Lazy PCM, Capacitor replacement how-to?

Steve Bohnen · 12-31-2007, 10:49 AM

Our 93 GC 4L Auto has been great for several years but recently has shown signs of a 'lazy PCM' with the CHECK ENGINE Light syndrome as noted by many other owners (truck only starts if the light comes on, otherwise she just cranks endlessly). I have to get this fixed ASAP since the Jeep is my wife's daily driver. Its PCM has the big finned aluminum heatsink sticking up through the potting gel and only 2 capacitors showing. Has anyone had success with replacing the caps on this type of PCM or should I be going to a wrecker to get a replacement? Cheers and the best of the New Year to all...

Steve B

Briandl · 12-31-2007, 11:58 AM

Seems a lot easier just to get a PCM from a junk yard, they aren't expensive...

greasefingers · 12-31-2007, 12:02 PM

Here is the Link you need
http://www.jeepforum.com/forum/f13/bad-ecu-pcm-help-330109/index2.html

Steve Bohnen · 12-31-2007, 12:05 PM

Thanks guys, I found one at our local Jeep wrecker for $150, got to drive out there and try it out right away. Seems like a good price and it is the right one though it seems this is the original model so wonder if it is going to be good, I guess the manufacture date will be on it like mine is, the one we are replacing was made in March 93...

Cheers

Steve

greasefingers · 12-31-2007, 12:11 PM

The pic below is the capacitors that I bought. I have not done this but I thought I would have them available if I needed them. You need three at $ 1.29/ea they are rated at 35 volts so they are better than the original ones

Briandl · 12-31-2007, 01:05 PM

150.00 is way too much...

Steve Bohnen · 01-01-2008, 11:27 AM

Hi everyone and thanks, unfortunately I had to park the Jeep since it suddenly became totally unreliable re: starting, and absolutley had to get my wife into a car quick so picked up a little 1994 VW Golf for cheap, actually in great shape...anyway, I think I will solder in new caps and see, I think for up here in the Great White North a hundred and a half may be high but the dealer price sure can't be an option..

so the caps sound like the best bet to me...also I have a very electronically inclined 35 year old son who loves to solder and who loves a challenge....

Anyway, will post the results - Cheers and Happy New Year to all..

S

12-31-2007, 11:58 AM	#2
Briandl Registered User Join Date: Mar 2005 Posts: 982 Profile Gallery Classifieds My Jeeps	Seems a lot easier just to get a PCM from a junk yard, they aren't expensive... __________________ 2002 Jeep Grand Cherokee Limited 4.7L H.O. V8

12-31-2007, 01:05 PM	#6
Briandl Registered User Join Date: Mar 2005 Posts: 982 Profile Gallery Classifieds My Jeeps	150.00 is way too much... __________________ 2002 Jeep Grand Cherokee Limited 4.7L H.O. V8

01-01-2008, 11:27 AM	#7
Steve Bohnen Registered User Join Date: Dec 2007 Location: Vancouver British Columbia Posts: 3 Profile Gallery Classifieds My Jeeps	Thanks friends and HNY to all... Hi everyone and thanks, unfortunately I had to park the Jeep since it suddenly became totally unreliable re: starting, and absolutley had to get my wife into a car quick so picked up a little 1994 VW Golf for cheap, actually in great shape...anyway, I think I will solder in new caps and see, I think for up here in the Great White North a hundred and a half may be high but the dealer price sure can't be an option.. so the caps sound like the best bet to me...also I have a very electronically inclined 35 year old son who loves to solder and who loves a challenge.... Anyway, will post the results - Cheers and Happy New Year to all.. S

12-31-2007, 12:05 PM	#4
Steve Bohnen Registered User Join Date: Dec 2007 Location: Vancouver British Columbia Posts: 3 Profile Gallery Classifieds My Jeeps	Thanks guys, I found one at our local Jeep wrecker for $150, got to drive out there and try it out right away. Seems like a good price and it is the right one though it seems this is the original model so wonder if it is going to be good, I guess the manufacture date will be on it like mine is, the one we are replacing was made in March 93... Cheers Steve