Stranded with "engine not available" trouble code

In reply to Pete. (l33t FS) :

Soooo... it sounds like what you're saying is that in the automotive world as so many other places, as long as there is an existing answer for how to do something, we don't start unraveling the sweater of how to do it better, and knowledge about what does not work evaporates with the last person who was here the last time that was the answer we were using.

These are the codes I saw when I scanned today. To me, it looks probable it's a shorted out EGR. All other circuits now look happy with a new fuse and the EGR valve unplugged.

Codes after unplugging EGR and replacing fuse, but BEFORE clearing any codes:
Hard trouble codes:
P0030 Heated O2 sensor heater control ckt malfunction
P0031 Heated O2 sensor - heater control ckt low
P0597 Thermostat heater control system ckt open
P0958 Thermostat heater control system ckt low
P06DA Engine oil pressure control ckt
P06DB - could not find

Pending codes:
P0403 EGR control ckt malfunction
P0405 EGR sensor A ckt low - valve position sensor A low
P0443 Evap emission control purge valve ckt
P0458 Evap valve ckt low
P0489 Exhaust gas recirculation (EGA) system ckt low

Pending codes AFTER clearing fault codes  (still unplugged EGR and good fuse)
P0403 EGR control ckt malfunction
P0405 EGR sensor A ckt low - valve position sensor A low
P0489 Exhaust gas recirculation (EGA) system ckt low

I found 3 different part numbers on the Volt forum, only one shows available, but has zero fitment info. I'd be willing to bite the bullet if I could confirm it was the right part for the car. But otherwise it's a big risk with I think a no refund policy (electrical part).

Anybody able to confirm the correct EGR valve part number for a 2017 Volt?

Forums have:

12691147  orig pn

19436113  new pn

19436521  new new pn that shows some availability - $1100

enginenerd said:

In reply to rslifkin :

...Car would blow a fuse labeled 'fuel pump' repeatedly. I'd replace the fuse, it would start and run perfectly fine but any time I started moving it would die within a few feet...

Fuses protect the wiring and are an indication that something downstream drew too much current. Replacing only the fuse is a guaranty of the same thing happening again.

$1100 for an EGR valve. Ouch. Sorry I can't help with part numbers but I'm commiserating with you as a fellow Volt owner. I love the car but hope I don't have any trouble with it! 
 

It does drive better than a Prius. And the all electric range is definitely better. 

sevenracer said:

These are the codes I saw when I scanned today. To me, it looks probable it's a shorted out EGR. All other circuits now look happy with a new fuse and the EGR valve unplugged.

Codes after unplugging EGR and replacing fuse, but BEFORE clearing any codes:
Hard trouble codes:
P0030 Heated O2 sensor heater control ckt malfunction
P0031 Heated O2 sensor - heater control ckt low
P0597 Thermostat heater control system ckt open
P0958 Thermostat heater control system ckt low
P06DA Engine oil pressure control ckt
P06DB - could not find

Pending codes:
P0403 EGR control ckt malfunction
P0405 EGR sensor A ckt low - valve position sensor A low
P0443 Evap emission control purge valve ckt
P0458 Evap valve ckt low
P0489 Exhaust gas recirculation (EGA) system ckt low

Pending codes AFTER clearing fault codes  (still unplugged EGR and good fuse)
P0403 EGR control ckt malfunction
P0405 EGR sensor A ckt low - valve position sensor A low
P0489 Exhaust gas recirculation (EGA) system ckt low

 

I found 3 different part numbers on the Volt forum, only one shows available, but has zero fitment info. I'd be willing to bite the bullet if I could confirm it was the right part for the car. But otherwise it's a big risk with I think a no refund policy (electrical part).

Anybody able to confirm the correct EGR valve part number for a 2017 Volt?

Forums have:

12691147  orig pn

19436113  new pn

19436521  new new pn that shows some availability - $1100

If you want to PM me your VIN I can go to our parts department (I work at a GM dealer) and confirm the part number for you.

In reply to NickD :

PM sent thanks!

dculberson said:

$1100 for an EGR valve. Ouch. Sorry I can't help with part numbers but I'm commiserating with you as a fellow Volt owner. I love the car but hope I don't have any trouble with it! 
 

It does drive better than a Prius. And the all electric range is definitely better. 

There's been supply issues on these for years. Lots of stories about people waiting for months for EGR valves, and dealer pricing around $3900 to replace.

NickD said:

sevenracer said:

These are the codes I saw when I scanned today. To me, it looks probable it's a shorted out EGR. All other circuits now look happy with a new fuse and the EGR valve unplugged.

Codes after unplugging EGR and replacing fuse, but BEFORE clearing any codes:
Hard trouble codes:
P0030 Heated O2 sensor heater control ckt malfunction
P0031 Heated O2 sensor - heater control ckt low
P0597 Thermostat heater control system ckt open
P0958 Thermostat heater control system ckt low
P06DA Engine oil pressure control ckt
P06DB - could not find

Pending codes:
P0403 EGR control ckt malfunction
P0405 EGR sensor A ckt low - valve position sensor A low
P0443 Evap emission control purge valve ckt
P0458 Evap valve ckt low
P0489 Exhaust gas recirculation (EGA) system ckt low

Pending codes AFTER clearing fault codes  (still unplugged EGR and good fuse)
P0403 EGR control ckt malfunction
P0405 EGR sensor A ckt low - valve position sensor A low
P0489 Exhaust gas recirculation (EGA) system ckt low

 

I found 3 different part numbers on the Volt forum, only one shows available, but has zero fitment info. I'd be willing to bite the bullet if I could confirm it was the right part for the car. But otherwise it's a big risk with I think a no refund policy (electrical part).

