99 Honda Accord ECM/ECU Transmission question
12-22-2014, 12:15 PM
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99 Honda Accord ECM/ECU Transmission question
Hello. I am new here.
I am requesting your help for something technical.
About 3 months ago i had my transmission rebuild by my mechanic. It drove beautiful after that. But about 2 weeks ago I started having issues with the transmission shifting really bad.
The rpms where going high and low by itself when I was driving at the highway. When I was at 40 mph the engine accelerated by itself really and high and then low without me hitting the gas as I had the car in cruise control. Just the rpms would go really high but the car didn't move faster.
Anyhow I manage to take it to my mechanic. He took the whole tranmission apart after checking all of the sensors, switch solenoid, linear and torque solenoids.
I was getting incorrect gear ratio from the scanner.
He said everything look great inside, the torque converter, all of the oring with screen where really clean, he used the honda o.e. fluid. All of the solenoids and sensors where work perfect.
He then said that when the car is cold it runs fine, but after a few minutes, when it warms up it starts having shifting problems again. I tested the car and went for a test drive to confirm it and he was right.
The car jerks in second, third and fourth gear. The rpms go high and low by ityself.
He said the only remaining thing that can be causing this shifting problem is the transmission module unit.
He said on my car it doesn't use a separate tcm. He said the ECM which is located in the middle bottom console is the one that controls also the transmission solenoids and sensors.
The part # is 37820-PAA-L50
My mechanic told me it has to be the same ECM with the exact same number.
I did alot of research on google, called alot of jink yards, and nobody has that ecm part #. I found out that 37820-PAA-407 is the new one that replaces the L50 model but is very expensive, around $700 to $800 dollars from online places that sell honda parts, and the dealer is $1000.
Most of the junk yards have 37820-PAA-L60, L61, L11, A50
Only the last 3 digits change. I want to know if any of those models are compatible with the L50
I saw online that the new one ending in 407 says:
Replaces ' 37820-PAA-A50, 37820-PAA-L50, 37820-PAA-L60, 37820-PAA-L61'
If that is the case, does that mean that if i go to the junk yard and get any of those models it will work for my car?
I read somewhere that the most important number are the ones in the middle which in my case would be PAA
Can someone who has run into this issue help me out. I really hope that the ecm is the problem and i can get any of the above models and it fixes my transmission shifting problem.
Oh yes by the way, if they are interchangeable, does that mean that is just plug and play or does it need programming. My mechanic told me that my key is a regular key, it doesn't have a resistor inside so no programming is needed but then again i think he meant only if I get the exact same part number ecm, so if I get any of the other models, would it need to be program?
Sorry for the long post, I am confused and need my car. Is been in his house for almost 2 weeks. He can't figure out the problem and is assuming the computer is the last thing remaining causing shifting problem.
I am requesting your help for something technical.
About 3 months ago i had my transmission rebuild by my mechanic. It drove beautiful after that. But about 2 weeks ago I started having issues with the transmission shifting really bad.
The rpms where going high and low by itself when I was driving at the highway. When I was at 40 mph the engine accelerated by itself really and high and then low without me hitting the gas as I had the car in cruise control. Just the rpms would go really high but the car didn't move faster.
Anyhow I manage to take it to my mechanic. He took the whole tranmission apart after checking all of the sensors, switch solenoid, linear and torque solenoids.
I was getting incorrect gear ratio from the scanner.
He said everything look great inside, the torque converter, all of the oring with screen where really clean, he used the honda o.e. fluid. All of the solenoids and sensors where work perfect.
He then said that when the car is cold it runs fine, but after a few minutes, when it warms up it starts having shifting problems again. I tested the car and went for a test drive to confirm it and he was right.
The car jerks in second, third and fourth gear. The rpms go high and low by ityself.
He said the only remaining thing that can be causing this shifting problem is the transmission module unit.
He said on my car it doesn't use a separate tcm. He said the ECM which is located in the middle bottom console is the one that controls also the transmission solenoids and sensors.
The part # is 37820-PAA-L50
My mechanic told me it has to be the same ECM with the exact same number.
I did alot of research on google, called alot of jink yards, and nobody has that ecm part #. I found out that 37820-PAA-407 is the new one that replaces the L50 model but is very expensive, around $700 to $800 dollars from online places that sell honda parts, and the dealer is $1000.
Most of the junk yards have 37820-PAA-L60, L61, L11, A50
Only the last 3 digits change. I want to know if any of those models are compatible with the L50
I saw online that the new one ending in 407 says:
Replaces ' 37820-PAA-A50, 37820-PAA-L50, 37820-PAA-L60, 37820-PAA-L61'
If that is the case, does that mean that if i go to the junk yard and get any of those models it will work for my car?
I read somewhere that the most important number are the ones in the middle which in my case would be PAA
Can someone who has run into this issue help me out. I really hope that the ecm is the problem and i can get any of the above models and it fixes my transmission shifting problem.
Oh yes by the way, if they are interchangeable, does that mean that is just plug and play or does it need programming. My mechanic told me that my key is a regular key, it doesn't have a resistor inside so no programming is needed but then again i think he meant only if I get the exact same part number ecm, so if I get any of the other models, would it need to be program?
Sorry for the long post, I am confused and need my car. Is been in his house for almost 2 weeks. He can't figure out the problem and is assuming the computer is the last thing remaining causing shifting problem.
12-31-2014, 09:38 PM
#2
Honda-Tech Member
Re: 99 Honda Accord ECM/ECU Transmission question
Line oil pressure leak is likely. This can be caused by a worn out oil pump housing or another main hydraulic leak, the gears rarely show wear in normal service.
I must first ask why it was rebuilt. What was your original complaint vs the new complaint? An incorrect gear ratio code will only set when the PCM successfully commands a shift solenoid and the result is not correct, which indicates a mechanical failure. (IE torn o-rings, defective rebuild etc.)
I must first ask why it was rebuilt. What was your original complaint vs the new complaint? An incorrect gear ratio code will only set when the PCM successfully commands a shift solenoid and the result is not correct, which indicates a mechanical failure. (IE torn o-rings, defective rebuild etc.)
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