Hi all, My father has a Mondeo mk3 21tr diesel 2006

He has written down the problem he has:

air-bag light on permanently (no codes flashing)

Seat belt warning not sounding

Diagnostic check shows no communication established. possible causes

1 ignition was not on

2 battery voltage was low or ecu not present

3 cables not connected correctly

Have fitted used (good) air-bag sensor from 2005 car but fault remains.

Thanks for any advise, Johnathan.

Check the connectors under the front seats are secure and wiring is not damaged.

Another reason diagnostics may not connect.. if the car's a diesel then they started using OBDII later than petrols.

Check for the presence of the OBD port's fuse.

Have the seats ever been removed and then the ignition turned on? As that would trigger the airbag light

My 05 Mondeo ST TDCi was OBD 2 compliant.

My 05 Mondeo ST TDCi was OBD 2 compliant.

Just putting it out there... As for example, our 2003 Renault Laguna Dynamique 1.9 diesel is Not OBD2 Compliant! :)

It's French ! :)

It's French ! :)

And a PITA as most French made items ;)

Yep. . . Froggy kak, , the OP's Mondeo will be OBD II / EOBD compliant, as should the French tin can. :)

Regardless of wether diagnostics will connect or not, most diags dont do airbag dtc reading, lots of possible causes why air bag on. Needs a proper code reader for airbag putting on , then you will know quickly what area you are looking at.