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Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

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Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Old 06-13-2019, 04:43 AM
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Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Hi everyone,

I've been reading and learning a lot in this great forum, but stumbled upon a problem I couldn't find a solution for. So here goes my first post.

Im living in Germany and bought a 84 Camaro 2.8l V6 with a 4 Speed Automatic Transmission around a year ago.
It was running fine till a few weeks back, when it stopped turning over. I detected a faulty ICU, imported a new one, replaced it and the car started right up. All was fine again for about 400 km/250 miles.

Until this morning. I turned the Key to "ON" and the usual buzzing of the seat-belt-buzzer appeared. But it didn't stopped, even after a one or two minutes of waiting. Also, my "Check Engine"-light was glowing all the time. When I tried to start the car and turned the key to "IGNITION" nothing happend. Only the buzzing sounded a bit weaker/quieter.
So I tried to pull the engine error codes with the paper clip method. I sticked the clip into pins A & B. I put my key back in, turned it to "ON". The engine light immediately startet flashing continuously, in 1sec intervalls. I also heard click-sounds comming from the engine bay in the exact rythm the engine light was flashing. I traced the sound back to the radiator fan relay, pulled it, and the relay next to it (fuel pump?) started clicking. Don't know if thats supposed to mean anything.
I wasn't able to pull any codes from the car.

At first I thought the Camaro was in Field Service Mode (hence the flashing) but since the engine is not running (nor cranking) thats not possible, right?

Any ideas where I should start looking? Is my ECM maybe breaking down? Or could this be connected to bad grounding? Importing spare parts is relatively expensive so I'd like to try to narrow it down.

Any help is much appreciated, thanks!
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Old 06-13-2019, 06:30 AM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Originally Posted by Arne Ebner View Post
Hi everyone,

I've been reading and learning a lot in this great forum, but stumbled upon a problem I couldn't find a solution for. So here goes my first post.

Im living in Germany and bought a 84 Camaro 2.8l V6 with a 4 Speed Automatic Transmission around a year ago.
It was running fine till a few weeks back, when it stopped turning over. I detected a faulty ICU, imported a new one, replaced it and the car started right up. All was fine again for about 400 km/250 miles.

Until this morning. I turned the Key to "ON" and the usual buzzing of the seat-belt-buzzer appeared. But it didn't stopped, even after a one or two minutes of waiting. Also, my "Check Engine"-light was glowing all the time. When I tried to start the car and turned the key to "IGNITION" nothing happend. Only the buzzing sounded a bit weaker/quieter.
So I tried to pull the engine error codes with the paper clip method. I sticked the clip into pins A & B. I put my key back in, turned it to "ON". The engine light immediately startet flashing continuously, in 1sec intervalls. I also heard click-sounds comming from the engine bay in the exact rythm the engine light was flashing. I traced the sound back to the radiator fan relay, pulled it, and the relay next to it (fuel pump?) started clicking. Don't know if thats supposed to mean anything.
I wasn't able to pull any codes from the car.

At first I thought the Camaro was in Field Service Mode (hence the flashing) but since the engine is not running (nor cranking) thats not possible, right?

Any ideas where I should start looking? Is my ECM maybe breaking down? Or could this be connected to bad grounding? Importing spare parts is relatively expensive so I'd like to try to narrow it down.

Any help is much appreciated, thanks!
The starter isn't cranking at all? Since the buzzing got quieter while trying to crank I would assume the starter circuit is working like normal, you could confirm with a voltage drop test, or test light on the s terminal of the starter. Check battery voltage and your cable connections on the battery. I don't have much V6 experience, but what did it have in 84? multi port, TBI, or is it carb with computer controlled ignition?

Just a FYI, I have a complete dropout 5.3 LS motor here in Germany for sale...What part of Germany are you in?
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Old 06-13-2019, 09:35 AM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Jep, no cranking at all.
I will try to check the starter & battery today or tomorrow. Battery seemed fine when I installed the new ICU but who knows...

The engine is a LB8 V6 with multiport fuel injection which is a little confusing, since it was introduced in 85. So maybe the notes of the previous owner are wrong and the car was actually build in 85. Have to check that again when I get home tonight, never noticed it before.

I'm living in Bonn, thanks for the offer! But I think an engine swap is above my budget right now
But I'm curious, so if you like PM me the price and I will think it through! Thanks!
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Old 06-13-2019, 09:46 AM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Yeah the ECM doesn't control cranking. Crank circuit is very simple. Fix that and your problem will likely be resolved.

GD

Last edited by GeneralDisorder; 06-13-2019 at 11:59 AM.
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Old 06-13-2019, 10:32 AM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Also I noticed the fuel pump is not priming. Could this also be connected to the crank circuit?
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Old 06-13-2019, 11:58 AM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Yes - you may have a power supply problem which could certainly affect multiple systems. I would start with the crank circuit and likely the fuel pump issue will be resolved at the same time. Check for power to the starter solenoid while you have an assistant hold the key in the crank position. Use an incandescent test light so you know the circuit can carry current.

GD
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Old 06-13-2019, 02:59 PM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Ah okay, thank you very much for the info!

I have a few hours on the weekend and will let you know how things turn out!
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Old 06-15-2019, 03:30 PM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

When VATS malfunctions the fuel pump is cut off, to prevent the car from being stolen. Bypassing VATS is very common and there are threads on how to temporarily bypass the VATS to see if that's what the issue is. These cars tend to have VATS problems over time. My car's VATS simply stopped working one day and the starter was disengaged as a result.

If all else fails, try bypassing the VATS [relay?] and then attempt to crank the engine. If it cranks, then that was the issue. You can temporarily bypass it by jumping it with a small piece of 14ga wire, no permanent cutting required. Message me if you want to attempt this.
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Old 06-15-2019, 04:00 PM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

No VATS in 84.

GD
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Old 06-15-2019, 04:20 PM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!




Yep , crazy simple crank circuit , The ignition switch , the neutral safety switch , and the solenoid itself . Have you checked the fusible link ?
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Old 06-15-2019, 04:30 PM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

PS , the above diagram is what's listed for a 1984 2.8 V6 . Interesting that it's not MPFI , as the original poster says his car is . Either way , VATS didn't happen till 1989 , so the above diagram should be a good representation of the OP's car , starting wise .
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Old 06-17-2019, 07:19 AM
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Re: Car won't crank, constant Engine Light flashing, No Codes, Bad ECM?!

Okay guys, I feel a little stupid now - it was just the battery.

I jumpstarted the camaro with my girldfriends car and all was well. I'm just wondering why the battery was down to 4 Volt. The alternator seems to work fine and putting out a solid 13 to 14 Volt.
Maaaaybe I didn't turn off the radio after my last drive (it's an aftermarket the previous owner installed and does not shut down after you pull the key). Or there is some other gizmo going on, I will keep a close eye on the state of charge of my battery.

Thanks again for your help guys, I just overreacted seeing my car in this state!
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