91 dash problem - no codes - ecm replaced
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Instructor
Joined: Jul 2002
Posts: 172
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From: jax fl
91 dash problem - no codes - ecm replaced
My 91 l98 has been giving me problems with the lcd dash not working. Bought a used dash cluser off of ebay and installed it shows digits and parts of the fuel gauge while running but not legible.
I have replaced the ECM and no change. When driving it the digits change but are not readable and the range and fuel gauge come and go.
I used a Tech2 (borrowed from my car engineer neighbors work) scan tool and it is showing no codes. However it seemed to lose connection to the ecm a couple of times a minute.
A couple of questions.. Does anyone know where the grounds that might effect this are located? Even using the factory manual I am not sure where the CCM is under the dash? is it behind the radio. Anyone ever replace a CCM?
Any help would be greatly appreciated..
I have replaced the ECM and no change. When driving it the digits change but are not readable and the range and fuel gauge come and go.
I used a Tech2 (borrowed from my car engineer neighbors work) scan tool and it is showing no codes. However it seemed to lose connection to the ecm a couple of times a minute.
A couple of questions.. Does anyone know where the grounds that might effect this are located? Even using the factory manual I am not sure where the CCM is under the dash? is it behind the radio. Anyone ever replace a CCM?
Any help would be greatly appreciated..
Pro
Joined: Apr 2001
Posts: 744
Likes: 13
From: Lenoir City TN
My 91 started doing this and gradually got worse. It turned out that the connections at the CCM needed cleaning. Once I did that the problem was gone.
To get to the CCM you will have to remove the covers under the steering column. Then remove the carpet on the tunnel on the drivers side. The CCM is located behind the radio, but you can't get to it thru there, it has to come out from under the drivers dash area even though it helped me to remove the radio so I could see it. If I remember, there is a cover that the CCM is mounted to that you remove to pull the unit out. It comes out from behind the radio towards the drivers side leg area.
Once I got it out I unplugged all the connectors to it, cleaned them with contact cleaner, reconnected them an the problem was solved. Just take your time, it is very tight in there.
Hopes this helps.
To get to the CCM you will have to remove the covers under the steering column. Then remove the carpet on the tunnel on the drivers side. The CCM is located behind the radio, but you can't get to it thru there, it has to come out from under the drivers dash area even though it helped me to remove the radio so I could see it. If I remember, there is a cover that the CCM is mounted to that you remove to pull the unit out. It comes out from behind the radio towards the drivers side leg area.
Once I got it out I unplugged all the connectors to it, cleaned them with contact cleaner, reconnected them an the problem was solved. Just take your time, it is very tight in there.
Hopes this helps.
Thread Starter
Instructor
Joined: Jul 2002
Posts: 172
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From: jax fl
Thanks for the info guys!
I will try getting to the ccm and see if I can clean the contacts and make sure they are tight. It is nice to hear from some other people who have had the same issue.
Thans for offer to scan the manual but I do have a copy of the factory service manual and what you guys are saying makes sense looking at it again. I will let you know how it turns out
Thans for offer to scan the manual but I do have a copy of the factory service manual and what you guys are saying makes sense looking at it again. I will let you know how it turns out
