2000 motor transplant to my 99 egr issues? HELP

MistybluQQ · Feb 7, 2011

well i transplanted a 00 motor into my 99 because i snapped my camshaft. i had to change most of the sensors and the injector rails. i have everything working except the EGR on the manifold. it is not the same as my 99 and i cant just change the air intake manifold. i need to know if there is a modification i can use to make the 00 egr work on my 99 system. the plug appears the same. i dont want to take out the injection manifold lot of work. please help. ps i have a 00 injector rails if any one needs one.

Starship · Feb 8, 2011

Welcome to the forum.

Are we talking about trying to fit a 99 EGR valve onto a 2000 intake manifold? Why not just use the EGR valve that came with the motor? As you stated, the plug is the same, so is the wiring to the PCM and thus you should be able to connect it up. These EGR valves are relatively primitive devices. They have two circuits, one for the PCM to control the EGR solenoid and the other one for feedback on the solenoid operation. About the only thing that could be different is the flow rate. In fact, you can just block off the EGR port with a metal plate, mount the EGR valve on top of it, and the PCM probably wouldn't know the better.

RalphP · Feb 8, 2011

Starship said:
Welcome to the forum. Are we talking about trying to fit a 99 EGR valve onto a 2000 intake manifold? Why not just use the EGR valve that came with the motor? As you stated, the plug is the same, so is the wiring to the PCM and thus you should be able to connect it up. These EGR valves are relatively primitive devices. They have two circuits, one for the PCM to control the EGR solenoid and the other one for feedback on the solenoid operation. About the only thing that could be different is the flow rate. In fact, you can just block off the EGR port with a metal plate, mount the EGR valve on top of it, and the PCM probably wouldn't know the better.

One other thing that can be fixed with a quick tune:

Depending on the vintage and which design, the EGR Control A signal is longer or shorter - to where if you swap in a 1999 PCM into a 2000 or later, it can cause errors (specifically, the code I get - which is "Control A Signal Low or Too Short".) Add to that the fact that replacement ACDelco EGR valves have an even SHORTER than original Control A signal on startup, and ...

Why, yes, I DO drive with a Check Engine light most of the time due to this, why did you ask? (Also an occasional O2 sensor error - that's on the list, but it'll take a PCM tune to fix the usual error.)

RwP

Starship · Feb 8, 2011

Hmm, what exactly is the DTC you're referring to and in what combination (2000 motor and which EGR valve vs. which PCM)? BTW, I keep saying "solenoid" when I really mean pintle, a force of habit.

MistybluQQ · Feb 8, 2011

Starship thanks. i have the 2000 intake and egr in the car and connected. i get a p0404 and a p1404 which contradict each other i think the pcm doesnt understand the information that the 2000 egr is telling it. i cant just change the sensor the intakes are completely different. how can i resolve the issue and get it to correctly function?. can the pcm be reprogrammed to see the 2000 egr?

Starship · Feb 8, 2011

Oh, jeez, that means the 1999 and 2000 EGR valves are sufficiently different electrically as RalphP alluded to in his post. The feedback the PCM is getting is obviously out of bounds, i.e., the pintle position voltage doesn't match the solenoid control exerted by the PCM. I don't know what to say, I learn new things everyday on this forum.

I'm afraid your options are rather limited:

1. Fashion an adapter plumbing to make use of the 1999 EGR valve
2. See if the PCM can be recalibrated (doubtful)
3. Swap UIM (a lot of work)
4. Swap PCM (a lot of work to undo)

Also, if you could get a waiver on the emission testing, you could just drive it like that. The lack of EGR isn't going to ruin the engine (it may run a little hotter and the PCM may throw lean DTCs).

Starship · Feb 9, 2011

Just out of curiosity, I wonder if you could measure the resistance between terminals A and E on the EGR valves, both at the same temperature, and post the values. That'll give me some idea of the differences on the solenoid coil side. Of course, that is only if you feel like it.

RalphP · Feb 9, 2011

Starship said:
Hmm, what exactly is the DTC you're referring to and in what combination (2000 motor and which EGR valve vs. which PCM)? BTW, I keep saying "solenoid" when I really mean pintle, a force of habit.

DTC is P0405 - EGR valve on the car is an ACDelco 12581876 . The module under the glove box, in front of the blower motor, is an I dunno offhand (don't feel like crawling outside and tearing the sound deadening panel off to read the numbers off of it, but it DID come off a 1999 ... )

Past that, I can't help any.

Didn't discover this as a problem on the 'Bu, but it's been reported on the Impalas with the 3400 - and I extended it as an assumption, especially since it started after I swapped the three (!!) in a row 12581876 EGR valves. And then discovered that yes, it does produce a shorter Control A signal than the original .. and the original is shorter than the 1999 one! Grrr ....

RwP

Starship · Feb 10, 2011

"The module under the glove box" is the BCM which shouldn't have anything to do with the EGR. And, I'm not sure about the "Control A" part. You're probably inferring from the pulse width modulated, 12V signal for solenoid control. 12V signals are expensive to keep track of.

P0405 is supposed to be "Exhaust Gas Recirculation Sensor 'A' Circuit Low." I gather this is something different from the OP's problem (mismatch between command and feedback). The PCM supplies the ground and 5V reference voltage to EGR terminals B and D, respectively, and expects a sense voltage on C that corresponds to the pintle position. This sense voltage should never go to 0V (there's a minimum the potentiometer can go) which is what the DTC says happened. You may want to check your wiring when you get a chance (also applies to the OP's 1999):

SENSOR GROUND: EGR terminal B BLK <--> PCM C1 terminal 31
EGR POS SIGNAL: EGR terminal C BRN/WHT <--> PCM C2 terminal 28
5V REF: EGR terminal D BRN/WHT <--> PCM C2 terminal 30

EGR SOL VALVE: EGR A GRY/BLK <--> PCM C1, 32
EGR VALVE CTRL (BATT V): EGR E RED <--> PCM C2, 4

MistybluQQ · Feb 10, 2011

ok i tested the two egr the 1999 egr was 8.3 ohms and the 00 egr was 6.8 ohms at roughly the same temperature. also i am having the 00 computer sent to me from the car i got the motor from. i think the o2 sensors are different too on the 00 does anyone think the 00 computer will help or will it show me other issues then?
P.S. ralph thanks for the pinout information any good advise is appreciated

Starship · Feb 10, 2011

MistybluQQ said:
ok i tested the two egr the 1999 egr was 8.3 ohms and the 00 egr was 6.8 ohms at roughly the same temperature. also i am having the 00 computer sent to me from the car i got the motor from. i think the o2 sensors are different too on the 00 does anyone think the 00 computer will help or will it show me other issues then?

2000 motor transplant to my 99 egr issues? HELP

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