So what do you guys make of P0299?

Sir Sam · **Posted:** Mon Aug 13, 2007 9:40 pm

"P0299 Turbo/super charger – low boost Mechanical fault "

hmmmm, i wonder whats going on......

DZL_LOU · **Posted:** Mon Aug 13, 2007 11:22 pm

P0299-BOOST PRESSURE SENSOR POSITIVE DEVIATION
When Monitored: With the engine running.

Set Condition: Actual boost pressure differs from the boost pressure setpoint by more
than 1000 hpa.

POSSIBLE CAUSES

BiodieselJeep.com · **Posted:** Tue Aug 14, 2007 8:52 am

remember, last two numbers could be flipped if you are doing the key trick. I don't think they are flipped on a scanner.

I'm not going to guess airfilter, you just changed it. I'll vote on the hopeful side for air-leak....something rattled a hose loose. Happens a lot.

Sure hate for it to be the turbo...you deserve a break after all you did! PLus, I would think a couple of other codes would pop if the turbo was going.

Johnboy · **Posted:** Tue Aug 14, 2007 12:33 pm

I had the same code when the EGR went out. When it happened, I had 2 codes, EGR and turbo...Dealer replaced EGR and no CEL since.

Jeger · **Posted:** Tue Aug 14, 2007 1:20 pm

lets see...would that be P0299 or P0299

If nothing is obviously wrong, pull off the little filter for the boost control...right behind the air box..it that fixes it put a new one on. Maybe it got goofed up when it was rolled?

Sir Sam · **Posted:** Tue Aug 14, 2007 2:40 pm

BiodieselJeep.com wrote:

remember, last two numbers could be flipped if you are doing the key trick. I don't think they are flipped on a scanner.

I'm not going to guess airfilter, you just changed it. I'll vote on the hopeful side for air-leak....something rattled a hose loose. Happens a lot.

Sure hate for it to be the turbo...you deserve a break after all you did! PLus, I would think a couple of other codes would pop if the turbo was going.

Ya, i feel like a turbo failure would have other symptoms.

Johnboy wrote:

I had the same code when the EGR went out. When it happened, I had 2 codes, EGR and turbo...Dealer replaced EGR and no CEL since.

We have been running the ORM for the past 3500 miles(at exactly 36000 miles now!), is it possible it still failed while while running the ORM? Or would the EGR not fail if it wasn't still active? EGR looks like a pita to get to, and is pricy enough that its not something to willing nilly replace to see if it fixes it.

Jeger wrote:

lets see...would that be P0299 or P0299

If nothing is obviously wrong, pull off the little filter for the boost control...right behind the air box..it that fixes it put a new one on. Maybe it got goofed up when it was rolled?

Scanner read 0299, but its not like Im trying to figure if its 0299 or 0299, im pretty sure its just 0299.

I remember the little filter you are talking about, but since I am troubleshooting the vehicle remotely I am just working off of memory, does anyone have a picture I can pass along to help him locate it?

I had him check the FCV out, said it appears to operate properly, opens and closes like it should, had him clean the MAP said ti was gunky, had him bleed out out of the filter head, checked boost hoses over but cannot see anything just obviously wrong. We are working to get him setup with a boost leak tester.

So my thinking on this filter is that perhaps its clogged or something so the turbo isnt able to actuate the vanes to produce boost?

Maybe its time for a FSM.

Cowpie1 · **Posted:** Tue Aug 14, 2007 9:58 pm

Recently got the P0299 when my vacuum line took a dump. Got the P1252 previous to that and my ABS, Traction control, and ESP lights all came on. The P1252 came on first all the time, then later the P0299 came up when I lost all turbo boost. All this was cured by a vacuum line.

Jeger · **Posted:** Wed Aug 15, 2007 8:00 am

The little filter is near the left fender behind the airbox...sorta under some stuff but easily seen if you look. It looks like a lawnmower sized clear plastic fuel filter and is plugged in hanging vertically on a piece of tubing with the open end in free air.

Sir Sam · **Posted:** Wed Aug 15, 2007 2:26 pm

Jeger wrote:

The little filter is near the left fender behind the airbox...sorta under some stuff but easily seen if you look. It looks like a lawnmower sized clear plastic fuel filter and is plugged in hanging vertically on a piece of tubing with the open end in free air.

Yes I remember, nothing seems wrong with it, not clogged or anything.

tigafila · **Posted:** Tue Aug 21, 2007 11:28 pm

Did you find the cause of the p0299? I just got one too. Tigafila

Sir Sam · **Posted:** Tue Aug 21, 2007 11:37 pm

tigafila wrote:

Did you find the cause of the p0299? I just got one too. Tigafila

Yes, CAC hose failure.

Does yours present with issues of very poor drivability and no power??

http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=23556

tigafila · **Posted:** Wed Aug 22, 2007 10:35 pm

I looked at the CAC hoses today and they looked & felt ok but I guess I'll have to take them out & check them. I thought I had it while doing a visual inspection today I found a large mouse nest in the airbox. It's better but still check engine light and lacking power. Thanks, Tigafila

Sir Sam · **Posted:** Thu Aug 23, 2007 12:40 am

tigafila wrote:

I looked at the CAC hoses today and they looked & felt ok but I guess I'll have to take them out & check them. I thought I had it while doing a visual inspection today I found a large mouse nest in the airbox. It's better but still check engine light and lacking power. Thanks, Tigafila

time for a boost pressure test, at least if you test it and find no leaks youll know the problem isnt with a boost leak.

So what do you guys make of P0299?

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