PCM/ECM no communication - Dodge Cummins Diesel Forum
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post #1 of 7 (permalink) Old 05-06-2011, 08:55 AM Thread Starter
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PCM/ECM no communication

Hey guys, I've never been registered here but I have used this site on numerous occasions with my truck.

The Problem:
I have a 96 2500 auto. When I'm driving my tranny will switch into 3rd gear and stay in 3rd until i restart my engine. Once I restart my engine I'll have all gears for about 2mins or until I slow back down to 3rd from overdrive.
I took it in to my buddies shop and he hooked up his snapon diagnostic tool and it cant communicate with the computer. My Tranny guys says its something electrical and I'm curious whether to replace the PCM or ECM or whether they are the same. Thanks for your help.

The Truck is for sale also.
96 cummins auto with only 90,000 with rebuilt tranny 15000 on it

Last edited by Twitchy; 05-06-2011 at 08:57 AM.
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post #2 of 7 (permalink) Old 05-06-2011, 09:14 AM
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You only have a PCM, ECMs didn't arrive until the '98 24valves. The most likely culprit, from my limited knowledge of slush boxes, is the throttle position sensor.

97 3500, 2 WD, G56, slightly bombed, 1.2 million miles. Started the second million on 8/24/13
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post #3 of 7 (permalink) Old 05-06-2011, 10:01 AM Thread Starter
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What's weird is I've hooked it up to two different scanners and they don't even communicate with the computer. Anyone know what causes that?
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post #4 of 7 (permalink) Old 05-06-2011, 07:26 PM
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It's because '96 and older have Chrysler's DRB programing.
'97 and newer have OBD programing which most scanners come with.
DRB software is very pricey.

You can also check your codes like this> Diesel Ram DTC's

'95 2500 4wd auto
'95 3500 5 speed heavy hauler
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post #5 of 7 (permalink) Old 05-09-2011, 06:58 AM
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I have a 98 that's doing the same thing with the scanner. Did y'all ever figure this out?

1998 2500 Ext Cab 12 valve Auto 4x4, 15.75*, Pensacola Stage 1s, 4" Turbo Back Exhaust, K&N Replacement Filter, Di Pricol Gauges, #10 Plate 1/2 back, Goerends Tranny w/ Triple Disk TC & new VB, w/ VBA
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post #6 of 7 (permalink) Old 05-09-2011, 12:43 PM
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96 is OBDII

98 2500,4x4auto,48re vb,billet single,shift kit+, Killer B, 4" ss,#10 ff,4gsk,.024s, 5x.014, BHAF,16* gauges,WVO, B164 bypass 2004.5 3500, SRW, FASS WVO, B164 bypass, Edge@1 Sold 96 2500 eclb 3gsk
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post #7 of 7 (permalink) Old 05-18-2011, 04:18 PM Thread Starter
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Its OBDII, for some reason the Scanner(Snap-on) wasn't picking up my truck. I took it back and now it does self recognize my Dodge. My mechanic said he had no idea why it worked now and not earlier.
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