LS1LT1 Forum banner

throwing 8 codes on a 94 z28

2764 Views 10 Replies 2 Participants Last post by  chuck nasty
the 8 codes it is throwing are:


42:electronic spark timing circuit open or shorted

43: electronic spark control circuit low voltage

44: lean exhaust left side

45: rich exhaust left side

51: computer faulty

53: system voltage too high over 17.7

54: fuel pump circuit fault

55: electronic control module fault or oxygen sensor fault




ok so here is what it does. when you start it up as it warms up the coolant fans goto 12 volt mode voltage goes up to like 15 or 16, car sounds like timing is screwed up. when driving around if under 1/4 throttle no light sounds good runs good, over 1/4 throttle bad timing sound, check engine light, voltage increase, fans on 12 volt circuit, poor acceleration.


right now i am leaning towards the ecu is screwed up. but i would like to hear other opinions as well. i have already disconnected the battery and hooke dit back up after 15 minutes. i already have cleaned out all the sensor connections except the ecu one (doing that in a bit), changed 7 plugs (damn front one on passenger side is a pain waiting till it warms up to work on it).
See less See more
1 - 11 of 11 Posts
What are you scanning this with? 54 is not even a valid code. I don't understand what "fans go to 12v mode" or "sounds like timing is screwed up" means. Fans come on with trouble codes, so you might mean that.

Have you monitored the system voltage with a meter? If it is actually getting an over voltage condition (likely a problems with the regulator in the alternator), it could cause all kinds of odd things. I would rectify that first.

Click the link in my sig for a valid list of trouble codes for the 4th gen LT1 f-body.
i used an innova obd 1 scanner. i read that the fans ahve a 6 volt and 12 volt mode. 6 volt mode is low speed 12 volt being high speed. fans go into high speed when the light comes on. by sounds like timing is messed up i mean misfires, no i have no codes for knock. no i have not yet checked the system with a meter yet, too cold right now i am just going off the volt gauge on the dash
The fans run in series or parallel for speed control. When they come on with DTCs, it is always high speed. Are you the same guy on the other board with the L99 swap? Fix the over voltage issue.

I have seen more complaints about people trying to use Innova scanners for some reason. They either don't work or don't work right at times.
nope no swap i just bought this car. ill look into the over vooltage issue. so you are saying the scanner is feeding me incorrect codes? that sucks
nope no swap i just bought this car. ill look into the over vooltage issue. so you are saying the scanner is feeding me incorrect codes? that sucks
Just saying I have read of issues with Innova scanners. I obviously can't tell you if it is right or wrong.

Must be coincidence that two different people post possible over voltage problems with multiple codes on the same day. ;)
ok. so you think the over voltage might be caused by the alternator?
ok. so you think the over voltage might be caused by the alternator?
I think I already said that. :) There isn't anything in the electrical system that can increase voltage. Have it tested.
i noticed on rock auto they have a part listed as voltage regulator. where is this part located as it may also very well be the cause of my problems.
i noticed on rock auto they have a part listed as voltage regulator. where is this part located as it may also very well be the cause of my problems.
The voltage regulator is internal to the alternator. That does not mean it cannot be replaced, if needed. You still need to have it tested to confirm what the problem is.
ok wanted you to confirm that. when i get some time and its not so cold ill get it tested. not really a priority right now
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top