Anybody able to confirm the correct EGR valve part number for a 2017 Volt?

Forums have:

12691147  orig pn

19436113  new pn

19436521  new new pn that shows some availability - $1100

If you want to PM me your VIN I can go to our parts department (I work at a GM dealer) and confirm the part number for you.

GRM WINSa!!!!

Talked to our parts department; part number for a new one is 1943652. The price is eye-watering and it is indeed backordered, and while there are some out there in the country, I was told by our parts guys that pretty much any dealer that has one won't part with them, because they're so scarce. I guess we had a tech that needed one, and it was like pulling teeth trying to get one, unfortunately.

Just a thought; will it run with the EGR valve unplugged? If the valve is internally shorted or whatever and knocking a bunch of stuff out, it may run with it unhooked, albeit with a check engine light. Might be worth a try

In reply to NickD :

Thanks!!!

Yeah, it seems to run ok with egr unplugged, just has a check engine light.

Not sure if that willcause problems long term,  but mostly just run on battery. So shouldn't  see much run time on gas.

So,  I found a pinout of the connector, and  plan to ohm it out tonight and look for shorts.

I hate to just throw parts at it, but it seems like it likely is a shorted egr. There is a different egr code that some people get, related to reduced flow, P0401 maybe. Which might not require a new egr, bur that's not what I'm seeing.

Is it dumb to order the egr at this point? Anything else to check first?

I would say, probably not a bad idea to get an EGR valve. Talking to the EV techs here, it's not an uncommon failure, and your symptoms are a pretty dead-on match.

Here's the pin out I found.  Was not able to confirm any shorts. Pins are not easily accessible for probing, blind and close to core support. I tried to bodge together a pin header, but don't know if it was contacting egr pins.

I'd put an inline fuse on the EGR. That way if it shorts again the inline fuse pops, and you'll just get a CEL for EGR codes. 

Just because it's not blowing the fuse now, doesn't mean that it won't when it gets hot, or is actuated electronically.

I like the secondary fuse idea!

I like the idea.

Replace factory fuse with slow blow, added egr fuse fast blow?

Or can a lower amp egr fast fuse be relied upon to pop first?

Probably just a standard fuse inline.

I'd do some research and testing to find out what specifically is shorting and use a meter to determine actual load being used by the EGR circuit alone (hot) and use a 1.5x fuse. 

Specifically I'd want to know if the valve is operated by an ECU controlled output directly, and if that output is losing power separately from 5vref or they go together. 

I don't know if that's actually a thing or not, but modern stuff is so interconnected I'd want to be sure I'm positively isolating the necessary circuits before just tossing a fuse on the 5vref and calling it good. 

I havent thought through this in depth, but it seems like the fuse that blows is just feeding pin 1, "powertrain main relay fused". So overcurrent condition on +12v supply to the egr.

I would think the 2 pwm signals and the ref low signal would come straight from the ecu. If they shorted it would take out whatever ecu ckts arent protected, not the fuse.

There is a small control module in the EGR valve.  It gets power and ground, the PWM Input wire is the signal from the PCM (ECM?) to tell it how much to open, the PWM Output is the signal back that gives actual position information.

If you had a scantool with bidirectional controls, and an amp clamp on a multimeter, you could run a looped fuse in the fusebox for the fuse that blows with the EGR valve unplugged to see what current the other things are drawing, then plug it it and use the scantool to open the EGR valve to see how much current the EGR valve adds to the circuit.  Then add your inline fuse as a value a little higher than what the EGR valve draws, assuming that it's working okay at this time.

I like doing the looped fuse method because it is waaaaay easier to stick an amp clamp there then it is to unloom wiring, somewhere deep where you can't get to anything.  Two spade terminals on an inline fuse holder is all you need.  And now you've made another tool!

Part of me, the hardware hacker part, wonders if the EGR Input and output are the same square wave and you couldn't just unplug the valve and loop those lines together.  You'd probably end up with a P0401 though (I think) when the computer doesn't detect a MAF signal drop/MAP rise to indicate EGR flow.

Edit: That probably wouldn't work if the system needs a 5v pullup, nevermind.  Fun to think about though.

In reply to sevenracer :

The reason I'm recommending more detailed analysis is because it seems fishy that blown fuse would mess with 5vref. Suggests to me there's something else going on, or it just hasn't been explained well here (or my limited reading comprehension is screwing with me 😅)

Based on the name of that fuse's circuit, I suspect that something in the EGR might shorting both the power feed side /and/ the 5vref. If that's the case, you'll need a way to isolate the 5vref from the EGR when the fuse blows. 

I suppose you could answer that by pulling the fuse with the EGR unplugged and see if it still runs and the ECM still sees all the sensors then plug the failed EGR back in and see if the ECM still sees everything like it should. 

If it still runs and drives with a blown fuse and the EGR unplugged, one could create a failsafe by adding a relay controlling the 5vref with the trigger tied to that fused circuit so the 5vref gets isolated if the fuse blows. 

Hopefully that makes sense. I'm typing this past my bedtime.

In reply to Pete. (l33t FS) :

I'll have to make a note of that looped fuse technique. That would save a lot of time in some situations.