No tach output
Thread Starter
11 Second Club
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Joined: Mar 2007
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From: Hudsonville, MI
No tach output I have checked the wiring for the cam sensor and tach, no problems there. I had a P0343 cam sensor code, I found that I had a broke wire in my harness, I fixed that, it cleared the code but still do not have a tach.
Any ideas?
Any ideas?
On The Tree
Joined: Apr 2006
Posts: 135
Likes: 2
From: Burlington, Wisconsin
Do You have 12V and ground at the cam sensor plug?
Do you have continuity between the signal return wire at the cam sensor and the PCM????
Just fixed a truck a couple of days ago that had no tach and cam sensor codes, found a lack of 12 volts at the cam sensor!!!
Mike
Do you have continuity between the signal return wire at the cam sensor and the PCM????
Just fixed a truck a couple of days ago that had no tach and cam sensor codes, found a lack of 12 volts at the cam sensor!!!
Mike
Thread Starter
11 Second Club
iTrader: (17)
Joined: Mar 2007
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From: Hudsonville, MI
I just verified 12vdc at the cam sensor 12v reference, good ground on the low reference and continuity through the signal line to the pcm all checked good. Re-checked 12vdc present at tach, good ground, also continuity from PCM C2 pin 10 to tach, no issues. I am stumped, I think I am going to pull the tach out and bring it into work, put it on my waveform generator and see if I can get it to work.
I noticed the shift light only comes on at 0 with the key in run, engine off. When the key is cycled on it goes to the selected shift point but the light does not come on, so i believe it may be the tach itself. I do not remember if the shift light comes on before every start up.
I noticed the shift light only comes on at 0 with the key in run, engine off. When the key is cycled on it goes to the selected shift point but the light does not come on, so i believe it may be the tach itself. I do not remember if the shift light comes on before every start up.
Thread Starter
11 Second Club
iTrader: (17)
Joined: Mar 2007
Posts: 756
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From: Hudsonville, MI
HPtuners reads and displays hi to low signals from the cam sensor so I know the cam sensor is working and the wiring is good. The tach line out of the PCM has no signal, I will be replacing the computer I suppose
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Teching In
Joined: Jan 2010
Posts: 20
Likes: 1
If this is an engine swap or you are using an aftermarket tach and you are using an 03+ pcm you may need to do a pull up resistor. http://www.lt1swap.com/lsx_tach.htm
My tach did not work until I did this circuit, now works like a champ.
My tach did not work until I did this circuit, now works like a champ.
Bringing this one back. I've got P0342 Low Voltage Cam Position Sensor, and no tach. From what I've already learned in this thread, I'll check the wiring for good voltage, but what about the tach!?!?!
