DTC 1406----Info on repair

Hey giys,
I just wanted to post this, incase anybody else has the same issue:
I had a DTC 1406. EGR valve pintle position. Hooked the car up to my tech 2 and saw that when I commanded EGR duty cycle its commanded and actual value didnt move and that the RPM didnt change. No big deal bought a new one at cost for $90. Put it on and after 3 ign cycles it came back with DTC 1406' WTF!. Put the tech 2 back on it and now when commanding EGR duty cycle the RPM changes, but the desired and actual dont change. Jumped pin A from the EGR connector to groung and watched the voltage on a meter and the scan tool change. Long story short the quad driver in the PCM has gone on permanent vacation. There are no other driveability issues except the CE light and theres no EGR duty cycle which is no big deal but the CE light is always on. Just wanted to post this as I have seen some other post on here about DTC1406 and wanted to let others know that a bad EGR can blow out the quad driver.
HTH,
Thanks,
John

Also, I was wondering what other PCM could I interchange with? EX bonneville SC, park ave SC, etc....
Thanks

First off thanks for the Tip on the EGR and PCM.

Your best bet would be to contact Morads for a used 1995 Riviera PCM.
He has had a few 95's in recently and probably has one for you.
www.moradspartscompany.com or cal them at
216-798-6902
216-671-3736
I usually call Erik McMillan at the above # and ext#202

This is good to know - so you're out an EGR vlave *and* a PCM?!?!?

As far as exchanging PCMs, there are a lot that are plug compatible *but* no matter which one you get it has to be reprogrammed.

I suggest getting a replacement from Rodney Brenner if you don't want one from Ed Morad for whatever reason:

spareECM
4371 McCance Circle
Fredricksburg OH 44627
(330) 473-0426

Call during "Banker's Hours" or email him at selectcore@aol.com; he sells checked/tested/recovered ECMs on eBay and has a shop with programmer to set them up with your make/model/VIN. Basically you give him your VIN and cash and he ships you working ECM. I bought a used ECM off Rodney, worked fine.

Alternatively if you pull one yourself out of a junkyard, most larger shops can reflash them no problem.

What to do: Your PCM is mounted behind the glovebox. If you pull it you'll find the P/N on the case which should be 16236257 I think. IRIC it went into the PA, Regal, Lumina, Malibu, Monte Carlo, Century, Olds 88, Achieva, Alero, Bonneville, Grand Am, Grand Prix and other GM cars. So it should not be hard to get one... From a parts dealer I'd expect them to come in around $150 - $200 including core.

,

Albertj

I got a used one from Morad's some time ago, cost me $75.00 shipped and all I had to do was a CASE Learn.
Also, JD94SS has a Tech 2 to use for any programming updates or whatever.

so info on quad drivers, the quad drivers are protected by a circuit breaker internally so if there is a problem with any sensor (shorted or open) it will not burn them out.
find the culprit and "reset ecm" and all should be good.
unfortunately ecms still can go bad. Ive put 3 different ecms in my riv and still had a quad driver failure. turned out to be the boost solenoid was shorted.

Yea Im out and EGR and due to the EGR now a PCM as well. Thanks for the info on interchange. I just called a few guys and found one for $70. Woggy i agree with you. TSB was out staing to check for amperage across PCM terminals to ground while unplugging various sensors to see which sensor is the culprit. Also thanks for the heads up to Morads wbsite. Thanks again guys for the info I really appreciate it.

JD94SS,
What is the number of the TSB that describes the problem.?
Thanks,
Rick

It describes checking for amperage at the PCM due to faulty sensor blowing out the driver. Amperage is check across suspecting pins.