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Manuel Valdez

Airbag system testing

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Hello,

 

While changing the bulbs from the dash cluster i found out that the airbag light had no bulb, after putting a new one I noticed a solid light; I think that the previous owner had the light and the fix was to remove the airbag module since it isn't one connected under the dashboard; the connectors are zip tied.... I had two theories:

 

  1. The repair cost was excesive for the previous owner and she decided to remove it or
  2. The servie cheated and remove it and deliver it as "fixed"

 

Anyway, I can get a "new" module from a donor, not crashed car, but, I would like to test the airbag system before connecting the module... I want to reduce the risk to automatically deploy the bags at the moment of re connecting the battery after installing the module.

 

Any of you know a way to test the health of the crash system before installing the module?

 

Thank you.

 

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Normally a scan tool can do the diagnosing. There is no other method I would suggest to check the airbag system. It is self checking every key on cycle, so if the problem is fixed - the light will go out.

 

-Dominic

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Hello,

I have the "Ford Service Manual" for the 1995 Contour and mystique.

Section 01-20B Restraints, Passive Supplemental Air Bag System describes the system and the diagnosis/testing procedures. Unfortunatly it is 70 pages and you probably do not need all of them. 

If you give me your email address I can send you the first page which describes what is included in this section and you can tell me precisely what you need.

Pieloux

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Using the service manual without the special service tools or training working on a system that contains low grade explosive charges in the frontal airbags is not a good idea. The airbag system works on resistance, the sensors and the airbags all work on resistance. Any tampering with the wires or connectors could cause other issues - Safety issues. The airbag system is pretty simple, but it's not something for the common DIY'er. You can choose to ignore this information - But it needs to be said to prevent something catastrophic in the future.

 

-Dominic

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I totally agree with you. Testing air bag system requires appropriate (service) tools and is not for the common DIY'er. However, the only interest with the service manual is that it gives you the description and operation of the system and the location of the components.

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Normally, the airbag system will output a code through the airbag light by pulsing it. Quick and long pulses can be read for a code number.

 

-Dominic

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Hello,

 

At th end, I managed to find my Ford Contour/Mystique service manual, it was stored at my grand mothers house about 8 years ago.

 

I found that the test module is just ast its name; a test module, it can't trigger the air bags deployment, this task is done directly by the crash sensors that are directly hard wired to the bags.

 

With this information, I think that it is totally safe to plug the missing test module into the car, of course, the battery has to be disconnected for at least a minute before installing it.

 

Even when in the service manual describes the expected voltages pin by pin, I think that my first step will be to test the system with the test module before taking any further step.

 

As Dominic wrote, it could be dangerous for a hobbyst.

 

 

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Hello,

 

I got the airbag module, it showed the code 21, mostly indicating a bad connection, the manual says how to diagnose it, but before making more, had any of you dealed with this code before?

 

 

 

Edited by Manuel Valdez

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So, code 21 is for the RH front airbag sensor. It's in the right side kick panel next to the PCM. The code states the sensor is not bolted to it's bracket.

 

DTC 21: SAFING SENSOR NOT MOUNTED TO VEHICLE PROPERLY

 

21-1 CHECK FOR DIAGNOSTIC TROUBLE CODE

  • Turn ignition switch to RUN.
  • Count diagnostic trouble code.
Is Code 21 flashing?
Yes No
GO to 21-2 . READ the normal operation description for this diagnostic trouble code.

DO NOT proceed with Pinpoint Test until the code is flashing!

Failure to do so will result in needless replacement of the air bag system components and repeat service.

 

21-2 MEASURE RESISTANCE BETWEEN PIN C234-3 AND PIN C234-16

  • Turn ignition switch to OFF.
  • Deactivate system (leave battery cables disconnected).
  • Disconnect air bag diagnostic monitor.
  • Measure resistance between Pin C234 , Circuit 91 (BK/R, ground and Pin C234 , Circuit 9 (BR/GN).
Is resistance greater than two ohms?
Yes No
GO to 21-3 . REPLACE air bag diagnostic monitor. RECONNECT system. VERIFY system. REACTIVATE system.

 

21-3 MEASURE RESISTANCE IN CIRCUIT 9 (BR/GN)

  • Disconnect RH kick panel safing sensor.
  • Measure resistance of Circuit 9 (BR/GN) in the RH kick panel safing sensor connector to RH kick panel safing sensor sheet metal case ground. The sheet metal case ground must be bare and clean.
Is resistance greater than two ohms?
Yes No
GO to 21-4 . LOCATE and SERVICE open in Circuit 9 (BR/GN). RECONNECT system. VERIFY system. REACTIVATE system.

 

21-4 MEASURE RESISTANCE TO GROUND

  • Remove RH kick panel safing sensor and bracket from vehicle.
  • Thoroughly clean the RH kick panel safing sensor mounting surface.
  • Remount RH kick panel safing sensor and bracket.
  • Measure resistance of Circuit 9 (BR/GN) in the RH kick panel safing sensor connector to RH kick panel safing sensor sheet metal case ground.
Is resistance greater than two ohms?
Yes No
REPLACE RH kick panel safing sensor and bracket. RECONNECT system. VERIFY system. REACTIVATE system.

RECONNECT system. VERIFY system. REACTIVATE system.

 

 

 

Hope this helps.

 

-Dominic

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