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97 Montana problem

We have a 97 Montana with 102K miles on it and it had been reliable. Today, after stopping to make a turn it felt like it stalled. I turned off the A/C and hit the gas it wasn't stalled but the RPM needle dropped as if the engine wasn't running. Then it went back up. Then the "Service Engine Soon" light came on. Stopped by AutoZone to have them check the codes but the guy said that he wasn't able to read from the computer. I'm not sure he really wanted to do it. But, he claimed that he can't get a reading and something was wrong with the wiring to the computer. Does that make sense?

Then on the way back home the RPM needle dropped and stayed there. The Van appears to be running fine.

Anyone kind enough to help pointing me in the right direction would be appreciated.

Reply to
eihab
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Rey

Reply to
Reynaud

Rey, Would you happen to know which sensor is responsible for sending the RPM signal? Thanks

Reply to
eihab

I think that one of the engine's two crankshaft sensors is the origin of the tach signal. Those digital signals go to the ignition control module and from there to the powertrain control module. The PCM sends a digital signal to the instrument cluster where the electronics convert it to the analog tach indication.

Reply to
Silver Surfer

Thank you so much for your help. This is status update;

First the DLC (data link connector) fuse was blown. Replacing that gave me access to the computer and retreived a P0336 code. Looking it up; "Crankshaft Position Sensor Circuit, range or performance problem"

Well, we have 2 CPS in the 3.4L engine, one is a 7X and the other a 24X and neither are easy to get to. So, the testing before replacing was out. I replaced both and all is well!

Thanks again for all the help!

Reply to
eihabe

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