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77K views 229 replies 13 participants last post by  TaxiGirl 
#1 ·
Hello. I just stopped by dealer because i could not find a part number for the ac relay. Turns out there is no part number but, there is a spare relay in fuse box. If that one does not work then maybe the TPIM which i had replaced last July.
Does anyone have any idea how i determine the problem?
What is the low side psi and the higjside psi supposed to be?
 
#2 ·
PSI will depend on ambient temperature.
With the A/C getting hot at idle and cool at speed, it's probably not the relay. I'd bet on either a refrigerant charge issue or the cooling fans not pulling enough air (though I'd suspect the engine would get warm at idle in that case).
 
#6 ·
This chart shows the expected pressures at given temperatures.
33aylu8.jpg
Relay voltage should roughly be battery (+) voltage with the engine running and A/C on.
If it is cooling OK while you are driving, but blowing warm when you are stopped at an idle, then it doesn't sound to me like a TIPM or relay problem.
Do the radiator electric fans come on and run when the A/C is on and the vehicle parked? If air isn't moving through the condenser in front of the radiator, then it won't blow cold air in the vehicle. Heat needs to be removed from the condenser by the fans running or air blowing through the grille at highway speeds.
While you are driving, plenty of air is blowing through the condenser and it is able to cool the interior.
If the electric fans are not running, then the hi-side pressure will skyrocket and you may have already lost some of the charge out the hi-pressure relief valve. You will need to add charge after the fans are fixed.
At 98°F, I would expect a hi-side pressure of 280-300 psi with the fans on according to the above chart.
 
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#7 ·
This chart shows the expected pressures at given temperatures.
33aylu8.jpg
Relay voltage should roughly be battery (+) voltage with the engine running and A/C on.
If it is cooling OK while you are driving, but blowing warm when you are stopped at an idle, then it doesn't sound to me like a TIPM or relay problem.
Do the radiator electric fans come on and run when the A/C is on and the vehicle parked? If air isn't moving through the condenser in front of the radiator, then it won't blow cold air in the vehicle. Heat needs to be removed from the condenser by the fans running or air blowing through the grille at highway speeds.
While you are driving, plenty of air is blowing through the condenser and it is able to cool the interior.
If the electric fans are not running, then the hi-side pressure will skyrocket and you may have already lost some of the charge out the hi-pressure relief valve. You will need to add charge after the fans are fixed.
At 98°F, I would expect a hi-side pressure of 280-300 psi with the fans on according to the above chart.
HI, thank you. Yes fan is running when it is supposed to run.

Are there high and low psi switches?
 
#8 ·
There is a pressure transducer that tells the PCM the high-side pressure. The PCM uses this information to shut-down the A/C if the pressure is too high or too low. It will cycle the fans on or off depending on high-side pressure in normal operation.
An evaporator temperature sensor will tell the PCM the evap temp. It will use this information to cycle the compressor to keep the evap as cold as possible without danger of freezing. About 36°F.
 
#9 ·
There is a pressure transducer that tells the PCM the high-side pressure. The PCM uses this information to shut-down the A/C if the pressure is too high or too low. It will cycle the fans on or off depending on high-side pressure in normal operation.
An evaporator temperature sensor will tell the PCM the evap temp. It will use this information to cycle the compressor to keep the evap as cold as possible without danger of freezing. About 36°F.
Thank you for that, but are they accessible? Can i test them?
 
#10 ·
They are both easily watched with a good scan tool. The transducer pressure should closely match the hi-side gauge pressure.
The evap temp is best seen with a scan tool. If you can see the evaporator fins from under the dash, they should be wet with condensate, but not white with frost.
The transducer and sensor probe may or may not set a fault code.
 
#12 ·
In the title to this post "blows cold when moving hot when idle" This almost sounds like an air flow issue. What is the condition of the condenser possibly clogged with dirt and other debris?
 
#13 · (Edited)
How would i know the condition of the condensor?

I am at a shop now and yesterday when i had it looked at the guy put in .38 lbs of freon and before i got out of the parking lot, it was blowing hot in the front and the rear a/c was still working. Today i went to a different mechanic shop and they said there was 2.83 lbs of freon and it was overcharged and they recovered that and i was charged $110. So, i am getting ready to leave and I notice that the rear ac is not coming on. So, now I am paying them $54 just to take the rear a/c panel off to check to see if power is getting to the blower. If power is not being supplied to the blower the only other thing i can think of is it is not being told to come on from the pcm. Or the switches in the front are not working. The sync light is coming on but nothing i do is turning on the rear a/c. Although the rear a/c worked yesterday.

