Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

2006 Scion TC A/C Help

More
6 years 6 months ago #13040 by joshuamal
Hello, on the below Youtube video by Paul, around min 3:25 started talking about the low pressure will cycle and the high will rise as the compressor engages and the clutch would spin, I have a Scion TC 2006 the low pressure it’s reading about 20-25, the high about 70, it doesn’t cycle or goes up but the clutch it's spining, I’m thinking the compressor is bad as it’s probably weak to make the pressure rise. I also noticed the RPM change when the AC it’s turn on as describe at the beginning of video. So, all this would mean everything is fine and I would need a compressor, What do all you think ?




please help

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13049 by Andy.MacFadyen
What is the pressure engine off engine stone cold ? With R134a the pressure measured in PSI on either port should be roughly the same number as the temperature in degrees Farenheit.

" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)



Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13064 by joshuamal
Replied by joshuamal on topic 2006 Scion TC A/C Help
the pressures at rest engine not running are about 90 on both, then AC on 20 low side & 70 high side, the clutch engages, it has a small system capacity of about 16 oz so it has probably 14 oz in it. the evaporator, expansion valve, condenser was replaced this weekend but when filling Freon it's about those pressures.
Attachments:

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13078 by ScannerDanner
Thanks for posting this here. We talked a little on YouTube about this.
90 psi of rest psi, then a low , low side and a low, high side pressure. This is an odd symptom. It could be the compressor. What is the history of this. Why were all those other AC parts replaced? When did this problem start?
Are you 100% sure on that charge capacity? I could check too

Don't be a parts changer!

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13147 by joshuamal
Replied by joshuamal on topic 2006 Scion TC A/C Help
Hello Paul,
Thanks for taking time to read my concern here and on youtube. These parts were change because the evaporator was leaking so the evaporator and expansion valve I replaced them, as I was trying to charge noticed the condenser had stains of leaking dye so I went ahead and replaced it. After chatting with you on youtube went home and took the charge at rest and both were the same about 90 PSI but this was at night with an approximate temp of 75 or so. After that I turned the AC on and it was close to 20 on low side and about 70 high side, neither of the pressures would cycle or rise back and forth. I tried taking a video and post it here but didn't go through.

I did check things electrically as shown on your video for the Odessy and the AC clutch was engage. I noticed the RPM changed when turning the AC on as you described on video, knowing the clutch was engage it means the compressor it's getting power, well at least in my understanding; checked the relays for power and ground. I noticed something and perhaps if you can explain this to me will greatly appreciate it so I can learn: on the relays you mentioned there must be two powers and two grounds for the control and load side, well I found this as the key must be on to check powers at relay, without the relay, the load side there was power and ground, the control side there were powers on both, had my test light on ground and show power on both but on one when it showed power on my test light the fan came on, I guess that relay also controls the fan.
can you help me on this or guide me? Maybe if you can post a copy of the diagram here so I can understand with your explanation.

For what I found out it's a low capacity system, about 16oz is what Toyota told me and Orilleys 15oz, please help me out on this capacity as well if possible, there is no label on vehicle.

By the way Paul you are a great teacher wish I was near you, I have learned quite a bit from you and trying to learn more from you, I watch at least two videos every day.
One thing if possible can you make more videos with basic tools instead of the fancy ones, I don't have scanners and scope but want to learn as much as possible. Lol .

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13236 by Chad
Replied by Chad on topic 2006 Scion TC A/C Help
If the clutch is engaging, chances are that everything electrical is ok. I have seen weird pressures similar to that before. A car came in from another shop. They had installed a used compressor . The little red shipping plug was STILL in the compressor!

Are you sure you have removed all shipping plugs? No restrictions?

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago - 6 years 6 months ago #13237 by Andy.MacFadyen

pole71 wrote: If the clutch is engaging, chances are that everything electrical is ok. I have seen weird pressures similar to that before. A car came in from another shop. They had installed a used compressor . The little red shipping plug was STILL in the compressor!

Are you sure you have removed all shipping plugs? No restrictions?



I have been thinking about this over the last few days and that is only idea so far that i makes sense, a blockage in the high pressure side after the compressor outlet but before the high pressure test port.
It explains why the running pressures don't make sense compared the rest pressures. With the system running a lot of refrigerant must be trapped at very high pressure after the compressor but before the HP test port.

" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)



Last edit: 6 years 6 months ago by Andy.MacFadyen.

