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Chrysler Repair/'91 3.3/3.8L: egr/throttle body, fan relay; codes 21,35, 52


QUESTION: Hi Roland, we talked about a sticky EGR valve on my New Yorker, The codes I gave you were 12  21 32 52 55
I was wrong, the 32 (ERG)   was actually 35.
So 12 was corrected , I think 21 and 52 go together, the oxygen sensor and 52 was fan relay something?
Question is the Oxygen Sensor, should that be replaced? I say YES, and the Fan Relay , is that something that needs to be fixed? Also you mentioned the EGR might not show on code, so I am having it cleaned just the same.       SO my questions are about the Oxygen Sensor and code 35 ?

Also what about throttle.Should that be cleaned?


ANSWER: Hi Jennifer,
Yes the 35 is for the fan control circuit is concerned you would notice that if when the temp gauge got to 3/4 or more (or simply request AC which also turns on the fans) the fans didn't come on. There is a fuse in the power distribution box under the hood that is 30 amp size and should be labeled. Check that first. Next would be the radiator fan relay which is also in that box which you could switch out with another relay in the box with the same part number (but is not essential to engine operation) and then see if the fans work. If still not, then the wiring to the fans may be at fault.
The oxygen sensor as I said earlier would improve the mileage and decrease the pollution if it was working, and if you have a vehicle inspection requirement where you live that would be 'caught' and have to be fixed at that time. So you might as well do it if that is the case.
On the egr, because there is no code that would mean the electrical part of it is working, so again I believe that only putting WD-40 on the stem and moving it back and forth will solve that problem. Try that first before having someone remove the valve entirely as that would be less expensive (no expense, really) and would avoid possible damage from taking it out entirely to clean the interior. Cleaning the throat and plate of the throttle body is a good idea and that shouldn't take more than 15 minutes of shop time.
So if all this is being done at the shop just do the WD-40 lub on the egr, clean the throttle body, and check the fan fuse, relay, and if necessary wiring. This is not a major labor job so if they want to charge you for more than an hour of labor I would go elsewhere to get the job done.
Thanks for the ratings/nominations of which jsut one more will be the limit that counts, 5.

---------- FOLLOW-UP ----------

QUESTION: Okay, I am a tiny bit car doesnt have to do the emissions test, I think that is where the Oxygen Sensor would come into play? The garage said it did not need to be replaced now?  So that confuses me, I thought if a code came up, that meant the part that relates to the code should be fixed?   Also they werent concerned with the code 35, the radiator fan relay is what I believe they called it.....I never overheat and the gauge doesnt even go up the slightest, so I am not sure why they were not concerned with that?      This is my garage, they have always treated me fairly and I have used them for 10 years now, on a few different vehicles.   I know there are a lot of questions in this ,  The throttle body comes out to clean , its not just a spray job , like the EGR?     So I would ask them to lube the EGR valve, make sure the stem goes back and forth and clean the throttle body.For some reason they did not seem concerned with code 35, which they called radiator fan relay. Last thing is, how come me and you never thought of throttle before?

ANSWER: Hi Jennifer,
On the oxygen sensor, if there is no inspection then replacing it would only help your fuel economy a bit and reduce the air pollution coming out the tailpipe. If the garage doesn't recommend replacing it (due to cost I presume) then you have an honest garage, but I can't tell you how much fuel saving/pollution reduction you will experience by investing in that replacement.
If the temp gauge isn't going up at all, then my only question would be do the fans perhaps run all the time instead of never? If so, then possibly the fan relay is stuck 'on', which means the engine will run cooler than necessary, which also reduces the fuel economy. So run the engine and see whether the fans are 'on' all the time or never. A relay, if that were the cause, is just the charge for the part (no more than $25).
The throttle body clean out is done by just removing the air cleaner housing and wiping off the throat and plate of it, no other 'removal' is involved and it is a quick job. There is no code for that, and the symptom that you described originally (hesitation) is not likely to be caused by a dirty throttle body. If that were very dirty you might have poor running at idle and at low speed acceleration rather than hesitation at high speed acceleration. It is always a good idea to look at the throttle body cleanliness nonetheless, but no code is usually due to that.

---------- FOLLOW-UP ----------

QUESTION: Hi, its me again, lol....Okay so cleaning the throttle is an easy job and it never hurts to clean a dirty part, kinda like that? And the fan, if I start the car, I assume the fan is under the hood......should the fan be running or not running? How would I check to see if they are "on" all the time?

Correct about the throttle body. The fans should only come on when the temp gauge pushes above half to three-quarter scale EXCEPT if you ask for air conditioning the fans run whether or not the gauges reads above half to three-quarters, e.g it will run all the time if you have selected the AC to run. You can either open the hood and look at them, or listen for the sound of the fans which are often auditable from the cabin.

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Roland Finston


Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

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I have do-it-yourself experience (50+ years) and a library of 100 1982-2012 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.

I was voted "Top Expert" 2010-2015, here at AllExperts, and have answered 20,000+ questions.


Five decades as a 'do-it-yourselfer' on domestic and imported cars.

Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)

Advanced degrees in Physics/bruised knuckles

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"Top expert" of 2010, 2011, 2012, 2013, 2014 and 2015 here at Allexperts. Quickest "average response time" at Allexperts (currently no. 1).

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