WELL. There is no power being supplied to the rear a/c blower
 
#16 ·
It has been a while since I've actually played with the HVAC controls in a van...

I believe you can have the system synced while still having the rear A/C off (Sync should only sync the temp of the front two zones, unless you also have the rear set to front control and auto temp). You need to verify that you have the rear A/C control panel locked, so that it can only be controlled by the main (front) controller and you need to verify that the rear is not off. You should see "REAR AUTO" in the middle of the temperature display. (If you have a 2011, look at page 333 of your owner's manual and read from there.)

If you're unsure of this, simply poke your head in the back and turn the rear controls to their maximum cooling settings.

Once you have verified that the settings are correct on the controls, and the rear motor is still not working, we can look at the next step:

The next thing to check is to turn the rear fan speed to it's highest setting (use both sets of controls if you're uncertain of which one is actually controlling the system). If the fan suddenly starts working, but works only on the high setting, then the rear blower motor resistor has failed. If the fan does not work at all on any speed setting, this is not your issue.

If the controls are set correctly and the rear fan is not working, then the issue gets harder to diagnose. There is no fuse for the rear blower motor. You could have poor connection, a failed motor, a cut wire, a bad relay, a bad control unit, or some other gremlin, and will require tools such as a multimeter, at minimum, to go much further with. If you're handy with a wrench and have tools, we can go a bit further. If not, I'd suggest taking it to a dealer for diagnosis.
 
#17 ·
Thank You Jerry. I have been trying to respond to your post but, Microsoft has almost rendered my laptop useless, like they have with everyone that I have ever have had before.
The blower motor was not getting the power with the settings set correctly and since it feels like it is 150 degrees outside, I just took it to the dealer. I have a bad feeling about the whole thing because the day that I took it to the dealer I had some other unexplained surges in the power and at one point the temps on my radiator and oil surged to 235 degrees. I stopped got out and everything seemed to be fine. I also noticed that my less than a year old Sears Diehard battery seemed to be bulging little at the top. These are signs to me that the TIPM IS GOING OUT AGAIN.
 
#18 ·
If the battery is bulging I would have it checked ASAP. That is NOT a good sign. The battery is being overcharged. The swelling is the build up of hydrogen gas and it could very well explode. Personally, I would not drive it until a proper diagnosis is completed.

Sounds like a good diagnostic check needs to be performed. I'm not discounting the TIPM being bad, but I would want to rule out all other possibilities before replacing the TIPM. They are very pricey.
 
#19 ·
It could also swell from excessive heat, but I would definitely have the charging system checked. More than likely the voltage regulator (which is in the TIPM?) is faulty. Again - it could be the excessive heat causing it to not regulate properly. Either way it should be checked.
 
#20 ·
Underhood heat during taxi-duty can get pretty high with prolonged idling and A/C use.
The factory battery is wrapped with a Thermoguard® cover.
Many times after a battery replacement, this cover is forgotten and not reinstalled. It is more important than it looks. Make sure that it is in place.
Dodge Grand Caravan C/V. #05235267AD: COVER. Battery. Thermoguard.
 
#21 ·
Underhood heat during taxi-duty can get pretty high with prolonged idling and A/C use.
The factory battery is wrapped with a Thermoguard® cover.
Many times after a battery replacement, this cover is forgotten and not reinstalled. It is more important than it looks. Make sure that it is in place.
Dodge Grand Caravan C/V. #05235267AD: COVER. Battery. Thermoguard.
Battery has been replaced several times. In 2015 i had to replace it and the alternator 2 times due to the TIPM overcharging the battery to 18 v. I thought that the dealership installed a new TIPM but, they probably gave me some refurbed piece of crap. The warranty on part would be out in July for the year but they have the 12k miles as part of the warrenty so it will not apply. It cost me 1205.00 last year. And if i have to replace it again, Dodge is going to hear about it. I am sick of having to replace good parts gobe bad becsuse of their defective TIPMs
 
#26 ·
Are you sure they gave you info on YOUR van? The only thing I can find that talks about a wireless control module is for the ignition system. Given the CEL now being on and the PCV issue, I wonder if they're not confused and accidentally telling you about someone else's van?
 
