Hi,

what voltage should I have on the wires going into the wastegate solenoid at idle?

After replacing the vacuum pump, there's actually vacuum from the pump, but it doesn't get to the wastegate actuator. Since the tubing is ok, it can be either a wire still broken, or a failed solenoid. To figure it out, I'll measure the voltage on the wire going into the solenoid.


This drives me crazy; I already replaced some of the wiring of the solenoids and the vac pump, but it still doesn't work :/ Can this beast actually be that broken?

BTW, are all the solenoids on the solenoid bank the same, except for the wire plugs? They look pretty much the same, but the plugs are different.

My understandind is that the solenoid is run by a sqare wave, I'm not sure what voltage but surely its either 5 or 12. Have you tried changing the solenoid?

Thx! Before changing the solenoid, I'll have to buy one, thus I'll have to find out if there's any voltage at the wires at all in advance.

If I see reasonable voltage, I'll replace the solenoid, if not, I'll have to do something about the wires ...

BTW, do the solenoids close on voltage, or do they open? The solenoid is supposed to be fully open at idle, and if they close on voltage, my measurement will be rather pointless.

Lee,


WG solenoid pulse is 5-12v. check the ground too.


Solenoid is more likely at fault than PCM signal. they wear out due to atmospheric moisture.Edited by: quantum mechanic

You can test for voltage with a small light bulb. A meter probably won't read right.

The armature actually rusts to immoveable, as the release port is vented to atmosphere.


The 'signal' is +12v digital pulse, where Duty Cycle - on-time to off-time - is varied based on pressure signal from Boost sensor.


At idle, should be ~65% Duty Cycle, reading about 8-10vdc on DVM.


You can verify that it is not a hard DC level by switching voltmeter to AC Range, for ~6-7vac - depends on True RMS or Standard DVM


EGR Solenoids resemble WG Sol, but vent porting is not compatible with Wastegate duty.


EGR Solenoid vent 'metering' is different, EGR Vent Solenoid is not 'metered' vent.


WG Solenoid is 'metered' vent to atmosphere - prevents 'gate from blowing open when bleed is commanded.

Will it set a code or cause any other problems to unplug it? If not, I will send mine over there since it I don't use a vacuum pump anymore.

What pcm controled part doesn't set a code when you unplug it?


Edited by: quantum mechanic

Yea, you're pobably right but I will try unplugging it anyway. It seems like a waste just sitting there keeping the pcm happy when someone else could use it.

PCM sets DTC when over-Boost condition is sensed via MAP Sensor.


Condition must occur ~20 seconds to set DTC.


Hot-chips take care of the DTC, and the wired-in Boost adjust modification 'fools' the DTC.


WG Solenoid can be removed if PCM is 'chipped' or 'fooled', will not set DTC.


Will not damage PCM if removed with Ign Switch off - no power.

Thank you all for your input!

Whatnot, removing the wire from the solenoid will probably set a code and the SES light. I've seen that when I unplugged the wire at idle.

gmctd, will the PCM be damaged when the wire is unplugged at idle?


I'll probably get to measure it tomorrow afternoon, just was too tired for anything when I came home today. I'll keep you updated.

Ah, and they're taking about EUR 60 for a new solenoid here :(

PCM sets DTC when over-Boost condition is sensed via MAP Sensor.


Condition must occur ~20 seconds to set DTC.


Hot-chips take care of the DTC, and the wired-in Boost adjust modification 'fools' the DTC.


WG Solenoid can be removed if PCM is 'chipped' or 'fooled', will not set DTC.


Will not damage PCM if removed with Ign Switch off - no power.





I have a turbomaster on my truck so it doesn't affect boost at all.


I just went out and pulled the plug and it didn't set any codes. Is it likely to set one after a while or can the loose plug cause any problems?

Unplugging\removing WG Solenoid with power off will not damage PCM.


Running without WG Solenoid will not damage PCM.


Over-Boost DTC will set if PCM sees appropriate fault condition for ~20 seconds -


Boost greater than WG Duty Cycle command with rpm over 1800, fuel rate greater than ~20mm3


Need to plug vacuum line on EGR-equipped vehicles

Update:

I just measured the cables to the solenoid bank, engine idling: no current at wastegate solenoid, 12V on the other solenoids.

The wire of the WG solenoid is one of those I already tried to fix --- seems that I wasn't successful. I'll get into it tomorrow, hoping the solenoid is ok and just the wire broken ...

Lee, a broken connection would be a good find or you might have to replace the PCM.

Hm, if the only thing the PCM isn't capable of is controlling the wastegate, I'll probably switch to a mechanical WG control and sell the vacuum pump on ebay. That'll be much cheaper than replacing the PCM.

The new pump seems to be eating at the accessory belt because the pulley is too close to the pump. Seems that when you fix one thing, two other things fail on you, and you can't keep up with fixing ...

You can also test the PCM to see if it's the wire that's the problem. my manual shows C16 (grey wire) connecting to PCM and power coming from eng 1 fuse 20 amp (pink wire).


This might help. If that fuse is out, no power, I'd think.

The new pump seems to be eating at the accessory belt because the pulley is too close to the pump. Seems that when you fix one thing, two other things fail on you, and you can't keep up with fixing ...



Did you get the pump with the pulley already on it? It sounds like it was pressed on to the shaft too far. When I replaced mine a couple years ago (removed now) I pressed the pulley too far onto the shaft so I put washers between the pump and bracket so it lined up properly.

It works now :)

One of the wires of the WG solenoid was broken very close to the plug so that the piece of wire I replaced didn't fix it.

The WG actuator goes fully up and sits so tight that it's hard to move :)

Did you drive it at all after fixing it? If so, can you tell a difference?

Now that it's fixed you're good for 6 psi in the upper rpm. Time to plug the egr vac line and put 10K on the MAP.