98 Ram PCM Problem??
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98 Ram PCM Problem??
Hello all,
This is my first post and hope this is in the right place.
I have a 98 Ram 1500 4x4 5.9 vin Z. She got a new engine and rebuilt trans 15K miles ago with all new sensors etc.
Recently I started noticing that the trans would thump....as if torque conv lock up was unlatching/relatching under load at about 40-50 mph, At 60-70 mph seemed ok. My quick fix was to turn OD off under 60 mph and seemed ok. It's gotten worse now...where the thumping has increased...at any speed over 40 with or without OD engaged. With foot off the gas lock-up disengages and no issues.....as soon as I press on the gas, thumping/banging.
Another clue is that when the truck is cold it all works perfectly....then starts acting up after a few minutes of running and up to operating temp. The warmer it gets, the worse it gets to now its almost crazy to drove over 40 mph with the banging.
The latest symptom is after the same warm up period, the engine is starting to miss and even hear a few pops under load. Again when it's cold, all works as it should.
I replaced the throttle position sensor and no change. The post cat O2 sensor is new, the pre-cat sensor is orignal with 195K. Could this be a faulty PCM?,,,or even two unrelated issues. I'm thinking when the O2 sensor goes to closed loop maybe...but would that cause a trans lockup issue?
I checked PCM ground and harnesses for chaffing etc, and all look good.
The computer is not throwing any codes at this point. Any ideas? Thanks!
This is my first post and hope this is in the right place.
I have a 98 Ram 1500 4x4 5.9 vin Z. She got a new engine and rebuilt trans 15K miles ago with all new sensors etc.
Recently I started noticing that the trans would thump....as if torque conv lock up was unlatching/relatching under load at about 40-50 mph, At 60-70 mph seemed ok. My quick fix was to turn OD off under 60 mph and seemed ok. It's gotten worse now...where the thumping has increased...at any speed over 40 with or without OD engaged. With foot off the gas lock-up disengages and no issues.....as soon as I press on the gas, thumping/banging.
Another clue is that when the truck is cold it all works perfectly....then starts acting up after a few minutes of running and up to operating temp. The warmer it gets, the worse it gets to now its almost crazy to drove over 40 mph with the banging.
The latest symptom is after the same warm up period, the engine is starting to miss and even hear a few pops under load. Again when it's cold, all works as it should.
I replaced the throttle position sensor and no change. The post cat O2 sensor is new, the pre-cat sensor is orignal with 195K. Could this be a faulty PCM?,,,or even two unrelated issues. I'm thinking when the O2 sensor goes to closed loop maybe...but would that cause a trans lockup issue?
I checked PCM ground and harnesses for chaffing etc, and all look good.
The computer is not throwing any codes at this point. Any ideas? Thanks!
Retired Moderator - RIP
Joined: May 2008
Posts: 18,729
Likes: 17
From: NH
Nooooo , please don't do that.
I see it's already been moved,deleted, merged or whatever and put in the correct section. 
