Engine speed sensor and PCM ?

Howling

Howling

Soot Sniffer
So my 1996 has been sitting for a year and a half due to a bad trans. Getting ready to put a new one in so I threw the battery charger on and fired up the truck, noticed I had no tach . Purchased a new Cummins ESS and gapped it to specs. Still no tach.

Checked for 5V at plug had less than 1 volt was like .638 I believe

Ohmed out the grey with black tracer PCM A8 checked out ok

Ohmed out Violent with white tracer 5V supply PCM A17 checked out ok .

Checked the PCM at the A17 pin and I do not have 5V there .

Is there another place to check to see if the pcm is bad ?


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I believe that year should have had 8v at the plug, not 5v. Either way that doesn't help if you have 0.638v. LOL
 
Check the connection at the front of the motor, right in front of the head. Mine was lose and would cause a loss of tach signal.
 
Phooker said:
Check the connection at the front of the motor, right in front of the head. Mine was lose and would cause a loss of tach signal.
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At the plug for the ESS . I put a zip tie around the two ends to keep it tight after I used electrical cleaner and a little dielectric grease.

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Nope , going to check all grounds and see if the pcm is actually getting power .

Dont want to drop 500 on a pcm yet

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I checked fuse 3&8 in the PDC they are good . Checked fuse 9 in the fuse box it was good and had power .

I DO NOT get a wait to start light , check engine or WIF when I go to start.

Going to do some more digging
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You can also take a scanner and see if you get communications, but I am saying the no wait to start is either bad PCM or not powered up.
 
I agree on both .

I plugged in my obd bluetooth that i use and nothing.

Going to check power and ground first.

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zstroken said:
You can also take a scanner and see if you get communications, but I am saying the no wait to start is either bad PCM or not powered up.
Click to expand...
Daniel

Do you happen to have a pinout diagram for a 96 at the PCM

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So I checked the first plug on the pcm (black plug) used a test light and had power at A22 with key off and power at A2 with key on . Put alligator clip on positive terminal and stuck probe in at A31 and 32 and it lite up indicating a good ground.

Looks like its the pcm . Now how do you cipher between a 95 and 96 pcm.

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96-97 is interchangeable.
Check around on Car-Part.com, sometimes you'll get lucky and the "refurbishers" (FS1, ACE, etc.) will have missed one on there.

Mark.
 
If Alldata is correct, the ‘95 PCM has one connector. The ‘96 has three.

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zstroken said:
So how much is the cummins one?
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To repair? They said 128 but also said they will call after diagnosing and let me know cost . Skeptical

Not sure I want to gamble on a 500 used one. Or do I just buy a refurbished one of ebay ??

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