code 406 EGR

[de_lok]

I cant seem to make this code (406) go away ! "EGR Sensor Circuit High Voltage" From all information I can gather the MAP sensor on the firewall needs to be repalced. Well I installed a new one (part store let me try it), cleared the code, and test drive. Light stays off as long as I drive, no matter how long I drive, but pops back on emediatly after the next startup! Same with old or new MAP/Baro. Removed and thourghly cleaned the EGR and checked vaccum lines for leaks. HELP ! ! ? ?

[Turbine Doc]

Check the EGR solenoid, Firewall baro acts a a EGR position feedback after startup, looking for changes to vac flow, if no vac then firewall sensor will see no change, put a tee in line with vac gage supplying EGR valve, run long hose on gage into cab(don't pinch the hose & deadhead the reading), and report back what vac reading you have driving & at idle.

Shame we are at opposite ends of the state or I'd pop by and give you a hand.

[de_lok]

Thanks Tim! I went to Auotzone and picked up a vaccum gage and tried several things.

1) tested main vac line from pump to EGR sol. reading 0 to 1" hg at startup and topped out at 5" hg @1600 rpm.

2)Tee'd in on vac pump side of EGR sol vlv and had same reading.

3) Tee'd in on EGR/MAP side of EGR sol vlv and no noticeable gage movement at startup, or driving down the road. However if I reved the engine up to 1500 rpm or so in neutral the gage would move between 0 and .5"hg.

Should I check voltage to that solenoid before replacing it?

I dont guess we could live in the same state and live this far apart !

Dewayne

[JohnC]

Originally posted by de_lok:
1) tested main vac line from pump to EGR sol. reading 0 to 1" hg at startup and topped out at 5" hg @1600 rpm. Go no farther. If this is what you say, the vacuum pump is shot. Or, possibly, a hole in the line from the pump. You should see about 20 inches of vacuum here at idle.

[de_lok]

JohnC
I connected the vaccum gage this time directly to the vaccum pump. There is a heavy (1/2" dia) hose connected to the pump and routes behind the alt. where a 1/8 dia. white hard plastic line connects in. I disconnected the white line and connected the vaccum gage line in there. Same reading as before, almost no vac at idle and a max 5" at 1500 rpm or more. I should mention the 5" reading was only reving the engine in neutral. Almost no vaccum reading driving down the road.

Looks like a vaccum pump? :confused:

Dewayne

[Turbine Doc]

Looks like with those readings vac pump is toast,

I have some ideas for you, I'll get Jim B to hook us up email wise and we can chat 1 on 1

[de_lok]

Replaced the vacuum pump today. A local auto parts store had a reman in stock ! ! ! SES light is out and hasnt come back on after a dozen or more restarts, NO CODES ! ! Thanks guys for the help and happy new years ! :D

[de_lok]

Sure Tim, even though I have this one fixed it would be cool to chat of thread, and thanks for the vacuum testing tips. Your tips and JohnC's info on 20"hg at idle did it for me! :D

[de_lok]

Tim
My email is de_lok at yahoo dot com