tach

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Hi there,
My tach hasn't worked for some time now. Has anyone had this problem with theres? I would like to fix it But don't know where to start. It doesn't look like the sending has moved. The manuel said to check PCM connection number 42. Does anyone know where this connector is? Any help would be greatly appreciated. Thank You Jeff

 

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Jeff
The connector is on passenger side firewall behind wheel well. (PCm)
But it is more likely the connection for the engine speed sensor located directly above engine speed sensor toward top of engine. The ground for sensor is on front drivers side intake manifold( or head/block)but doubt it is ground or you would loose other things also. Check wires, connections, grounds,fuses. Check connection to tachometer in dash panel.
If you have auto trans(if nothing is wrong with shifting) or charge(voltemeter) is Ok you mite want to check connections from Pcm to tach first.
Also need to know what year truck. Electrical wiring could have changed between years.

[This message has been edited by Missouri Mule (edited 10-07-2000). ]

 

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Hold down the trip button and hold it down with ignition off. Turn the key to the on position but do not start it. Keep the button down until "check" appears in the odometer lights. Let go of the trip button and the insturment panel will do a self check. It takes a few seconds and the lights will come on then the guages will travel a little at a time until maxed out. Sometimes this will get it working but if not you know it's not the guage. Same goes with all guages.

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1999 QC 5 Speed 4X4 3. 54LS White/Driftwood Agate with Almost every option, 285 BFG's 16X8 custom rims W/ Aboott speedometer fix, 3500 tailgate lights, Amsoil Air Filter, Nerf Bars W/ much more instore.

 

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Both posts are right on. I think that on the 2000/01 the engine speed was calculated by the ECM with the input from the Crankshaft Position Indicator. I'm not sure about that. Seems like I gathered that from something I read in the shop manual. If that's the case, then all that is working. It would be between the ECM and the dash.

 

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bakwudz,
My truck is a 95 with a 5 sp. I tried holding in the trip button. It didn't work with my truck! I tried the 3 second on&off with the ignition. I got a 55 code with that method. That didn't tell me anything. I'll have to check the connection in the front of the engine. Thanks for your help. Jeff

 

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Jeff,holding down the trip button will do nothing on a'95,it only works on the newer model digital odo. Aways best to state your model year,2 or 4 wd and other info to get a good answer. A 55 code is used to end all troble code messages,it tells you the check is finished. If a 55 is all you got,the check found nothing else wrong. I think you have a bad or dirty connection at the engine speed sensor at the front of the engine.

 

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Hi again,

Just looked at the connection at the front of the engine. It was very clean without any dirt in it. When I get time I will check the connection at the PCM for power. Thanks for all your help. I will try to remember to use my trucks yr & transmission info. in the future. Thanks again Jeff