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When I turn my ignition to RUN, my speedometer needle “proves out” (sweeps across dial and back). I then get a reading on my odometer – E 08 6. I have read that this stands for “E” = English (mph); 08 = microprocessor revision; and 6 = number of conversion constant changes remaining.
With this now known, it is obvious that module is entering calibration mode as soon as the ignition is turned to the RUN position.
Questions are:
1. Why is it going into calibration mode without utilizing the dealer mode programming by enabling the single-terminal connector (Circuit #567)?
2. If I simply go through the calibration steps, will the speedometer/odometer function correctly when done? Or, will it just simply reduce the number of conversion constants remaining and enter calibration mode the next time I start the vehicle again?
3. Could this have anything thing to do with VSS/ABS in the rearend or the PMOS going bad?
4. Am I completely off base????
To get it to prove out and show that information (E 08 6) you're supposed to hold the RESET button while turning the key to RUN. Check and see if that button is sticking.
The button is not sticking, but now that you mention that, when I push the reset button it scrambles the odometer readout and remains that way until I turn off the ignition and turn it back on again.
Pushing SELECT will change the odometer to all zeros, ones, twos, etc. Is that what yours is doing? Pressing RESET should change the screen to the conversion constant followed by CAL.
This is for after you've turned on the key with RESET pressed.
Brown 4x4 - you are correct. I must have pushed the SELECT. Do you have any answers to questions 1 & 2 of the original post? You seem to have recalibrated ones before or have been at least down this road once before.
Wow, sorry about that...I was reading too fast and missed your questions. The PSOM will go into calibration mode to allow you to see how many times you have left, what conversion constant it's set at, and to check operation of all odometer digits (pressing SELECT). It won't actually allow you to change the constant without grounding the connector under the glove box. Are you wanting to recalibrate it for your 32" tires? Let me know if you need the procedure and constant.
I did not WANT to calibrate it. I started my truck one morning and the speedometer proved out and the E 08 6 reading appeared on my odometer. It has been this way for weeks now. I will recalibrate it if need be. I just want to know why it happened by itself and if I recalibrate it, will it solve this problem?
I have the procedure and the constant needed. I just don’t want to recalibrate it and it not work, but then take my calibration allowances to 5 then 4 and so one. Once I record 6, it is then time for a new PMOS, correct?
Once I record 6, it is then time for a new PMOS, correct?
Correct, or you can stay stuck forever with whatever you programmed it last.
Sounds to me like the RESET button is stuck or there's a short somewhere in the PSOM. If that's the case, you'll probably need a new PSOM. I guess you could try taking the cluster apart to see if you find anything. You'll see how the black button presses a smaller button soldered on the circuit board. Maybe it's stuck.
Okay, that is a good starting point. I had the cluster out today, but over looked checking the reset button. Thanks for the help. If you think of anything else to check, please post it. I’m up for all suggestions. Thanks again for your posts!