Rep Power: 0

Not sure if im posting in the right board.. Let me know, thanks.

Running into some massive problems with my 2001 civic Si. Yesterday I cut the AC belt not realizing that it was attached to the alternator. Reason for cutting the belt was due to an obnoxious squealing.

After cutting the belt, I drove for about 15 minutes (without an alternator)

Once I got to where I was headed, I put a new AC belt back on.

Everything seemed fine, there was no longer any squealing. After driving for about 40 minutes I parked my car. I revved it a bit and all of a sudden the car began backfiring, bogging, and idling extremely low.

Now when I try and drive it I've noticed that the tachometer is completely unresponsive. Speedo is fine. The car also doesn't seem to rev above 3,000 RPM (estimated). Once the car hits 3,000 it hits rev limiter and wants to stall out.

While driving the car is very hesitant to go above 3,000. The car begins to rock back and forth very slightly. Check engine light is on and battery light comes on and goes off after about 30 seconds of running.

Also, something odd to be noted--After owning the vehicle for two years, the DTR lights never worked until today when they decided to randomly turn on and begin working. When this happened the tach light went off.

ALSO: have tried using three different scanners to get diagnostics and all three said error: cannot connect to car.

I have a full shop at my disposal and any advice would be extremely helpful. Thanks a lot guys, looking forward to your responses.

 
Rep Power: 186

By running off the battery and with no Alt. belt, you may have fried your ECU/computer or it was already fried from the squealing/loose Alt. belt. That would explain your error messages when you try to read codes. You were probably better off leaving the squealing belt on until you could replace it without running the car.

I'd wait until tomorrow and see if ezone chimes in with a better answer.

 
Rep Power: 518

This was with the engine not running, correct? Too late, it's a goner.


That would cause low voltage. That can't fry the PCM.

OP probably didn't tighten the big bolts for the alternator after installing the belt.
This is what normally fries the PCM.
Click this link (PDF) and read: Engine Won%u2019t Start? Check
for Loose Alternator Bolts
Symptoms can vary a lot, the cause is the same.

You need to correct the alternator mounting bolts first.
May as well clean up all the chassis grounds between the battery/body/engine while you are at it.
Then it needs a new PCM.
And probably a tow to a dealer to get it programmed. Take all your keys.

Erm....Maybe you should just close the hood and back away slowly.

 
Rep Power: 0

Yes the car was off when i tried the scanners...and there was a bolt loose on the alternator so i tightened it and the alternator is still charging the battery, so i think thats fine (belts not loose) but the car still has the same symptoms.

 
Rep Power: 518

I'm sure it does.

It's too late to save this PCM, the damage is already done.

 
Rep Power: 0

is there any test i can perform on it to make sure before go get a new one just to make sure...also im looking up the pcu and the parts guy is asking for the engine designation. he is asking if its a d17...do you have any idea?

 
Rep Power: 518

Read the info I linked yesterday.
It's YOUR car, not mine. You don't know what engine is in it?

A Honda dealer should just use your VIN to look up the part.

 
Rep Power: 0

i know the motor size but ive never heard of engine designation. and ok i will thanks for your help

 
Rep Power: 511

Are you in Canada or US?

In the US, the Si is a 2.0L hatchback. That one is equipped with the K20A3 engine.

In Canada, the Si is a 1.7L coupe/sedan. That one is equipped with the D17A2. The Canadian Si is equivalent to the USDM ex