Instrument cluster question

[Little-Lack]

Hi All,

New to the forum, i recently purchased a 1998 Z3 M44 for the grand sum of £760.00... so it was bound to have a few... OK a lot of issues..

Knowing this i have been slowly taking the car to bits to look into restoring this back to as near perfect as i can get it!

But here is my first of likely many questions to come over the next few months

I removed the Instrument cluster on Sunday to replace the front bezel of these with a newer nicer chrome looking set (the strip down was straight forward enough) i didn't want to replace my clocks as i wanted to keep the true millage.

However i noticed something a little odd on the rear of the clocks.... someone in the past has installed a link cable between the Airbag warning light and the ABS warning light on the back of the clocks??

Anyone got any idea why they would have don't this? I haven't removed the link at this stage but I'm guessing it may well have something to do with the bypassed wiring i also found under the drivers seat!!

Sorry i stupidly didn't take any pic of this

 

[Stevo7682]

You need to get your zed plugged into a code reader buy from what you are saying sounds like you have an airbag fault on some sort and someone has botched it to put light out.
If this is the case the fault will still be there code reader should point in the right direction but it also means if this is the case your airbags are currently non functioning and will not deploy in an accident if required.

Stephen.

 

[Little-Lack]

You need to get your zed plugged into a code reader buy from what you are saying sounds like you have an airbag fault on some sort and someone has botched it to put light out.
If this is the case the fault will still be there code reader should point in the right direction but it also means if this is the case your airbags are currently non functioning and will not deploy in an accident if required.

Stephen.

Thanks Stephen,

I thought this maybe the case, looking under the seat it looks like they have bypassed some of the wiring as the seat motor is in connector block and not the standard BMW connector, no signs the cars been in any bumps but on this age its hard to tell i guess!

Sorry to ask but are airbag faults pretty standard on these?

I will order a code reader up seen one on amazon for about £40.00.

 

[Stevo7682]

The pre tensioner cables under the seats ( leading to the belt stalk ) can get damaged.
If ignition turned on when seats are out also causes air bag fault.

The code reader should help diag the issue.
You will also need a 16 to 20 pin obd cable like this .

As on the zed 3 pre face-lift zeds do not have a 16 pin plug face-lift models do under steering but only really engine and abs diag available from this ( even then not full ) full diagnostic requires use of the 20 pin obd plug in the engine bay.

Stephen.

 

[t-tony]

If you turn on the ignition, without starting the engine, does the Airbag (SRS) warning light come on and then extinguish after a few seconds? If it does this then as far as the MOT test is concerned it is doing it's job. However, as Steve says the Airbags may not be operable in the event of a collision. The wiring under the seat could well be a red herring if the original seats have been swapped for some from a later model.

Tony.

 

[t-tony]

The 16 pin OBD under the dash only talks to engine and Auto Gear box ECUs.

Tony.

 

[Little-Lack]

Guys thank you for this, I will get these orders up from amazon now and start some deeper digging!

 

[jonco]

If you turn on the ignition, without starting the engine, does the Airbag (SRS) warning light come on and then extinguish after a few seconds? If it does this then as far as the MOT test is concerned it is doing it's job. .............

You may have already picked up on this but the airbag light has a dual illumination source - either bulb or LED.
There are many stories of this system being bodged - in the case of my car, I found quite by accident, the bulb had been removed and black silicone sealant injected to blackout the warning light. The car had actually passed the MoT because the tester had not checked the test function which Tony describes in his comment.
In addition to underseat wiring the plugs/sockets on belt pre-tensioners need checking/cleaning and they should be secured together with cable ties. As Stephen has said code reader required to identify and reset error code. HTH

 

[colb]

Be aware that 1998 cars have a different diagnostic OBD1 as opposed to 1999 cars that changed to OBD2. I have had problems scanning the early cars as they need a laptop with an old style serial port and cable to use with laptop software such as BMW INPA. Always use the 20pin engine bay diagnostic socket which will connect to all the modules on the car. If you have a 16pin OBD socket under the steering wheel that will only read the engine and transmission modules. Not at all sure if some of the handheld code readers will connect to the early models.
I have a December 1999 1.9 and that has OBD2 so works with laptop software via a usb connection for INPA and BMW Scanner 1.4, it also works with a Creator 310+ handheld reader.

 

[jonco]

..... I have had problems scanning the early cars as they need a laptop with an old style serial port and cable to use with laptop software such as BMW INPA.................

Confusing change-over period - I have 98 model (12/97 build) which only has 20 pin under bonnet. I can read all modules on an old Windows laptop using INPA apart from Instrument cluster which I was told needs serial port and some other kit.