Ecm/tcm??
#1
11-14-2012, 03:04 PM
Ecm/tcm??
I am new to this forum. so please forgive my ignorance when it comes to technical issues.
I'm trying to to repair my son's 2000 Civic from an upper front end collision. I've removed and replaced the radiator support (not fun), hood, upper O2 sensor, and am putting everything back together. As I drove it into my garage, the D3/D4 transmission light kept flashing back and forth. Reverse and Low seemed to work fine, but there's hardy any power in D3/D4. In doing online research, I'm seeing info on ECM's, TCM's, and sensors everywhere. The radiator and AC condenser seem to be undamaged.
Can anyone give me an opinion on why it bounces back and forth between D3 and D4?
Thanks in advance for any help.
I'm trying to to repair my son's 2000 Civic from an upper front end collision. I've removed and replaced the radiator support (not fun), hood, upper O2 sensor, and am putting everything back together. As I drove it into my garage, the D3/D4 transmission light kept flashing back and forth. Reverse and Low seemed to work fine, but there's hardy any power in D3/D4. In doing online research, I'm seeing info on ECM's, TCM's, and sensors everywhere. The radiator and AC condenser seem to be undamaged.
Can anyone give me an opinion on why it bounces back and forth between D3 and D4?
Thanks in advance for any help.
#2
11-15-2012, 11:07 AM
Welcome in,Behind the right hand corner of the dash on the passenger's side (just below the glove compartment) you will find 2 connectors taped to the wire harness with blue tape ( unless someone previously removed the tape). One is a three wire connector (data link connector) the other is a two wire connector. By jumping the two wires on this connector, you check for engine and transmission codes.
With the ignition switch off, connect the two wires together. Have a pen and paper handy. Turn the ignition switch on. The S light (or D4 light if your car doesn't have the S light) should start to flash a code. Might be a combination of long and short flashes. A long flash stands for 10, and short flashes are 1. For example, if the light blinks: long-short-short-short, then that is a code 13. When you find out what code it is, post it and I can tell you what is going on. BTW, 90-93 Accords have a bad habit of burning out the trans computers. So sometimes you won't get a code. The light will just stay on steady when you jump the connector.
If the light doesn't blink when you jump the connector, then your TCM (transmission control module) might be bad.
To verify this, remove the TCM ( it's located under the rug on the passenger side bolted to the firewall). You will find two modules bolted to one bracket. The TCM is the smaller of the two, on the right.
To remove it, you'll need to remove the 4 bolts securing the bracket. Then, unplug both computer modules, and gently remove the bracket.
Next, unbolt the TCM from the bracket.
Remove the four screws that hold on the cover.
Look at the board carefully. If it is bad, you will find a burnt out resistor and a leaking capacitor. Again, LOOK CAREFULLY. Yours might not be this bad. Sometimes just one of the resistors will overheat and turn dark brown.
With the ignition switch off, connect the two wires together. Have a pen and paper handy. Turn the ignition switch on. The S light (or D4 light if your car doesn't have the S light) should start to flash a code. Might be a combination of long and short flashes. A long flash stands for 10, and short flashes are 1. For example, if the light blinks: long-short-short-short, then that is a code 13. When you find out what code it is, post it and I can tell you what is going on. BTW, 90-93 Accords have a bad habit of burning out the trans computers. So sometimes you won't get a code. The light will just stay on steady when you jump the connector.
If the light doesn't blink when you jump the connector, then your TCM (transmission control module) might be bad.
To verify this, remove the TCM ( it's located under the rug on the passenger side bolted to the firewall). You will find two modules bolted to one bracket. The TCM is the smaller of the two, on the right.
To remove it, you'll need to remove the 4 bolts securing the bracket. Then, unplug both computer modules, and gently remove the bracket.
Next, unbolt the TCM from the bracket.
Remove the four screws that hold on the cover.
Look at the board carefully. If it is bad, you will find a burnt out resistor and a leaking capacitor. Again, LOOK CAREFULLY. Yours might not be this bad. Sometimes just one of the resistors will overheat and turn dark brown.
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