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Home >> Ford >> 2012 >> Focus L4-2.0L >> Repair and Diagnosis >> Restraints and Safety Systems >> Air Bag Systems >> Testing and Inspection >> Pinpoint Tests >> Diagnostic Routine F >> Part 1

Part 1




Diagnostic Routine F

Diagnostic Overview

B0021:11, B0021:12, B0021:13 and B0021:1A

Refer to Wiring Diagram Set 46 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The RCM (Restraints Control Module) continuously monitors the LH (Left Hand) side air curtain module circuits for the following faults:

- Resistance out of range

- Unexpected voltage

- Short to ground

- Faulted LH (Left Hand) side air curtain module

If a fault is detected, the RCM (Restraints Control Module) stores DTC (Diagnostic Trouble Code) B0021:11, B0021:12, B0021:13 or B0021:1A in memory and sends a message to the IPC (Instrument Panel Cluster) to illuminate the air bag warning indicator.

The RCM (Restraints Control Module) analyzes the deployment loop resistance to determine if a fault exists. The value displayed in the PID (Parameter Identification) is the deployment loop resistance measured by the RCM (Restraints Control Module). If the value displayed is lower or higher than the desired range (refer to diagram below), the RCM (Restraints Control Module) can set a DTC (Diagnostic Trouble Code). As the deployment loop resistance drifts farther outside the desired range, the chance for a DTC (Diagnostic Trouble Code) 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 (Parameter Identification) value to be within the desired range before the fault is considered repaired, regardless if the module is reporting an on-demand DTC (Diagnostic Trouble Code) 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:

- Wiring

- Connections

- LH (Left Hand) side air curtain module

- RCM (Restraints Control Module)





DTC Fault Trigger Conditions






Pinpoint Test

WARNING: Do not handle, move or change the original horizontal mounting position of the RCM (Restraints Control Module) while the RCM (Restraints Control Module) is connected and the ignition switch is ON. Failure to follow this instruction may result in the accidental deployment of the Safety Canopy(R) and cause serious personal injury or death.

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.

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 (Supplemental Restraint System) components when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS (Supplemental Restraint System).

NOTE: Always make sure the correct SRS (Supplemental Restraint System) 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 (Supplemental Restraint System) component is installed, DTCs (Diagnostic Trouble Codes) may set.

NOTE: The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.

1. RETRIEVE RCM (Restraints Control Module) DTCs (Diagnostic Trouble Codes)

1. Ignition ON.

2. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was DTC (Diagnostic Trouble Code) B0021:11, B0021:12, B0021:13 or B0021:1A retrieved on-demand during self-test?






2. CHECK THE LEFT CURTAIN DEPLOYMENT CONTROL 1 RESISTANCE (DEPLOY_11_R) PID (Parameter Identification)

1. Using a scan tool, view RCM (Restraints Control Module) PIDs (Parameter Identifications).

2. Monitor and record the resistance value displayed by the DEPLOY_11_R PID (Parameter Identification).

Does the PID (Parameter Identification) value read between 1.7 and 2.78 ohms?






3. CHECK THE LEFT CURTAIN DEPLOYMENT CONTROL 1 RESISTANCE (DEPLOY_11_R) PID (Parameter Identification) WHILE CARRYING OUT THE HARNESS TEST

1. While monitoring the DEPLOY_11_R PID (Parameter Identification), carry out the harness test of the LH (Left Hand) side air curtain module 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 (Parameter Identification).

- Remove the upper C-pillar trim panel. REFER to C-Pillar Trim Panel - Upper. C-Pillar Trim Panel - Upper
- Position aside the upper B-pillar trim panel. REFER to B-Pillar Trim Panel .
- Remove the coat hook and the two headliner retaining pins at the rear of the headliner. REFER to Headliner - 4-Door Sedan or REFER to Headliner - 5-Door Hatchback .
- NOTICE: Use care when lowering any portion of the headliner. Failure to do so can result in creasing the headliner.

