What is the danger of not replacing the Powertrain Control Module?

VPK

MEMBER
2002 TOYOTA SIENNA
16,700 MILES

My check engine light just came on today. I was expecting something minor and was told I needed to replace the Module engine control and if that doesn't work I might have to then replace converter and center pipe. What happends if I don't replace the Powertrain Control Module will the computer just die and the car stop? I'm not having any obvious symptoms except the idle is a little off.

Thursday, October 13th, 2011 AT 1:06 AM

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

First of all, you need a second opinion. It sounds like they are guessing.
You need to give us the code so we can further help you.

Roy

Was this

answer

helpful?

Yes

No

Thursday, October 13th, 2011 AT 1:20 AM

VPK

MEMBER
2 POSTS

My code was P0420 but due to some Technical Service Bulletin the one service rep said I needed to replace my Engine Control Module (10/19/2005TSB) which would cost $1561.83. Then if that didn't work I needed to replace the entire catalytic convertor and center pipe which would cost $2591.24. I just talked to a local muffler shop and they said they could cut out the catalytic convertor and replace it for $186- I'm trying to figure out if that will be sufficient. It's much more in my price range. When I called back the dealership the other technician said he'd never seen anyone need another whole computer that the catalytic convertor takes care of it.

Was this

answer

helpful?

Yes

No

Thursday, October 13th, 2011 AT 12:40 PM

ASEMASTER6371

MECHANIC
52,797 POSTS

420 is a cat code. It has failed and needs to be replaced. You need a cat that will keep the light out, not a 186 cat. Factory is expensive at about 750 plus 1.2 hours in labor.

Shop around at other shops. Dont worry about the pcm right now. I think your only issue is the cat.

Roy

Was this

answer

helpful?

Yes

No

Thursday, October 13th, 2011 AT 12:45 PM