#29 ·
Ok, he called,back said it is the HVAC module will charge $652. (P&L) I think i could do it myself. He said code was number 4 misfire but i jave plugs at home. If i can replace the hvac module myself, the warranty is worthless for in in a taxi to have them do it.
The part number is 55111367AE
 
#32 ·
Taxi; I have a 2006 PT with the TIPM system. Likely similar to yours. The alternator is controlled by the engine computer, not the TIPM. I've heard about [but never saw] a voltmeter that plugs into your cigar lighter. You could make your own with a plug-in jack and a cheap VOM [volt ohm meter] and some tape. 18 v is waaay high.
 
#35 ·
I have a voltmeter. I have lots of tools. All i know is last July my battery was being charged to 18 volts. And it was bulging. Eventually i had to tow it to Dealership. I raised hell about my battery being charged to 18 volts and how it would not even run anymore. They replaced the TIPM and that fixed the problem.
 
#33 ·
A decent multimeter can be found at any auto parts retailer for under $30.

You can try cleaning the EGR, but if that doesn't cure the P0404 code then you'll probably need to replace it. You can try to check the wiring for damage and check the voltage if you have a multimeter.

P0404 Exhaust Gas Recirculation Circuit Range/Performance - DTC Code
 
#41 ·
A decent multimeter can be found at any auto parts retailer for under $30.

You can try cleaning the EGR, but if that doesn't cure the P0404 code then you'll probably need to replace it. You can try to check the wiring for damage and check the voltage if you have a multimeter.

P0404 Exhaust Gas Recirculation Circuit Range/Performance - DTC Code
I cannot locate a EGR on my van nor can I find any information that supports that it has one online or in parts order sites.
 
#34 ·
Number 4 cylinder misfire that you mentioned in post #29 would be a fault code P0304. Is that the correct code and not the P0404?
The Pentastar head extended warranty may cover this misfire if it is a valve problem and if this is the Pentastar engine.
 
#36 ·
Hi, yes i have already had the head replaced under that 150k warranty. And it looks like it may be already messing up again..Yesterday he told me po404. I hope it is 404. I will find out today. They cannot fix the a/c until Tuesday so I am going up there to pick it up so i can do some of the other work that needs to be done. I will just take it back there before they open on Tuesday.
 
#38 ·
I do not have a diagram for you, but the PCV valve is located on the left bank (of the engine), which is the bank closest towards the rear of the van. It will have tube that is about 3/4" in diameter hooked up to it and it will be held on with 2 or 3 screws. Remove it, then clean it by spraying either brake cleaner or carb/intake cleaner through it to remove all deposits. Shake the valve to ensure that the ball inside it moves freely - you should hear it rattle.

Said another way, the PCV valve should be on the transmission end of the engine, on the cylinder bank under the firewall. You'll be working between the intake and the battery...

After a bit more research, it seems the 3.6L may NOT have an EGR valve that is serviceable, given the design of the heads... Since you were told the van has a misfire, until you can confirm the actual issue (code P0304 or code P0404), I wouldn't worry about doing anything with that part of the engine.

Also, if you have plugs and you plan on doing them soon, removing the intake (which you'll need to do to change plugs) might make cleaning the PCV valve easier. Perhaps you could do them at the same time?
 
#39 ·
I got van back on Friday because Clay Cooley could not get my part in time and they were going to hold it hostage until today. I knew the check engine was not on so I took the van replaced the plugs and #4 coil pack also I may have cleaned the PCV although I am not sure because I do not exactly know where it is. If you are referring to this thing as being the pcv then what I did was remove the hoses to it, sprayed in some map sensor cleaner and I did that to the vacuum pump and hoses from breather to intake. Then it would not start. Then I got starting fluid and did the same thing, put the fan on it went to sleep and got up and it started.
I do not understand why this dealership will not give me a print of the result from the $140 diagnostic test that I paid for. I think possibly because they do not want me to fix it, job security or it really never had the codes. It is probably both. So far they charged me $603. This would be for the HVAC module, environment recovery, diagnostics and I will have to pay the labor to install the HVAC module which takes all of 5 min another $255
I have purchased so many parts at this dealership. They are not treating me right. They are the closest dealer to me. So, I took it back there at 7:30 am this morning. Still no word. I rented a car for a week $500 cannot make any money and they are dragging this out. Very irritating. I uploaded a pic of what I think could be the pcv

Attached Files:
 

Attachments

#44 ·
If this is the 3.6L Pentastar engine, they don't have an EGR valve.
These engines have VVT (variable valve timing) and by varying the amount of time or camshaft angle that both valves are held open between the exhaust and intake strokes, they can vary the amount of exhaust gases left behind in the cylinder for the next cycle.
It is an intrinsic method for EGR.
Installing a larger or smaller battery than stock will mean that another way of insulating the battery will have to be found.
 
