2002 Dodge Intrepid is pcm really the problem

BRANDON EPP

MEMBER
2002 DODGE INTREPID
6 CYL
FWD
AUTOMATIC
129,678 MILES

I just bought a good car for 900 dollars, and I am a tech myself just no dodge/chys. Experience.
They certainly a different breed lol. The question I went to hook up the computer scanner and I did get power to scanner but the computer wouldnt communicate with the scanner. But I guess dodge has a key on and key off twice check on the dash.
I could retrieve the codes that way. I got p0700 p0134 p0137 p0138, etc all dealing with the oxygen sensors besides p0700 which a refenence to see what transmission had stored. Need I add this car just had new o2 sensor put in it, and ran fine until it went into closed loop, so im asking is the pcm the problem? The guy bought it from took it to the dealer and thats what they said. But why wont it communicate with the scanner?

1 Reply

CARADIODOC

MECHANIC
33,912 POSTS

Hi epp.

I've run into a lot of aftermarket scanners that don't communicate. Never looked into why. I have Chrysler's DRB2 and DRB3. They do a lot more than any aftermarket unit, and with the plug-in card that lets the DRB3 work back to 1994 models, it will do generic mode too for emissions stuff on any OBD vehicle.

Even Chrysler experts feel the Intrepid is "an odd breed". They put the engine in the wrong way for starters. If it helps, the sensors work almost identically to GM products, but they never needed a MAF sensor to run right. Even the Idle Speed Motor is the same part. Earlier MAP sensors were GM parts too. They gave a lot of trouble in the late '80s. As of 1999, when I left the dealership, they had very little trouble with computers. The only exception was the '96 and newer minivan body computer disaster.

There are four O2 sensors. Someone might have performed some repairs but forgot to erase the diagnostic fault codes. If the problem doesn't act up again, they will erase automatically after about 50 starts. You'll need a scanner that can access the transmission computer to read its codes. Code 700 just means the engine computer knows there's a code in the transmission computer.

If there is really a problem in the transmission or with its sensors, it will stay in second gear. To reset it, you just have to turn the ignition switch off and restart the engine. If it starts out right away in second gear, suspect a problem with a sensor or its reading. If it starts out in first, then defaults back to second gear immediately after an upshift, the computer has detected slippage in one of the clutch packs. With the DRB3, you can read the Clutch Volume Index, (CVI). Those are four fluid volumes for the four clutch packs. I don't remember what normal is, but those numbers will give you an idea of how much clutch wear has taken place.

Caradiodoc