Diagnose Engine Codes

bigcoupee · **Posted:** Sun Jun 15, 2008 8:49 pm

These are the engine codes its throwing, keep in mind i had the Mass Air Flow unplugged. I made the huge mistake of running my jeep through a mud pit, 8 hour job to pull the rad and intercooler to clean it, now it seems low on power and have bad turbo lag. Put a new airfilter and fuel filter in. Thx

102
1252
415
299

Sir Sam · **Posted:** Sun Jun 15, 2008 11:03 pm

bigcoupee wrote:

These are the engine codes its throwing, keep in mind i had the Mass Air Flow unplugged. I made the huge mistake of running my jeep through a mud pit, 8 hour job to pull the rad and intercooler to clean it, now it seems low on power and have bad turbo lag. Put a new airfilter and fuel filter in. Thx

102
1252
415
299

P0299 - and the symptoms you describe are a good indicator that you have a boost leak. check hoses and such.

tjkj2002 · **Posted:** Sun Jun 15, 2008 11:16 pm

Codes start with a P,C,B,or U?

OBDII codes......

P0102---MAF circuit low input
P0299---Turbo underboost
P0415---Secondary air injection system relay "B" control circuit
P1252---Vacuum reservoir control circuit high

Always fix the lowest # code first,most likely the lowest # code is the culprit for the rest of the codes(not always though).

Sir Sam · **Posted:** Sun Jun 15, 2008 11:20 pm

tjkj2002 wrote:

Codes start with a P,C,B,or U?

OBDII codes......

P0102---MAF circuit low input
P0299---Turbo underboost
P0415---Secondary air injection system relay "B" control circuit
P1252---Vacuum reservoir control circuit high

Always fix the lowest # code first,most likely the lowest # code is the culprit for the rest of the codes(not always though).

in this case the P0299 would be the lowest, the MAF will cause the P0102 so its a non-issue.

tjkj2002 · **Posted:** Mon Jun 16, 2008 8:10 am

Sir Sam wrote:

tjkj2002 wrote:

Codes start with a P,C,B,or U?

OBDII codes......

P0102---MAF circuit low input
P0299---Turbo underboost
P0415---Secondary air injection system relay "B" control circuit
P1252---Vacuum reservoir control circuit high

Always fix the lowest # code first,most likely the lowest # code is the culprit for the rest of the codes(not always though).

in this case the P0299 would be the lowest, the MAF will cause the P0102 so its a non-issue.

Well duh the MAF is causing P0102 :lol:

,though it is the lowest code and can cause some of the others.

BlackLibertyCRD · **Posted:** Mon Jun 16, 2008 11:23 pm

Many of us here run with the P0102 all the time and get no other codes because we the MAF unplugged. I got a code reader plugged in all the time to keep the light out and very happy for it.

Uffe · **Posted:** Tue Jun 17, 2008 4:08 am

Err, if you got a vacuum low and turbo underboost you've got a vacuum leak which causes your variable vanes to turn out of the exhaust gas and produces less boost.

Check them vacuum lines sir!

bigcoupee · **Posted:** Thu Jun 19, 2008 2:11 am

I've been searching hi and low for the vacuum leak. I really believe that must be the problem, the turbo makes decent boost above 3k rpm, but the turbo lag and exhaust noise on the hiway is terrible. Ill keep looking and keep you posted...

Sir Sam · **Posted:** Thu Jun 19, 2008 2:27 am

bigcoupee wrote:

I've been searching hi and low for the vacuum leak. I really believe that must be the problem, the turbo makes decent boost above 3k rpm, but the turbo lag and exhaust noise on the hiway is terrible. Ill keep looking and keep you posted...

buy or make a boost tester and check for boost leaks.

bigcoupee · **Posted:** Sun Aug 10, 2008 10:20 pm

well I cracked and let the stealership tackle it. Problem is fixed but my but is still a bit sore, bill was $1700. Vacuum pump wrecked and packed full of mud, this fried my pcm. Jeep is working nicely, except my every once and a while i need to do a full dismantle and cleaning of my starter, it continues to pack full of dirt. My bellhousing filled with mud. Thinking about sticking a garden house up in there to wash the mud out.

Uffe · **Posted:** Mon Aug 11, 2008 2:08 am

bigcoupee wrote:

well I cracked and let the stealership tackle it. Problem is fixed but my but is still a bit sore, bill was $1700. Vacuum pump wrecked and packed full of mud, this fried my pcm. Jeep is working nicely, except my every once and a while i need to do a full dismantle and cleaning of my starter, it continues to pack full of dirt. My bellhousing filled with mud. Thinking about sticking a garden house up in there to wash the mud out.

Well sweet jeebus! That's a nasty bill and really nasty to have a packed vacuum pump. How'd your braking feel like while it was still poofed? Hard to brake?? Eep.

And obviously I'm "filled with joy" to have guessed something right! :oops:

geordi · **Posted:** Mon Jan 25, 2010 1:09 am

bigcoupee wrote:

well I cracked and let the stealership tackle it. Problem is fixed but my but is still a bit sore, bill was $1700. Vacuum pump wrecked and packed full of mud, this fried my pcm. Jeep is working nicely, except my every once and a while i need to do a full dismantle and cleaning of my starter, it continues to pack full of dirt. My bellhousing filled with mud. Thinking about sticking a garden house up in there to wash the mud out.

YEOUCH.

How exactly did the stealer determine that a vacuum pump damaged your COMPUTER?

I'm not discounting that the pump was filled with mud as you say, but I thought the pump was located behind the engine's front cover. It should be difficult for anything to get in there...?

Diagnose Engine Codes

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