for anyone with TCU problems

[zigg_1311]

For anyone who has the d4 light stay on and had to replace their TCU. This is happening to my 91 ex, wanting to know what tcu should i replace it with. I heard 90-91 lx tcu's are good to replace, and if you have had your d4 light stay and fixed let me know what it took to fix it. Thx to all

[jhondayaaj]

well, pull the code first. and go from there.

[9tAkord]

Is it the D4 light flashing or the S light staying on? Anyway, I had to replace my TCU on my 90 cb because a couple of resistors and capacitors burned out last summer. I had learned about this compatibility issues on our TCU's.
First tried a TCU from a wagon- no S light, tranny shifts but it won't unlock the shift solenoid (shift lock). I have to unlock it maually to shift out of park.
Second tried one from a 92- no S light on park although once on D4 S light comes on, shifts fine, unlock shift lock. I had to get a TCU with the exact same part no. of the broken one and everything is fine. I got a rebuilt one for about $165 off ebay and have my broken one rebuilt by them in exchange of the wagon TCU that I have, Apparently they sell the wagon ones for more. So I have another one as a back-up just in case the other fail although it's been working fine from July so I think it is safe to say that it is OK. I have the back up with part n. 28100-PXO-922-M1 3LX if it's the same and you really sure that you need it, I can sell it to you just send me a PM.

[10thcb7]

I dont know much about the 90-91's "S" light. On 92-93 models we have a D4 light. If you do not know how or havent checked your TCU code the way to find out; (for the 92-93 atleast) Ais by jumping the blue connecter under the glovebox B turning the key to the on posistion C throwing the car into D. DO NOT TURN ON THE CAR. Man I suggest you go to a scrap yard with a hand full of tools 10mm deep socket wire cutters needle nose and 2 screw drivers. Pop open the cases on a 90-91 and check for outside water damage and if any parts of the TCU are burned. DO NO PAY OVER 25bux for this well eh maybe 40.