#45 ·
If this is the 3.6L Pentastar engine, they don't have an EGR valve.
These engines have VVT (variable valve timing) and by varying the amount of time or camshaft angle that both valves are held open between the exhaust and intake strokes, they can vary the amount of exhaust gases left behind in the cylinder for the next cycle.
It is an intrinsic method for EGR.
Installing a larger or smaller battery than stock will mean that another way of insulating the battery will have to be found.
Wow, a light bulb just came on. Before I had thought that my transmission was ,CVT but it was the VVT of the engine that i had this confused with. It does have a PCV though correct made up of some hose and a valve? This thing?
 

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#46 ·
That is the PCV.
There is a video here on changing one on a Challenger. Similar, but the Challenger engine is front-to-back and yours is sideways right-to-left.
The video says they are allen head screws, but they are really Torx head screws. Replacing the hose is also important. That is why it is sold with the valve.
 
#48 ·
That is the PCV.
There is a video here on changing one on a Challenger. Similar, but the Challenger engine is front-to-back and yours is sideways right-to-left.
The video says they are allen head screws, but they are really Torx head screws. Replacing the hose is also important. That is why it is sold with the valve.
Thank you. I would not have thought of cleaning it with mineral spirits. This is the one that I did spray clean but I did not remove it, I will do that now that I know what I need. Thanks for the link.
 
#50 ·
Did I miss it? I have NOT seen the OP state the year/make/model of their vehicle or the engine and transmission it is equipped with.

The battery and its thermal guard? Heat will kill a battery, and the crammed engine compartment of the newer vehicles and taxi service is probably heating the battery something awful. If the vehicle came with a thermal guard for the battery, you need it, if its lost or you retro-fitted a larger battery that won't fit the thermal guard, they make universal ones, you might have to search and order it online, but its worth it, you might find your battery lasts longer and you have less electrical problems with the thermal guard for the battery.

The owners manual should identify the PCV for you, perhaps NOT all do. If you tell us the year/make/model/engine/trans we could look up a picture for you by googling it.

There are very engines that do NOT have PCV valves, but many engines do NOT have EGR valves. If you've got a code for the EGR its a good chance you do have an EGR.

Most PCV's are a plastic bodied valve controlling flow through tubes ending at one of the valve covers and going to the intake manifold or throttle body. Some have the plastic or metal body screwed into the valve cover or intake manifold or throttle body with the tube going to the other end. You remove the PCV and clean it with typical carb/throttle body cleaner.

Some EGR valves are located in a spot that is very difficult to access, a few may be "uncleanable" in the sense you just can't get inside the portion with the valve and clean it.

It does seem like your Dealer is charging an awful lot for very little in return. If you are NOT negotiating a firm set tasks for them to do and what they will charge for it, this can happen. I would consider the time to go to the next dealer or if its isn't under warranty, shopping some local independent shops.

So far they have only given you OBDII codes, there are lots of other extended (proprietary codes) also, like codes for the HVAC that only the dealer tools or other very expensive tools can read for you. But for the codes he has given you, the OBDII codes, you can easily read those yourself. I think 2014 and later FCA vehicle will no longer spit out the OBDII codes in the odometer doing the key dance. If you're van is older than that, you can search youtube for the Chrysler or Dodge Key Dance and see a video on how to turn the key in a way to make the OBDII codes read on the odometer. You can find cheap OBDII readers for as little as $25 now a days. Again the key dance and obdII readers will only read out the OBDII codes and perhaps a few extra's FCA throws in. That will be most of the engine codes and any additional thing, like fans, the PCM (engine controller) controls, perhaps a few transmission codes, that come up with the key dance and OBDII readers. Other codes for HVAC modules or body computers, ABS, etc likely won't come up without using Dealer tools or some expensive 3rd Party tools.
 
#53 ·
The dealer told you that the PCV was clogged (which I doubt also) back in post #22.
Have them save all the old parts for you. Can they show you your bad part?
If it can be determined that the PCV is OK, you may be able to take this up with the Service Manager and get an 'adjustment'.
Better to meet with the Service Manager in person in their office. The Service Advisor may have to be present to get an idea of how this unfolded. Estimates and OKs should be written on the back of the repair order hard copy with the date/time/amount of what you OK'd.
They have to get back to addressing only the issues of what you brought the van in for.
 
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