Hi Guys,

Been a while since i have been on the forum and awaiting a password reset. However had a question I was hoping somebody can assist or shed some light on the way I should go with this issue.

I had a flat battery on my 04 warrior due to the interior light being left on, was in a hurry when discovered so just put a battery charger on boost and fired it up, since then the EML has been on and I now have no turbo boost.

I have checked with a few different code readers and I'm getting fault code 12 boost pressure system on the 2 out of 5 that read it, I have tried to clear this although as it is obviously an active fault it comes straight back on again.

When the engine is started EML light on, the VGT just sits on the stop and there is no movement from it at all, no turbo boost and basically very sluggish when under load, more noticeable 3rd gear and above on hills etc. for clarity there was absolutely no issue with this prior to the flat battery.

So far I have done the following and was hoping that someone can advise on where I should go next.

Removed the vacuum pipe at turbo with engine running and found no vacuum at this point, however I do have vacuum from the pipe at the back of the rocker cover to the solenoids.
Checked all vacuum pipework and hoses and confirmed no splits or blockages
Tested VGT actuator and EGR operational with a hand vacuum pump independently then with the solenoid energised with 12v supply.
Replaced the Turbo throttle valve solenoids
Replaced the maf sensor and boost pressure sensor

After this I then checked the voltage at the solenoid connections and found to be reading zero with the engine running, I have carried out a continuity test of the wiring from here down to the plug at the ECU and this all checks out fine. when checking the pins at the ECU however it is showing open circuit which made me think I had confirmed my suspicions that I had damaged the ECU when boosting the battery.

I then removed the ECU and sent it to a place to get tested telling them that it was showing fault code 12, they have now tested this and said the ECU is ok and returned, the fault is still present as I expected.

Now, I was just going to bite the bullet and send the ECU some place else to get checked as this fault is registered even before engine start-up and code 12 does state replace ECU im sure but there have now been a couple of times I used the car and once its hot I can turn the ignition off then re-start and the light goes out whereby I have vacuum at the Turbo and everything seems good except when I get upto 3rd gear and around 2400 RPM the light will come back on and everything stops working again.

The above intermittent part has only happened a handful of times and it is now essentially back to running with nothing working.

I am not the best with electrics but sure i can get to the bottom of it with some tips from someone that is.

Thanks
John

@123hotchef , @rob1307 @Heathen You all seem to understand the vac system fairly well, can you offer any advice?

@Rob1307 ( missed the capital R ! )

First question is did your use cheep Chinese solenoids off eBay as they have a tendency to work intermittently then fail , there is a test port on the back of the vac pump on the alternator and I’d check to see if you have the correct amount of vacuum from there.
When testing for power to the solenoid that controls the actuator it comes through in pulses and is not a constant voltage as it opens and closes to maintain the correct vac pressure. I’ve come across one l200 before that had a party blocked metal vac pipe that was causing issues with the turbo operation so it’s worth using a thin wire to poke down there to clean it out, at the back of the engine there are two metal vac pipes one is for the solenoids and the other I believe feeds the 4x4 system, take a vac reading from both of these pipes and see if you have a different reading between them, I’ve used a T piece before into the 4x4 vac pipe to the solenoids to also cure a turbo issue

Should add that I’m a bugger to get hold of sometimes so tag my name and I get an email reminder so I’ll get back as soon as I can 😁

I’ve had a quick check of mine and the vac figures I’ve got are 25 in-hg (imperial) 640 mm-hg (metric) that’s for a running engine so if you are near that it should be ok as mine works fine, if you hunt the manual down on here it should have the exact figures

[quote=""|p423537]First question is did your use cheep Chinese solenoids off eBay as they have a tendency to work intermittently then fail , there is a test port on the back of the vac pump on the alternator and I’d check to see if you have the correct amount of vacuum from there.
When testing for power to the solenoid that controls the actuator it comes through in pulses and is not a constant voltage as it opens and closes to maintain the correct vac pressure. I’ve come across one l200 before that had a party blocked metal vac pipe that was causing issues with the turbo operation so it’s worth using a thin wire to poke down there to clean it out, at the back of the engine there are two metal vac pipes one is for the solenoids and the other I believe feeds the 4x4 system, take a vac reading from both of these pipes and see if you have a different reading between them, I’ve used a T piece before into the 4x4 vac pipe to the solenoids to also cure a turbo issue [/quote]

Hi @Rob1307, sorry for the late reply in answering your questions.

Yes I did unfortunately buy the solinoids from EBay but believed from a Uk seller so made the assumption they would be good , guess that was my first mistake.

