Question for T4 operators.

[Rovering]

Hi all.
I have still got a 'short' reading for both my ITS airbags and the drivers airbag.
I have obtained a replacement YWC 107090 DCU and am wondering if it is a 'plug and play' replacement or if it needs to be configured with a T4?
Can someone please advise.
Cheers,
Graeme

[Phil-T4]

I have still got a 'short' reading for both my ITS airbags and the drivers airbag.

NEVER EVER measure the resistance of air bags

I have obtained a replacement YWC 107090 DCU and am wondering if it is a 'plug and play' replacement or if it needs to be configured with a T4?

If the replacement came from a car with an identical SRS specification and body type then it will work and only have a VIN mismatch.


.

[marinabrian]

As the airbag internal resistance is circa 2.3 Ohms, a conventional meter will see this as a virtual short circuit.

As Phil says under no circumstances whatsoever attempt to measure the resistance of an airbag, as when measuring resistance a reference voltage is present across the probes of the multimeter.

It does well to note that the explosive charge within the airbag is detonated using a voltage supply !!!!!

Brian

[Rovering]

Sorry, I should have said how I obtained those messages.
They were obtained from my garages computer, of whatever system they use.


0x9007 short circuit fault in driver airbag circuit.
0x9043 short circuit fault in LH I.T.S circuit
0x9047 short circuit fault in RH I.T.S circuit.

As these came up after I put the carpet, dash and seats back in, I wondered if I had somehow fried the DCU in the process.
Graeme

[SD1too]

Hello Graeme,

I currently allegedly have a "short" (according to T4) in my driver's airbag circuit so I'm learning as much as I can about this system.

MG Rover says that the DCU must be securely and carefully positioned on its mounting surface. Apparently any gaps can cause problems, so if you removed your DCU during your recent work you might like to check that.

I also read that if the DCU develops an internal fault it shuts down the entire airbag system and you don't appear to have evidence of that.

Simon

[Rovering]

Originally Posted by SD1too

Hello Graeme,

I currently allegedly have a "short" (according to T4) in my driver's airbag circuit so I'm learning as much as I can about this system.

MG Rover says that the DCU must be securely and carefully positioned on its mounting surface. Apparently any gaps can cause problems, so if you removed your DCU during your recent work you might like to check that.

I also read that if the DCU develops an internal fault it shuts down the entire airbag system and you don't appear to have evidence of that.

Simon

Thanks Simon.
I only unplugged the connector from the DCU. Did not do anything else to that part.
I am going to try taking the seats out again and check all the connectors, also am going to try the other side impact sensor I have. I may also have to end up taking the centre console out again too, just to check I have not squashed/caught any wiring anywhere.
Jolly nuisance!
Graeme

[drewbie]

Originally Posted by Phil-T4

NEVER EVER measure the resistance of air bags



If the replacement came from a car with an identical SRS specification and body type then it will work and only have a VIN mismatch.


.

Can anyone please confirm the resistance of Rover 75 airbags, it would be useful to have the correct resistor to hand when fault finding.

[Phil-T4]

A 2R2 will do

[madeupname]

Pardon my ignorance, but what is a DCU?
I'm changing seats and need to know if this is something I need to beware of.
Thanks

[SD1too]

Originally Posted by madeupname

Pardon my ignorance, but what is a DCU?

Odd isn't it? MGR calls the air bag control unit a Diagnostic Control Unit. Phil-T4 might be able to explain why. I can't see the difference between that and, say, the ECM which must have diagnostic capability since it stores its own fault codes.

Simon