D6r MRToo214 I have lost RPM reading on display. No codes at all I can still see gear selection and speed but nothing on rpm. I can see rpm in ECM when plugged it with et. When in PCM engine speed it say enabled parameter. I was wondering if the dash gets its rpm from the ecm or different sensor somwhere.
Do all the gauges (temp, press, etc) do a full sweep plus light up alkl the icons in the rectangular monitor window when the panel does its self test when you first turn the key ON.? The engine RPM is reported to the Engine ECM by the two speed/timing sensors. That data is then transmitted via the Cat Datalink to the Monitor System. If you can see a valid engine RPM signal in ET then it is most likely that something has gone AWOL in the circuitry of the Monitor panel. The only other thing I can suggest is to check the Harness Code Plug located at CONN 66 behind the dash.
Yes everything does the full sweep and all the lights come on and go off
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I check it plug connection is good
It was only a possibility. I think the panel is most likely the problem.
Question: Regarding the rectangular Monitor window. Do ANY of the icons (e.g. SERV CODE) work when you power it up.? Can you get it to show transmission gear, ground speed, or direction of travel.? Can you get it to show Diagnostic Codes.? If there are no Codes it should show three dashes.
Yes it shows gear selection and speed And yes when there are codes present I can see them.
Well all the data is sent to the Monitor Control via the Datalink. You can see an engine RPM signal with ET when you hook up to the Engine ECM. All other signals are reaching the Monitor, so it's unlikely there is a Datalink error, because that should throw up a Code. IMHO it has to be something AWOL in the circuitry of the Monitor Panel. Going to be an expensive fix though. Be aware that if you get a new 252-4501 module then AFAIK they come unprogrammed.
I was just talking to the operator. He told me when the rpm quit reading he also lost his half gears. Idk if they might have any thing to do with one another. I’m going to troubleshoot half gears loss tomorrow.
It's possible but without any Codes to go on it might be somewhat of a challenge.