Multiple Codes - ECM Failing?

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Apr 14, 2009 | 03:21 PM

jimg's'93

Thread Starter

Drifting

Joined: Nov 2005

Posts: 1,324

Likes: 5

From: Charlotte NC

Multiple Codes - ECM Failing?

Within the past 2 months I replaced my opti (yes, a very cheap one I say with head bowed) and replaced my injectors. She ran like a top for about 2 weeks after the opti replacement, but now misses, runs roughly, poor throttle response and a very rich mixture.

The codes I'm pulling are:

DTC 33 - MAP High Volt/Low Vac
DTC 36 - Dist. Faulty High or extra low res pulse
DTC 72 - Gear selector switch circuit
DTC 74 - NO IDEA??

I will be testing these circuits for the MAP and Opti this weekend to see if indeed there are component issues, but what is a DTC 74? It's not listed in my FSM at all.

Also - I'm concerned I might be losing my ECM as the gear selector and O sensor codes have intermittently shown up and disappeared over the years.

Any thoughts to keep me focused in a proper direction here? BTW, I have no Tech 1 or similar, I use a good old Muti-meter.

Thanks all.

Jim

Apr 14, 2009 | 10:40 PM

jimg's'93

Thread Starter

Drifting

Joined: Nov 2005

Posts: 1,324

Likes: 5

From: Charlotte NC

Well, thanks for the overwhelming responses. First time I've ever posted on the 'scan & tune' side. I did replace the MAP sensor today and she runs beautifully. Let this post die.

Apr 15, 2009 | 10:27 AM

Epimax

Burning Brakes

Joined: Dec 2007

Posts: 1,068

Likes: 6

Here ya Go!

I don't get over here that often either.. Stopped in looking for a Tech-1

Apr 15, 2009 | 12:19 PM

jimg's'93

Thread Starter

Drifting

Joined: Nov 2005

Posts: 1,324

Likes: 5

From: Charlotte NC

Thanks Epi! Curious as to why that's not in my FSM, but I've got it now. I did have a failing battery just before I replaced the opti. That must be how that 74 posted.

Thanks again!

Apr 15, 2009 | 02:52 PM

Epimax

Burning Brakes

Joined: Dec 2007

Posts: 1,068

Likes: 6

Quote:

Originally Posted by jimg's'93

Thanks Epi! Curious as to why that's not in my FSM, but I've got it now. I did have a failing battery just before I replaced the opti. That must be how that 74 posted.

Thanks again!

You Bet! I've got the 2 volume FSM at home, but I use the alldatadiy.com site as well. It's an online service and seems to have the same info as the FSM, -as well as technical bulletins, etc, and with the search function it's a lot easier to find what you're looking for too!! That's where I pulled up the Code 74 info earlier!
I use it for all the cars!