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Hello everyone

I have 02 civic EX Sedan Automatic. Recently I had my transmission rebuilt, they put new sensors and solenoids. Now when I put it in reverse, it has not power. Forward is fine but reverse has no power. The Mechanic told me that I need new ECU. He sais that ECU is not working the way it should.

My questions are

1. Do I need new ECU.
2. Can the current ECU be reprogrammed.
3. Will the new ECU be programed already or will I have to reprograme it.
4. with the installation of new solenoids, do we normally need to reprogram the ECU.

I have already spent over$2500 on this car and its still not working. Honda dealership is asking another $1200 to diagnose the car, get new ECU and programme it. Any help you can provide will be appreciated.

 
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Unless the ECU is throwing a code, I would look at vacuum lines and fluid levels before getting gouged any further or get an opinion from other real mechanic not a forum. The rebuild could have been bad. The ECU comes tuned. If you had one to try real quick, that would be nice! See about getting a ECU/brain from a junkyard if you really think that is what it is. One of the actuators could be off on that transmission. Automatics are known to be a lot of trouble for this gen! Best of luck.

 
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The car has 175K miles on it. It has a check engine light on. I took it to Autozone and the codes are

P1768 = Clutch pressure solenoid "A" Circuit Malfunction
P1773 = Clutch Pressure Solenoid "B" Circuit Malfunction

These both brand new Honda Solenoids that I had installed. Again Forward has no problem at all. It shifts all 4 gears fine. But no power in reverse.

 
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Swap solenoid A and B or the wires first. Cheapest fix!

 
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Connecters for these solenoids have shape which only clicks to each other. I tried to swap the connections but they don't connect.

 
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That is handy. What about swapping entire solenoids? Are they shaped the same in the hole? I just got done looking at a rebuild Auto for 7th gen and man... lots of similar diameters holes for solenoids.

 
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Nope, They can't be swapped. They are two different solenoids with two different shapes.

 
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Just take it back to whoever rebuilt the tranny and make them fix it........? You payed for a functional transmission. Dont put up with their bs.

 
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Yeah tranny shops are notorious for not wanting to fix their mistakes, you gotta haggle them.

 
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1200$ to diagnose the problem???? I think they just want you to go away... or cover their labour to drop and open the tranny....cause i think their tranny rebuild may be bad.

tell you what!... gimme 1200$ and i'll fly down to wherever you live. Rent myself a car to get to yours and diagnose the problem (repair if electrical on the spot) and fly back with money leftover.

In all reality I can't see it taking more than a few hoursfor diagnosis.

even less if you have a friend with a 2001-2005 civic and you unplug the selenoids on his car to see if it runs like yours.


HERE WE GO :

Even new parts fail... so don't skip steps. ECM can not be checked without special equipment so we check all around it.

This transmission is far from being too electrical control dependent.... so i have my doubts as to it being an electrical problem....but....need to follow diag...

Unplug selenoid A, check resistance across pins of selenoid... should be around 5 ohms. Do the same for selenoid B. If resistance is way off - replace selenoid assy
..... If resistance ok.... they should be good....but selenoid could be blocked up...
****cleanlyness is essential....so wash around selenoid before proceeding)
remove selenoid from transmission to inspect (~half litre trans fluid will leak out).. check for any metalic debris in little hole passages. You can apply 12v to the selenoids on the bench and see if they click.(while doing this I blow compressed air to see if they flow/no flow .... then there is no doubt). check each one individually....polarity off the vehicle is irrelevent.
If there was any metal debris----drain fluid from transmission and if more...replace transmission.

if all check ok....
get the wiring diagram for ecm pinout, selenoid pinout. (if you ask polite I may provide)

******unplug neg of vehicle battery, \
unplug ecm from connector- find the proper terminal in the harness side connector. I know you won't have the proper tester tips so (DO NOT JAM A LARGE PIN IN THERE!) use a fine pin or thin paper clip for contact (has to be same or smaller than the terminal pins of the ecm)

check continuity of wires (all 4) from selenoid connector to ecm connector. There is a chance that a wire broke,
If continuity ok then wires ok. plug your selenoids in and check circuit resistance from ecm connector---should be same as selenoids ~5ohms each......

While there (at ecm) check integrity of all grounds and possitive feeds to ECM (you may need to plug back battery without ecm to check positive feeds.

disconnect battery, plug back ecm and replug battery.

Check line pressure of transmission! and clutch pressure.....I personally think something probably messed up in the rebuild.....but without proof we won't assume.

Something somewhere will have failed ! and the dealer or tranny shop should diagnose in this way!


I personally would have jumped straight to line pressure....cause it's the quickest/easiest ---1/2hr, followed by resistance etc..




sounds too complicated?? really isn't. You can start throwing money at the problem by replacing parts without checking, till you find the problem...but gets expensive fast.

 
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Thank you all guys. I took the decision to take it to Honda and get diagnosed. They did a complete diagnose on it and it turned out that this is NOT an electronic issue. I DO NOT need a new ECU. The solenoides are also fine.

The problem was that the transmission shop messed it up. There is a very small washer that goes in the transmission which holds the pressure. If misplaced even a little bit it does not hold the pressure, hence no power in reverse.

There is a special tool put all the washers and gears on the transmission shaft. Honda uses that tool to carefully calibrate and confiture all the washers and gears in place.

Small shops do not have it and they simply put everything together the way they took it out, which causes that washer to move from is pace or placed upside down because of which pressure does not hold in the transmission.

I have taken it back to the transmission shop and even gave them the page with diagram of transmission pieces the way they should come together. Hopefully when they return it on Friday, my civic will move forward AND backward fine.

Its been 3 months of constant searching and going places. All this time I have been driving my sisters brand new Versa, but believe me its no where close to how my civic feels. I miss my civic.

Thanks again.

 
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There is a very small washer that goes in the transmission which holds the pressure. If misplaced even a little bit it does not hold the pressure, hence no power in reverse.

Kashi I have a very similar problem & i remember when i changed transfluid i am supposed to put in a new washer? i havent. Is it the same washer you are talking abt? I cannot move at all my shifter from drive to reverse or neutral?