“Check engine” light, Stomp Test for an 1989

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SORIANOTRON
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“Check engine” light, Stomp Test for an 1989

Post by SORIANOTRON »

Hey guys,

Have a weird one for yall....

So the red “check engine” light on the dash (not the “check” light) comes in when I begin to drive.

So I decided to preform a stomp test since I have a mototronic 1.3 (1989 635csi)

Now this is where it gets weird....

After 5 successful pumps on the accelerator, my ANTI-LOCK light will begin to flash!? :-k

I’ve done the stomp test a few times and every time the ANTI-LOCK will flash.

So I am beginning to think maybe the connections got swapped at some point and the CHECK ENGINE light functions the ANTI-LOCK and vice versa.....it could be in the realm of possibility seeing as the previous owner did remove and replace some components in the dash/tach.

Anyone have any type of experience with something like this or have any ideas I can properly diagnose this weird one?

I have attached a video of the stomp test

https://youtu.be/FLr2BdyGTws
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hornhospital
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Re: “Check engine” light, Stomp Test for an 1989

Post by hornhospital »

Definitely looks like the lights are swapped. And it appears you have no codes stored. Can you get it to flash 1444?
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
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SORIANOTRON
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Re: “Check engine” light, Stomp Test for an 1989

Post by SORIANOTRON »

No, can’t get it to 1444

So if my suspicions are confirmed, the “check engine” light is actually the ANTI-LOCK light then my issue is brake related.

I’ll take a look around and keep you guys posted on what I find.
85MSteinway
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Re: “Check engine” light, Stomp Test for an 1989

Post by 85MSteinway »

take it for a ride and stomp on the brakes to see if they lock up. if it is really the ABS then you will lock up the brakes. If you get the pulse you expect from hard braking then I'd say its not ABS.

Jay
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85 M635
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hornhospital
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Re: “Check engine” light, Stomp Test for an 1989

Post by hornhospital »

Isn't that backwards, Jay? Correctly operating ABS brakes at full application will pulse but not lock the brakes or slide the tires. Non-ABS will lock and slide the tires.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
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86_6series
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Re: “Check engine” light, Stomp Test for an 1989

Post by 86_6series »

Jay's statement is starting with bad ABS.
Your statement is starting with good ABS.

Both are correct.
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
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