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Have a 57 plate c-max 2.0 TDCI 6months old and its in the garage for the 3rd time!Same problem, air bag warning light is on. First time light came on it was intermittent and of course garage couldnt find a fault with it. Problem was still there so on second visit to garage they found the fault and changed one of the side air bag systems. The warning light is now on again and its back in the garage. Has anyone else had this problem?
 

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Not yet fortunately.
The air bags are set to deploy when the appropriate sensor measures a deceleration greater than a particular figure
The following is from the 2003 TIS disc so excuse a very long post


Diagnosing Customer Concerns Without Hard DTCs/LFCs<?: prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" />
WARNING:
To avoid accidental deployment, the air bag control module backup power supply must be depleted. Wait at least one minute after disconnecting the battery ground cable(s) before commencing any repair or adjustment to the supplemental restraint system (SRS), or any component(s) adjacent to the SRS sensors. Failure to follow these instructions may result in personal injury.

Note:
Following the pinpoint tests when a diagnostic trouble code (DTC) is not present, or the air bag warning lamp is not permanently illuminated, will result in needless replacement of air bag system components and repeat repairs.

Speak with the customer to determine if a particular set of conditions must be met in order for a fault to occur. If an illuminated air bag warning lamp is reported by the customer but is not present when the vehicle comes in for repair, pinpoint test diagnostics cannot be used.

Diagnosing Customer Concerns with Hard DTCs/LFCs
WARNING:
Do not use substitute air bag simulators when working on the supplemental restraint system. Use only the appropriate tool. Failure to follow these instructions may result in personal injury.

Most air bag system diagnostic procedures require the use of system deactivation and system reactivation procedures. These procedures require the air bag module(s) and safety belt buckle pretensioners to be disconnected from the SRS, thereby removing the risk of air bag deployment while diagnostics are carried out.

Air bag simulators are required to carry out diagnosis and testing of the air bag system. The simulator contains a resistor, used to simulate an air bag module connection to the system. It is not acceptable to short-circuit the air bag module connections with a 0 ohm jumper wire. If a 0 ohm jumper wire is used to short-circuit the air bag module connections, an illuminated air bag warning lamp will be displayed and a DTC logged by the restraints control module.

Deactivation
WARNING:
To avoid accidental deployment, the air bag control module backup power supply must be depleted. Wait at least one minute after disconnecting the battery ground cable(s) before commencing any repair or adjustment to the supplemental restraint system (SRS), or any component(s) adjacent to the SRS sensors. Failure to follow these instructions may result in personal injury.

1. Disconnect the battery ground cable. For additional information, refer to «Section 414-01».[Battery Disconnect(414-01 <?: prefix = st1 ns = "urn:schemas-microsoft-com:eek:ffice:smarttags" /><st1:place w:st="on">Battery</st1:place>, Mounting and Cables,genproc)]

2. Wait at least one minute for the backup power supply in the restraints control module to deplete its stored energy.

WARNING:
To minimize the possibility of premature deployment, live air bag modules must only be placed on work benches which have been ground bonded and with the trim cover facing up. Failure to follow these instructions may result in personal injury.

3. Remove the driver air bag module from the vehicle.

4. Connect the air bag simulators to the sub-harnesses in place of the driver air bag module at the top of the steering column.

5. Disconnect the passenger air bag module electrical connectors.

6. Connect the air bag simulators to the wiring harnesses in place of the passenger air bag module.

7. Disconnect the side air curtain module electrical connector on both sides.

8. Connect the air bag simulators to the wiring harnesses in place of the side air curtain modules.

9. Disconnect the driver underseat air bag electrical connector.

10. Connect the air bag simulator to the driver underseat air bag electrical connector in place of the safety belt pretensioner and side air bag module.

11. Disconnect the passenger underseat air bag electrical connector.

12. Connect the air bag simulator to the passenger underseat air bag electrical connector in place of the safety belt pretensioner and side air bag.

13. Connect the battery ground cable. For additional information, refer to «Section 414-01».[Battery Disconnect(414-01 <st1:place w:st="on">Battery</st1:place>, Mounting and Cables,genproc)]

Reactivation
WARNING:
The air bag simulators must be removed and the air bag modules reconnected when reactivated to avoid non-deployment in a collision. Failure to follow this instruction may result in personal injury.

