Engine shuts down
Thread Starter
5th Gear
Joined: Jul 2018
Posts: 5
Likes: 1
From: Oronoco, M N
[QUOTE=wbjork41;1597684705]"Yes, but I have had it fully tested by O'Reilly Auto Store. It tested fine. After the engine shuts down and I try to start it again it won't crank over but I noticed the voltage goes down to 3 volts for 20 seconds and pops back to 12V. I let the car set for a 1/2 Hr and it stats up and runs fine with the error codes. Knock sensors and reduced engine power 1682 code.
Thread Starter
5th Gear
Joined: Jul 2018
Posts: 5
Likes: 1
From: Oronoco, M N
Does anyone know if 1682 will just reduce the engine power to 1/2 power or will it shut the engine down or what actually turns the engine off. I have read that ignition switch fault causes this problem and one person has changed theirs but no indication if this actually fixed the problem. Any ideas would be greatly appreciated. Thanks
Le Mans Master
Joined: May 2000
Posts: 8,729
Likes: 1,508
From: Redmond WA
Does it set a code? If so, there will be an OBD2 snapshot of everything else that was going on at the time, which should help them ID the cause.
If not (ie: no code) then I'm going to guess electrical.
I think it's a safe bet that GM will NEVER turn off an engine for you. If they don't do it for no oil pressure, they're not doing it for anything else. It'll run till rods hang out the block if needed, but the ECM will NOT power it down.
If not (ie: no code) then I'm going to guess electrical.
I think it's a safe bet that GM will NEVER turn off an engine for you. If they don't do it for no oil pressure, they're not doing it for anything else. It'll run till rods hang out the block if needed, but the ECM will NOT power it down.
Thread Starter
5th Gear
Joined: Jul 2018
Posts: 5
Likes: 1
From: Oronoco, M N
Thanks Dave ... the OBD2 code is 1682 and the description is as follows:
The ignition voltage circuit is between the powertrain relay and the ECM. The ignition voltage circuit is a feedback circuit.
High resistance in the circuit/understood fuse block for either the power train relay or the run/crank relay can cause DTC P 1682 to set.
So it would appear you analysis is correct I need to look for the electrical problem that would kill the ignition switch and or disable the crank capabilities.
Thanks again for your help!!
The ignition voltage circuit is between the powertrain relay and the ECM. The ignition voltage circuit is a feedback circuit.
High resistance in the circuit/understood fuse block for either the power train relay or the run/crank relay can cause DTC P 1682 to set.
So it would appear you analysis is correct I need to look for the electrical problem that would kill the ignition switch and or disable the crank capabilities.
Thanks again for your help!!
Le Mans Master
Joined: May 2000
Posts: 8,729
Likes: 1,508
From: Redmond WA
If it's intermittent, it's harder to find, but it's likely a bad connection at the main relay or fusebox, I'd guess. Something didn't get tightened at the factory, or a bad crimp...
In my 69 Pontiac that my Dad bought new they fought a problem with the ALT light (charge) coming on for years. When I restored the car 25 years later I found a badly crimped terminal on the back of the main fusebox, so if you moved the harness around (like going over a big bump) it'd make or break connection. So they can be hard to find!
In my 69 Pontiac that my Dad bought new they fought a problem with the ALT light (charge) coming on for years. When I restored the car 25 years later I found a badly crimped terminal on the back of the main fusebox, so if you moved the harness around (like going over a big bump) it'd make or break connection. So they can be hard to find!
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Instructor
Joined: Apr 2018
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Sounds like either a loose/bad connection, or a bad battery.
I know you had it tested, but the load testing isn't foolproof. When you try to start it and the voltage drops to 3V - that's a telltale sign of a bad battery. I'm assuming you're using a real voltage meter, and not relying on the electronic dash reading.
I know you had it tested, but the load testing isn't foolproof. When you try to start it and the voltage drops to 3V - that's a telltale sign of a bad battery. I'm assuming you're using a real voltage meter, and not relying on the electronic dash reading.
