Check engine light question

[Jean]

Hello,

I have an early 318 car and need to install a check engine light. How is the check engine light circuit hooked up in the late model cars?

I am wondering if I can ADD a light to my early cluster OR if I have to swap to another cluster and run some wires for the bulb?

Reason why I have to do this is for my b35 swap, BAR will look for the check engine light that my car currently does not have.

Thanks!

[Jean]

anyone?

For starters, when you turn the key in does the check engine light come on like the battery/oil pressure light?

When you start the car, the light turns off yes?

[Jean]

ETM shows that the "Check" light is pin 4 which is WT/BK wire...but does it go to the Active Check Control panel? I hope that's not something I need to add into my car.... argh.

[yert315]

the CEL comes on in the 'accessory' key position and turns off when the car is started (unless there is a fault of course). Sorry, this is all I can help you with!

[Jean]

Here is what I found out so far from the 89 325i ETM.

I looked at the 89 325i ETM and the "Check" active check control lamp indicator inside the cluster is connected to pin 4 (C1 WHITE connector) via WT/BK wire that points to "ACTIVE CHECK CONTROL". Page 66.

Then page 71 for Active Check Control shows the "Active Check Contro "Check Light"" connected on one side pin 23 at C1 to the fuse 10 (hot in run or start) via GN/WT wire at junction S212 (need to find where that is)...and the other end pin 4 WT/BK (this must be from the cluster) to pin 2 of the Active Check Control Unit.

Pin 2 inside the Active Check control Unit goes to "Alarm control" block diagram.... wtf bbq.



My question is, actually a couple.

1) does the "active check control" = the onboard check panel?
2) is it possible to have a working check engine light in the cluster w/o the check panel?

Anyone?

[Japandrew73]

You know what you should do, and what I'll probably end up doing, is if you still have the seatbelt warning light mounted on your dash, you should make a check engine light that lights up in that. If not, utilizing one of the extra lights next to the fog light lights on your cluster for a check engine light instead would work neatly and functionally i'd think

[Fidhle007]

The CEL light and the "Check" light are different. The former is just a simple bulb in the bottom of the cluster. You'll find it in the "Injection Electronics" section of the ETM, a few pages down. It grounds out to the ECU via C101, should be simple enough to connect.

[Jean]

Fidhle - I thought the light dead in the center of the cluster is the check engine light? Where is the CEL light? I have an 89 325i cluster and it's got the fog light, park brake, brake lining, brake fluid, antilock, battery, oil... and the "check" light above the SI board lights.

To make this clear, I am after the "check engine" or I guess "CEL" light that would come on if the ECU/Engine throws a code or whatnot.

It's for CA BAR reasons.

[Fidhle007]

The light you're thinking of flashes when something comes on on the Check Panel. The "Check Engine" light (or CEL) is on the bottom towards the right next to the "Brake Lining" light. Hold a work light up behind it and you'll see it.

[Jean]

I see it, on this 89 cluster it's all the way on the LEFT, second from the left actually. Wow, had no idea man!

So this light on a working car comes on when you insert the key yes?

Alright, so this makes it easier, now I just need to figure out how to add that light to my swap/harnes. Otherwise I can just wire it with the battery/oil pressure lol...

Thanks dude!

[Fidhle007]

I meant left, oops! Yeah, there it is. It will come on in RUN and then go off when the engine is started. It will not come on in ACC. like was previously mentioned. Unless of course you have a code, then it will be on when the car is running too...

[Jean]

Gotcha, thanks dude! Come on in RUN means I can't run it off the battery/oil pressure lights.... doh.

Back to e34 91 ETM :)

[Fidhle007]

Maybe I'm thinking of the first click as ACC. The power source could probably be the same as the battery/oil lights, but the ground will go to the ECU.

[Fidhle007]

No wait, scratch that, those are hardwired to the cluster. It could share with "Brake Lining" I think though, but your best bet is probably just to find some switched power and let the ECU do all the work.

[Jean]

I could solder it in, if I knew for sure when it needs to come on and off. I am still looking through the ETM to find what pin of the ECU controls the bulb...