1. Disconnect the battery ground cable. For additional information, refer to «Section 414-01».[Battery Disconnect(414-01 <st1:place w:st="on">Battery</st1:place>, Mounting and Cables,genproc)]

2. Wait at least one minute for the backup power supply in the restraints control module to deplete its stored energy.

3. Remove the driver air bag simulators from the sub-harnesses at the top of the steering column.

4. Connect and install the driver air bag module.

5. Remove the passenger air bag simulators from the passenger air bag module harnesses.

6. Connect and install the passenger air bag module.

7. Remove the side air curtain simulators from the side air curtain module wiring harnesses.

8. Connect and install the side air curtain modules.

9. Remove the driver underseat air bag simulator.

10. Connect the driver underseat air bag electrical connector.

11. Remove the passenger underseat air bag simulator.

12. Connect the passenger underseat air bag electrical connector.

13. Connect the battery ground cable. For additional information, refer to «Section 414-01».[Battery Disconnect(414-01 <st1:place w:st="on">Battery</st1:place>, Mounting and Cables,genproc)]

14. Prove out the system.

Glossary
Air Bag Simulator
Air bag simulators are used to simulate air bag module connections to the system.

Deactivate the System

Deactivate the system means to carry out the deactivation procedure. REFER to Deactivation in this section.

Prove Out the System
The air bag warning indicator will illuminate for three seconds. If there is a fault condition, the air bag warning indicator will stay illuminated or illuminate after a five second delay.

Reactivate the System

Reactivate the system means to carry out the reactivation procedure. REFER to Reactivation in this section.

Principles of Operation
Supplemental Restraint System (SRS) Operation

The vehicle is equipped with a DC fired sensing system.

In the event of a severe frontal or three-quarter frontal impact, in excess of a predetermined limit the driver and passenger front air bags and safety belt buckle pretensioners will deploy.

In the event of a severe full side impact, in excess of a predetermined limit either the driver or passenger side air bag, side air curtain (if equipped) and both safety belt buckle pretensioners will deploy.

Air bag deployment will only occur, in the event of a severe collision when the ignition key is in the RUN position. The passenger air bag disable (PAD) switch (if equipped) will deactivate the passenger air bag, passenger safety belt buckle pretensioner and passenger side air bag in the event of a severe frontal or side impact; it will not deactivate the passenger side air curtain.

Restraints control module
The restraints control module retains full control of the whole system, providing continual system checks and full diagnostic capabilities. The non-volatile memory stores the fault codes, which can then be downloaded through the data link connector (DLC) to WDS.

In the event of a failure in the vehicle supply during an accident, the restraints control module provides a backup power supply, sufficient to deploy the air bag(s) for a minimum of 150 ms. The backup power supply is discharged by the restraints control module within 60 seconds of the battery ground cable being disconnected. Thus making sure the supplemental restraint system remains operational.

The restraints control module contains electronic acceleration sensors which measure the longitudinal acceleration and the lateral acceleration and provide both signals to the micro-controller proportional to the amount of acceleration measured. When these sensors sense an impact in excess of a predetermined limit, and the crash sensor or side impact sensor sends a signal to the restrains control module, the restraints control module initiates the circuit to deploy the air bag(s). The restraints control module also contains a safing sensor which enables the front air bags and the safety belt buckle pretensioners in the event of a front impact. The safing sensor also prevents unintentional deployment of the front air bags and safety belt buckle pretensioners in the event of a fault in the electronic acceleration sensor(s).

Front Crash Sensor
The front crash sensor contains an acceleration sensor, filter, amplifier and an application specific integrated circuit for signal transmitting and is mounted on the hood latch panel. The front crash sensor sends a signal at a level determined by the crash severity to the restraints control module. The restraints control module will evaluate the signal against stored data and deploy the frontal air bags and safety belt buckle pretensioners if required. Both the front crash sensor and the internal restraints control module longitudinal acceleration sensor must exceed a preset limit to initiate the air bag.

