LS3 swap with an engine shutdown P1682 problem
Thread Starter
Registered User
Joined: Mar 2025
Posts: 1
Likes: 0
LS3 swap with an engine shutdown P1682 problem Hey guys, new here!
1955 Bel Air with a GM LS3 crate engine and 6MT, using the LS376/480 Engine Controller Kit, P/N 19354330. I have taken 2 separate 2 hour drives on separate days, 1 day this occurred 6 times, the next 0. No other problems aside from this:
Completely randomly, but more often under load (Even light throttle), engine will out of nowhere shutdown, CEL illuminates. Code P1682. 1 of 3 things will happen next, also completely random:
1) Engine will crank no start without a battery disconnect cycle, then starts/runs normal with CEL.
2) Engine will restart right away normal with CEL.
3) Engine will restart, but idle only, no response from throttle with CEL.
I have bypassed the ignition switch, and I have checked all fuses/relays. Problem prevails.
Any ideas before I trace wires?
1955 Bel Air with a GM LS3 crate engine and 6MT, using the LS376/480 Engine Controller Kit, P/N 19354330. I have taken 2 separate 2 hour drives on separate days, 1 day this occurred 6 times, the next 0. No other problems aside from this:
Completely randomly, but more often under load (Even light throttle), engine will out of nowhere shutdown, CEL illuminates. Code P1682. 1 of 3 things will happen next, also completely random:
1) Engine will crank no start without a battery disconnect cycle, then starts/runs normal with CEL.
2) Engine will restart right away normal with CEL.
3) Engine will restart, but idle only, no response from throttle with CEL.
I have bypassed the ignition switch, and I have checked all fuses/relays. Problem prevails.
Any ideas before I trace wires?
TECH Fanatic
Joined: Jan 2009
Posts: 1,063
Likes: 475
From: Bostwick, GA.
What Does P1682 Code Ignition 1 Switch Circuit 2 Mean?
Being you have a new switch and still have the issue, it's time to do the 100% inspection of all wiring, connectors, grounds, etc.
Being you have a new switch and still have the issue, it's time to do the 100% inspection of all wiring, connectors, grounds, etc.
