Check Engine Light!
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Joined: Sep 2004
Posts: 4,053
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From: Tijeras, New Mexico, 7,000ft up
Check Engine Light!
The Check Engine Light came on today, and stayed on. The Water light has been on for a year. Everything else seems to be working (air, cruise, etc.) so I don't think it is the CPS. I have no idea why a diesel would have a check engine light anyway!
Any ideas????
Mark
Any ideas????
Mark
If the light is red, you might want to check your oil. I'm not sure of the inputs that turn that light on, but you probably have a sensor wire that fell off or broke. You could also try plugging in a scan tool to read the code to identify the source. I think auto zone does it for free.
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Joined: Sep 2004
Posts: 4,053
Likes: 135
From: Tijeras, New Mexico, 7,000ft up
Could my factory oil pressure gauge be lying to me? It seems to be working as normal. Oil level is fine. It comed on when I hit the highway going home.
Is there a scan tool that will work on a 1st gen?
Is there a scan tool that will work on a 1st gen?
Geno's Garage. They sell them for 24 valve trucks, but they are the same size as ours.
http://198.104.149.53/CoastalData/sh...ID=593&CATID=1
Get one solid and one tapped. You can use the tapped one for fuel pressure or just put a pipe plug in it so you don't lose the bleed. I've got a 1.5" 15 psi glycerin filled gauge threaded into mine since I had it laying around. It bounces from 3 to 7 psi at hot idle, revved up it gives a steady 6 psi.
http://198.104.149.53/CoastalData/sh...ID=593&CATID=1
Get one solid and one tapped. You can use the tapped one for fuel pressure or just put a pipe plug in it so you don't lose the bleed. I've got a 1.5" 15 psi glycerin filled gauge threaded into mine since I had it laying around. It bounces from 3 to 7 psi at hot idle, revved up it gives a steady 6 psi.
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Joined: Sep 2004
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From: Tijeras, New Mexico, 7,000ft up
My computer is throwing a code 24, which is TPS voltage high or low. That's wierd because I have a standard that does not have a tps (that I know of).
Is my PCM getting Alzheimers?
Is my PCM getting Alzheimers?
No, I was just trying to find a difference between my PCM and yours. Mine hasn't set code 24. I don't understand why yours would start throwing a code for a sensor it shouldn't even be looking for. Is that the only code?
Thread Starter
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Joined: Sep 2004
Posts: 4,053
Likes: 135
From: Tijeras, New Mexico, 7,000ft up
More on the mystery. I notices the voltage needle riding low when the "check engine" light is on. Also, the cruise control is very weak when the light is on, and lets go frequently. Interestingly, the air stays on, so it's probably not the crank position sensor.
I'm thinking low voltage to the PCM, but I can't figure out why. Id doesn't happen all the time, or it would run the battery down.
I'm at a loss.
Oh, and there seems to be more interference in the radio than before, and it increases with engine speed. I think someone stole my Cummins and stuck in a pinging gasser!
I'm thinking low voltage to the PCM, but I can't figure out why. Id doesn't happen all the time, or it would run the battery down.
I'm at a loss.
Oh, and there seems to be more interference in the radio than before, and it increases with engine speed. I think someone stole my Cummins and stuck in a pinging gasser!