I did check all the metal pipe work previously individually with hand vac pump then basically by energising the solenoid and pulling a vacuum from the the pipe at the back of engine. I'm was quite confident this was all clear but will certainly go back and check with a wire and ensure everything is 100% clear, then measure the difference between 4x4 side and engine side as you suggested.

How would I go about testing these solinoids correctly to determine if faulty, I just put a 12v test probe on it to energise and had vacuum where required but didn't see any voltage at the plug you mentioned sends pulses, it was constant zero with engine at idle, I'm guessing I should get some form of reading here at idle as under normal circumstances the actuator would normally be off the stop at idle.

One thing worth mentioning also is that this fault code clears briefly with ign on engine off then immediately logs it again which was giving me the impression that it was a active code from the electrical side due to there being no vacuum available while engine off if that makes sense?

I'm away back to work now so won't manage to check the things you have suggested for a couple of weeks but will for sure once home.

Appreciate the help so far, apologies for all the new questions

John

Tag me back in once you’ve had a look and I’ll have a look at mine to see what voltage signals I get and report back, doesn’t matter how long it is between posts as long as a solution is found to your problem 👍

Hi @Rob1307, just back home and had a chance to look at my jeep again with the following results.

Checked Vacuum at the Vac pump and found to be good @ 620 mm-hg -24 in-hg
Checked Vacuum at the back of the cam cover to the solenoids @ 620 mm-hg -24 in-hg
Checked Vacuum at the back of cam cover to the 4x4 system @ 620 mm-Hg. -24 in-hg

I checked the metal pipe work as you suggested only one that was possibly partially blocked was from the inlet manifold to the boost sensor but I think was clear enough as hasn't changed the condition, assuming the new sensor works.

I checked the engine codes logged again and found my diagnostic machine is now picking up the correct codes after an update which helps.

Code 12 - Boost Sensor
Code 41 - Throttle Valve Solenoid
Code 52 - VGT Cont Press

Code 12 was my original problem so was expecting that and I would say the others were logged purely due to me disconnecting the plugs and checking the solenoids previously.

Cleared all codes

After the codes had been cleared and at idle I noted that the VGT solenoid was operating and I had vacuum to the turbo and sensor but the throttle solenoid was not being energised

With Ignition on Engine off I recorded the following
Boost Sensor 53.2 KPA
Throttle valve solenoid 1 - off
VGT cont Press 94.7 KPA

With engine running reading live data I had the following
Boost sensor 52.3 KPA ( No Change)
Throttle valve Solenoid 1 - Off ( No Change)
VGT cont Press @idle 51.3 KPA @2k rpm 57.7KPA @3k rpm 62.2KPA

I took the jeep for a run while logging the live data readings and found that the boost sensor and baro pros sensors remained the same readings no matter what load the engine was under, also not once did the throttle solenoid turn on ?

Also due to being for a drive code 12 was back and all vacuum to VGT etc stopped ( guessing over boost )

Once codes cleared at home I get the vacuum back to turbo and sensor.

I've checked both Soleniods are operational with 12v supply and all lines operating as confirmed with hand vac pump, I am supposed to be getting a shot of a boost sensor from a friend tomorrow to hopefully check and see if there is any change compared to the new one I bought from eBay with the solenoids.

Can you confirm if the throttle solenoid should be showing a change in state and when this happens?

Thanks
John

Hi @Rob1307

Update on the jeep, I managed to find a manual online with what the sensor voltages, resistance etc should be under normal conditions and have now got to the bottom of the issue.

Basically code 12 flags the map sensor as being unhealthy which in turn shuts down operation of the VGT Soleniod and the egr system for protection I guess.

When looking at the live data I could see that the Barometric pressure prior to start up was reading 101 KPA but the Map sensor was only reading around 52 KPA with same condition at idle this was the reason for the code 12 as they should be around the same atmospheric pressure, after doing the electrical checks on various sensors which checked out ok, I discovered applying positive or negative pressure with a pump to the map sensor made no change to the Map sensor KPA reading on the live data.

When I carried out the same voltage checks at the ecu connectors I noticed the connector pin required for checking the Map sensor voltage was tied into the ralliart performance upgrade control box via a jumper loom, I disconnected that and plugged the original loom connector back into the ECU and all functions returned with the correct KPA matched between Barometric sensor and MAP sensor, code 12 now gone and the truck is back to running how it was previously so obviously something within the Ralliart box that tells the ECU the MAP sensor is healthy has failed giving me this issue.

Might look to see if I can have the Ralliart box repaired or find a 2nd hand one to put it back to how it was in the long term but glad it's fixed.

Thanks for the help anyway regarding the vacuum pressures previously, thought I should do a wee write up Incase anyone else experiences the same issue for future reference.

John