTERMITTENT SHORT TO GROUND FAULT
  • Attempt to recreate the fault by wiggling connectors (including any inline connectors) and flexing the wire harness frequently.
  • Using a diagnostic scan tool, perform RCM self-test.

Was DTC B0004:11 retrieved on-demand during self-test?

Yes DEPOWER the SRS and REPAIR as necessary.
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17
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 A16


A15   CHECK THE DRIVER KNEE BOLSTER DEPLOYMENT CONTROL CIRCUITS FOR AN INTERMITTENT SHORT TO BATTERY FAULT
  • Ignition OFF.
  • Remove the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Ignition ON.
  • Attempt to recreate the fault by wiggling connectors (including any inline connectors) and flexing the wire harness frequently.
  • Using a diagnostic scan tool, perform RCM self-test.

Was DTC B0004:12 retrieved on-demand during self-test?

Yes DEPOWER the SRS and REPAIR as necessary.
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17
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 A16


A16   CHECK THE HARNESS AND CONNECTORS
  • Ignition OFF.
  • Remove the driver lower airbag.
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
    • Inspect connector(s) (including any inline 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.
    • Inspect RCM C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation.

Were any concerns found?

Yes REPAIR as necessary.
Refer to Wiring Diagrams Cell 5 for schematic and connector information.
GO to A17
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 A17


A17   CHECK FOR ADDITIONAL SRS (SUPPLEMENTAL RESTRAINT SYSTEM) DIAGNOSTIC TROUBLE CODES (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.
  • Remove the driver lower airbag (if previously removed).
    REFER to: Driver Knee Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Reconnect all SRS components (if previously disconnected).
  • Ignition ON.
  • NOTE: When selecting Restraints from the Self Test menu, DTCs are retrieved from the RCM and OCSM .

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

Are any RCM and/or OCSM 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. DIAGNOSE and REPAIR the RCM and/or OCSM Diagnostic Trouble Codes (DTCs).
REFER to: Airbag Supplemental Restraint System (SRS) (501-20B Supplemental Restraint System, Diagnosis and Testing).
No CLEAR Continuous Memory Diagnostic Trouble Codes (CMDTCs) in all modules. PROVE OUT the SRS . The repair is complete. RETURN the vehicle to the customer.





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