Fold the rear seat back down and lower the LH (Left Hand) rear corner of the headliner to access the side air curtain module electrical connector.

Does the PID (Parameter Identification) value read between 1.7 and 2.78 ohms while carrying out the harness test?






4. CHECK THE LEFT CURTAIN DEPLOYMENT CONTROL 1 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 (Restraints Control Module) by inducing a different fault condition. If the reported fault changes, this indicates the RCM (Restraints Control Module) is functioning correctly and is not the source of the fault.

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

3. Disconnect LH (Left Hand) Side Air Curtain Module C9031.

NOTICE: Use care when lowering any portion of the headliner. Failure to do so can result in creasing the headliner.

4. Repower the SRS (Supplemental Restraint System).Do not prove out the SRS (Supplemental Restraint System) at this time. REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

5. Ignition ON.

6. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

7. DIAGNOSTIC TIP: When viewing DTCs (Diagnostic Trouble Codes) with the LH (Left Hand) side air curtain module disconnected, an open circuit fault is normally retrieved.

Did the on-demand DTC (Diagnostic Trouble Code) change from B0021:1A to B0021:13?






5. CHECK FOR A SHORT BETWEEN LH (Left Hand) SIDE AIR CURTAIN MODULE CIRCUITS

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

3. Disconnect RCM (Restraints Control Module) C310A and C310B.

4. Measure:





Is the resistance greater than 10,000 ohms?






6. CHECK THE LH (Left Hand) SIDE AIR CURTAIN MODULE CIRCUITS FOR AN OPEN

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

3. Disconnect LH (Left Hand) Side Air Curtain Module C9031.

NOTICE: Use care when lowering any portion of the headliner. Failure to do so can result in creasing the headliner.

4. Disconnect RCM (Restraints Control Module) C310A and C310B.

5. Measure:





Are the resistances less than 0.5 ohm?






7. CHECK THE LEFT CURTAIN DEPLOYMENT CONTROL 1 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 (Restraints Control Module) by inducing a different fault condition. If the reported fault changes, this indicates the RCM (Restraints Control Module) is functioning correctly and is not the source of the fault.

1. Connect RCM (Restraints Control Module) C310A and C310B.

2. Connect a fused jumper wire:





3. Repower the SRS (Supplemental Restraint System).Do not prove out the SRS (Supplemental Restraint System) at this time. REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

4. Ignition ON.

5. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

6. DIAGNOSTIC TIP: When viewing DTCs (Diagnostic Trouble Codes) with the LH (Left Hand) side air curtain module circuits shorted together, a low resistance fault is normally retrieved.

Did the on-demand DTC (Diagnostic Trouble Code) change from B0021:13 to B0021:1A?






8. CHECK THE LEFT CURTAIN DEPLOYMENT CONTROL 1 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 (Restraints Control Module) by inducing a different fault condition. If the reported fault changes, this indicates the RCM (Restraints Control Module) is functioning correctly and is not the source of the fault.

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

3. Disconnect LH (Left Hand) Side Air Curtain Module C9031.

NOTICE: Use care when lowering any portion of the headliner. Failure to do so can result in creasing the headliner.

4. Repower the SRS (Supplemental Restraint System).Do not prove out the SRS (Supplemental Restraint System) at this time. REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

5. Ignition ON.

6. Using a scan tool, perform RCM (Restraints Control Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

7. DIAGNOSTIC TIP: When viewing DTCs (Diagnostic Trouble Codes) with the LH (Left Hand) side air curtain module disconnected, an open circuit fault is normally retrieved.

Did the on-demand DTC (Diagnostic Trouble Code) change from B0021:11 to B0021:13?






9. CHECK THE LH (Left Hand) SIDE AIR CURTAIN MODULE CIRCUITS FOR A SHORT TO GROUND

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) . Service and Repair

3. Disconnect RCM (Restraints Control Module) C310A and C310B.

4. Measure:





Are the resistances greater than 10,000 ohms?




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