Side Impact Sensor
The side impact sensors are mounted at the base of the B-pillar on either side of the vehicle, to facilitate remote lateral impact sensing. Each side impact sensor contains an acceleration sensor, filter, amplifier and an application specific integrated circuit for signal transmitting. In the event of an impact, in excess of a predetermined limit, the side impact sensor sends a signal at a level determined by the crash severity to the restraints control module. The restraints control module will evaluate the signal against stored data, to deploy the side air bag on the side the deployment request was initiated. Both the side impact sensor and the internal restraints control module lateral acceleration sensor must exceed a preset limit to initiate the air bag. The restraints control module retains control of the side air bags, side air curtains and safety belt buckle pretensioners.

Air Bag Warning Indicator
The air bag warning indicator is incorporated into the instrument cluster, together with the automatic detach detect circuit. The air bag warning indicator illuminates for three seconds at key ON. If the system self-tests OK the indicator extinguishes, if there is a fault condition, the air bag warning indicator will stay illuminated or illuminate after a five second delay.

The system is designed to illuminate the air bag warning indicator continuously if the restraints control module circuit is broken, either by loss of power or ground supply, or module disconnect, or BUS failure. The restraints control module retaining bolts are part of the ground circuit.

Diagnostic evaluation of the SRS can be made through the data link connector (DLC) and WDS to establish the nature of the concern. Once the DTC is known the appropriate course of action can be selected from the Symptom Chart.

Inspection and Verification
1. Verify the customer concern by operating the system.

2. Visually inspect for obvious signs of mechanical or electrical damage.

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

4. If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool menu.

5. Retrieve the DTCs and refer to the Symptom Chart.

Symptom Chart
Note:
It is only allowed to repair circuits between connectors. If damage has occurred within a connector a new wiring harness must be installed. Connectors must not be disassembled.

Condition(s):
o No communication with the module
Possible Source(s):
§ DLC.
§ Circuit(s).
§ Restraints control module.

Action(s) to take:
§ Go to «Pinpoint Test A»

o DTC B1046: Driver side air curtain cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test B»

o DTC B1047: Driver side air bag cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test C»

o DTC B1048: Passenger air bag first stage cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test D»

o DTC B1049: Passenger safety belt pretensioner cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test E»

o DTC B104B: Driver side impact sensor cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test F»

o DTC B104C: Passenger side impact sensor cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test G»

o DTC B104D: Front crash sensor cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test H»

o DTC B104E: Driver side impact sensor short to ground or battery
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test I»

o DTC B104F: Passenger side impact sensor internal fault
Possible Source(s):
§ Side impact sensor.
Action(s) to take:
§ INSTALL a new side impact sensor. REPEAT the self-test, CLEAR the DTCs.

o DTC B1050: Passenger side impact sensor short to ground or battery
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Go to «Pinpoint Test J»

o DTC B1051: Driver side impact sensor internal fault
Possible Source(s):
§ Side impact sensor.
Action(s) to take:
§ INSTALL a new side impact sensor. REPEAT the self-test, CLEAR the DTCs.

o DTC B1054: Driver safety belt pretensioner cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test K»

o DTC B1055: Passenger side air bag cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test L»

o DTC B1056: Passenger side air curtain cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test M»

o DTC B1057: Driver air bag first stage cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test N»

o DTC B1058: Driver air bag second stage cross link to another firing circuit
Possible Source(s):
§ Circuit(s).
Action(s) to take:
§ Note:
Check for a matching 'cross link to another firing circuit' DTC before carrying out pinpoint test.
Go to «Pinpoint Test O»

o DTC B1059: Passenger air bag second stage cross link to another firing circuit
Possible
 

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Hi Vanessa, <?: prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" />
Yes my wife's car has had this problem.
Under the seat is a cable coming from the floor to the front of the seat for the seatbelt warning and SRS system. This should have a cable-tie to fix it at the seat end. It the case of Lynne's car this had not be tightened in manufacture and slipped and I think over time the wires stretched when the seat was adjusted and the connection has become faulty.
The trouble is that his cable is part of the loom, as this necessitates replacing the whole loom at a cost of parts and labour of £1118 !!

Despite being out of the 3-year warrenty Ford have said they will help with part of the costs butwe still basically cannot afford it and I am left with the choice of leave it as it is or try and repair it myself, both of which are dangerous
 
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