LT4 Service Light Issue
Thread Starter
2nd Gear
Joined: Oct 2013
Posts: 2
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LT4 Service Light Issue
So I have encountered an issue pertaining to service lights on my 1996 LT4. The car was driven to my house about a year ago and everything was fine. No service lights were on according to a relative who delivered the car to my place. I also recall not noticing any service lights either. In my driveway though after a wash or two, the Optispark went out and so did most of the wiring to the engine. Both were replaced and now when the car turns on every single service light comes on. Is it common for this to happen? Or by chance since most of the electrical was shorted out it caused the sensors to freak out?
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
You need to pull the codes. The SES light requires a scanner or code reader since a '96 is OBD-2. The remaining codes for the CCM, Traction Control, Ride Control (if equipped), etc can be accessed via the Instrument Panel and buttons to the right of the cluster.
If you hosed down the engine, especially if you used a pressure washer, then yes there is a possibility that the wiring connectors are corroded. Could also be as simple as a loose or corroded series of ground wires.
Having said all of the above, I have never seen "every single" light come on due to washing. That would be ABS, Traction Control, Service Engine Soon, Security, flashing "SYS" on the IP, Ride Control and LTPWS (if equipped with both), brake warning, etc. Perhaps a pic of said lights and a list of codes?
With zero diagnostics, it's pretty darn hard to trouble-shoot other than saying "it's broke".
If you hosed down the engine, especially if you used a pressure washer, then yes there is a possibility that the wiring connectors are corroded. Could also be as simple as a loose or corroded series of ground wires.
Having said all of the above, I have never seen "every single" light come on due to washing. That would be ABS, Traction Control, Service Engine Soon, Security, flashing "SYS" on the IP, Ride Control and LTPWS (if equipped with both), brake warning, etc. Perhaps a pic of said lights and a list of codes?
With zero diagnostics, it's pretty darn hard to trouble-shoot other than saying "it's broke".
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
So, does the car run?
If so, does it run well, or poorly?
What all, exactly, was replaced after the washing incidient (hopefully you learned from this)?
Agreed that you need to get a scanner and run the codes. This will help you figure out which connections you specifically need to look at.
If so, does it run well, or poorly?
What all, exactly, was replaced after the washing incidient (hopefully you learned from this)?
Agreed that you need to get a scanner and run the codes. This will help you figure out which connections you specifically need to look at.
