code 42
Melting Slicks
Joined: Nov 2016
Posts: 2,081
Likes: 2,878
From: So Cal
2023 C4 of the Year Finalist - Unmodified
What year, which engine?
On an L98, Code 42 will set when the Set Timing connector is disconnected to use a timing light to check the timing. When the connector is reconnected, the Service Engine Soon light goes off with the next key cycle. The Code 42 remains for 50 Ignition cycles, but doesn't affect the way the engine runs before it self-clears. << This is probably the most likely scenario for a Code 42 on L98s.
A Code 42 on an LT1 is very likely to be the Ignition Control Module. If you have an LT1 that cranks but does not fire, and there is a Code 42 but no Code 16, it is highly likely that the ICM has failed.
The LT5 also has a Code 42.
Need to know the engine, and perhaps some details, like does it run, or did you just happen to find Code 42 in memory in an L98 after the smog tech checked the timing?
On an L98, Code 42 will set when the Set Timing connector is disconnected to use a timing light to check the timing. When the connector is reconnected, the Service Engine Soon light goes off with the next key cycle. The Code 42 remains for 50 Ignition cycles, but doesn't affect the way the engine runs before it self-clears. << This is probably the most likely scenario for a Code 42 on L98s.
A Code 42 on an LT1 is very likely to be the Ignition Control Module. If you have an LT1 that cranks but does not fire, and there is a Code 42 but no Code 16, it is highly likely that the ICM has failed.
The LT5 also has a Code 42.
Need to know the engine, and perhaps some details, like does it run, or did you just happen to find Code 42 in memory in an L98 after the smog tech checked the timing?
Racer
Joined: Mar 2025
Posts: 444
Likes: 213
Advanced
Joined: Jan 2015
Posts: 62
Likes: 4
From: Surf City USA
What year, which engine?
On an L98, Code 42 will set when the Set Timing connector is disconnected to use a timing light to check the timing. When the connector is reconnected, the Service Engine Soon light goes off with the next key cycle. The Code 42 remains for 50 Ignition cycles, but doesn't affect the way the engine runs before it self-clears. << This is probably the most likely scenario for a Code 42 on L98s.
A Code 42 on an LT1 is very likely to be the Ignition Control Module. If you have an LT1 that cranks but does not fire, and there is a Code 42 but no Code 16, it is highly likely that the ICM has failed.
The LT5 also has a Code 42.
Need to know the engine, and perhaps some details, like does it run, or did you just happen to find Code 42 in memory in an L98 after the smog tech checked the timing?
On an L98, Code 42 will set when the Set Timing connector is disconnected to use a timing light to check the timing. When the connector is reconnected, the Service Engine Soon light goes off with the next key cycle. The Code 42 remains for 50 Ignition cycles, but doesn't affect the way the engine runs before it self-clears. << This is probably the most likely scenario for a Code 42 on L98s.
A Code 42 on an LT1 is very likely to be the Ignition Control Module. If you have an LT1 that cranks but does not fire, and there is a Code 42 but no Code 16, it is highly likely that the ICM has failed.
The LT5 also has a Code 42.
Need to know the engine, and perhaps some details, like does it run, or did you just happen to find Code 42 in memory in an L98 after the smog tech checked the timing?
Thanks for the reply.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
7 Bolt-On Upgrades From Extreme Online Store to Level Up Your C6 Corvette
Pouria Savadkouei
How Likely Are These Five 2027 Corvette Rumors to Be True?
Brett Foote
9 Best Corvettes You Can Buy for Half Price (& 1 You Should NEVER Buy!)
Joe Kucinski
8 Very Best Corvettes of Amelia Island 2026
Joe Kucinski
Top 10 WORST Corvette Engineering Failures of All Time!
Joe Kucinski
10 Records the C8 Corvette Generation Has SMASHED (& 1 Glaring Failure)
Joe Kucinski
7 Wildest Corvette Concepts Ever Made
Brett Foote
Advanced
Joined: Jan 2015
Posts: 62
Likes: 4
From: Surf City USA
