P1682
Thread Starter
7th Gear
Joined: Sep 2020
Posts: 7
Likes: 0
P1682
Getting code P1682 on a 47,000 mile 2008 base Corvette Coupe. Cranks but no start.
Checked and load tested battery and also installed a new tested battery.
Cleaned main battery cable terminals and checked starter/solenoid connections as well.
Disconnected battery overnight as well and issue persists.
Fuel pump runs at 52psi with ignition on and 58psi while cranking.
Currently diving into the fuse boxes and was hoping to narrow down which ones to check first (ignition, battery related fuses all check out).
All guidance is greatly appreciated as this daily driver is needed Tuesday morning.
Thank you all.
Checked and load tested battery and also installed a new tested battery.
Cleaned main battery cable terminals and checked starter/solenoid connections as well.
Disconnected battery overnight as well and issue persists.
Fuel pump runs at 52psi with ignition on and 58psi while cranking.
Currently diving into the fuse boxes and was hoping to narrow down which ones to check first (ignition, battery related fuses all check out).
All guidance is greatly appreciated as this daily driver is needed Tuesday morning.
Thank you all.
Retired & lovin' it!
Joined: Mar 2005
Posts: 4,472
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From: Jackson NJ
Melting Slicks
Joined: Apr 2019
Posts: 2,495
Likes: 1,163
From: Northern Wisconsin
Paul, I think you did a good job of determining that your battery and fuel delivery are good. How about ignition? Do you have spark at the plugs? If that checks out, are you getting pulsing signals at the fuel injectors?
Last edited by ClothSeats; Sep 7, 2020 at 10:55 AM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,430
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From: Cape Coral, Florida
This is mainly an ignition circuit DTC...ECM is receiving 2 separate voltages !!...this is what needs to be looked at !!
Last edited by C5 Diag; May 26, 2021 at 07:53 AM.
Thread Starter
7th Gear
Joined: Sep 2020
Posts: 7
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No spark at plugs. Will check injectors next. Thank you.
Heel & Toe
Joined: May 2016
Posts: 22
Likes: 1
P1682
Did you resolve this issue? It looks like i’m having the same exact issue myself, and i’ve tried everything you did. Gonna try swapping for another battery tomorrow. Crank sensor is good. Fuses all check out, fuel pressure is there. No spark though. Havent found any damaged wires. I may have to try a new ecm.
Thread Starter
7th Gear
Joined: Sep 2020
Posts: 7
Likes: 0
Did you resolve this issue? It looks like i’m having the same exact issue myself, and i’ve tried everything you did. Gonna try swapping for another battery tomorrow. Crank sensor is good. Fuses all check out, fuel pressure is there. No spark though. Havent found any damaged wires. I may have to try a new ecm.
Let us know if this ends up being the problem on yours as well.
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Heel & Toe
Joined: May 2016
Posts: 22
Likes: 1
I did finally resolve this issue. My apologies for not posting the solution earlier. I did try a new ECM without success. gapcity, do you have a lead acid battery or AGM? The reason I ask is that my issue was found in the main wiring harness directly under the battery tray. There was massive corrosion throughout numerous wires inside that thick harness. Lots of battery acid under the tray was the first clue. The harness is no longer available so repair of about thirty wires had to be spliced. That sounds like a time consuming task but if you were to locate a new harness, you would need to access all the connection points not only at the ECM but under the dash and throughout the engine bay and beyond.
Let us know if this ends up being the problem on yours as well.
Let us know if this ends up being the problem on yours as well.
For anyone trying to resolve this issue, I’d definitely pull up a diagram of the harness and try to find any sort of breakage, or damage. It seems the most common issue based on my research (after looking over the fuses and crank/ignition sensors) is damage to the harness. Definitely double check all your engine grounds so you dont waste hours searching in other areas. Also check and make sure your car has rpm when cranking using any capable obd2 reader. If the crank sensor does not read you will have this issue too.
Thanks for the quick reply OP.
Last edited by gapcity; May 28, 2021 at 03:57 AM.