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13238 by joshuamal
Replied by joshuamal on topic 2006 Scion TC A/C Help
Hello Pole,
Well I'm completely lost now and not sure what directions to take, the pressures I had listed were with the old compressor, today I installed the new one and now can't get the clutch to engage with AC on, I did jumped the load side of relay and it work, I have power on it all fuses good I even swap the relay and nothing, I checked the control side and I have power on both terminals so had my test light to ground and the fans came on as it's run by the control side of relay.
Not sure which way to go now

Any help will be great

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13239 by joshuamal
Replied by joshuamal on topic 2006 Scion TC A/C Help
Hi, those readings were with the old compressor I just installed the new one today and now the clutch doesn't come on but I'm able to jump the relay and engages, control side works the fans as well and these work fine.
Not sure where to go now

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13240 by Chad
Replied by Chad on topic 2006 Scion TC A/C Help
Hopefully, these will help with the clutch engagement.

As for trying to find a restriction, there will be a temperature change where there is a pressure drop. 70 psi down to 20 psi is not HUGE, but should still create a temperature change. Can you FEEL a place in the lines, other than before and after the TXV, that the temperature changes for no apparent reason?

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)
Attachments:
The following user(s) said Thank You: Tyler

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13277 by joshuamal
Replied by joshuamal on topic 2006 Scion TC A/C Help
I have checked here at the AC relay and seems to be fine, as I jumped the load side the clutch kicks on, when I checked the control side my fans come on, I'm not sure which direction to go to now, I have power on both sides of relay , one thing I noticed now is, when I turned AC on there is no change in rpm and compressor clutch doesn't come on

Any ideas ? Please advise I'm completely lost now

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13280 by cheryl hartkorn
any scan data you can use?? did the evap temp sensor get plugged back in when the evaporator was replaced?? if i understand right you can jump the relay and the a.c. works?? is it cold going down the road with it jumped?? and you said you had power on 1 side of the coil. so that means the relay isnt getting grounded.

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago - 6 years 6 months ago #13281 by Chad
Replied by Chad on topic 2006 Scion TC A/C Help
Have you checked the relay, itself?
If the command for AC Clutch is present, the GRN (2) wire at the Relay will show a ground with the relay removed. If it does, all inputs and ecm are fine. The problem lies at the relay, or after.
Back probing the BRN(2) (which becomes the GRN) wire at the ECM to ground, with the relay installed should kick on the clutch AND fans. If it does, you have an input or .ECM problem

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)
Attachments:
Last edit: 6 years 6 months ago by Chad.

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13282 by joshuamal
Replied by joshuamal on topic 2006 Scion TC A/C Help
Cheryl, at this time I don't have a scan tool until mid this week, all sensors are plugged in, i was able to jump the load side and the clutch came on as it has power, the control side I have power on both and fans come on as the control side controls the fans, I have no freon on it yet as the clutch would not engage, just replaced it and when o was going to charge it I noticed the clutch would not engage. If is getting the fans on it means the relay is being grounded, I have checked all fuses and all are fine, swapped the relay with another one and didn't do anything either, that's where I am.

Any other ideas?

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago - 6 years 6 months ago #13283 by Chad
Replied by Chad on topic 2006 Scion TC A/C Help

joshuamal wrote: I have no freon on it yet as the clutch would not engage

You have to start charging to increase the internal pressure before the clutch will kick in. :whistle:

Low pressure cut out.

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)
Last edit: 6 years 6 months ago by Chad.

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13284 by Chad
Replied by Chad on topic 2006 Scion TC A/C Help
You should also connect a vacuum pump and start the charging from a vacuum. The vacuum makes any moisture/humidity boil off. Moisture in the system is not good.

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13285 by joshuamal
Replied by joshuamal on topic 2006 Scion TC A/C Help
If I can't get it to engage, how is it going to suck the freon as I'm manually charging without a machine? before when I replaced the evaporator the compressor engaged when I turned it on to charge the system but now it's not doing anything at all, I can jump it at relay and it cuts on and the fans work.

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13286 by Chad
Replied by Chad on topic 2006 Scion TC A/C Help

joshuamal wrote: If I can't get it to engage, how is it going to suck the freon .


It doesn't "suck" the freon in. The pressure inside the can is higher than atmospheric pressure. When you open up the pressure of the can to the (should be vacuumed down) lower pressure of the system, the pressure FORCES the freon into the system. The pressure inside the system will start to rise. The pressure will continue to rise until it equals the pressure inside the can, or freon runs out. If the pressure inside the system becomes equal the pressure in the can (70 psi? I'm not sure of the can pressure), no freon exchange takes place. This, or slightly before this, is where you would know you have and engagement problem. The pressure sensor will detect this pressure and say "OK, I have some freon. Start the compressor". When the compressor kicks on, the low side pressure is THEN pulled down to about 20 - 40 psi. while the high side continues to build more pressure.

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago - 6 years 6 months ago #13288 by Chad
Replied by Chad on topic 2006 Scion TC A/C Help
If the low side pressure gets pulled down TOO much (because the compressor is stuffing all the freon over to the high side), say below 20-25 psi, the pressure sensor will detect this too. The compressor cuts out due to the lack of pressure/freon. After the compressor stops, pressure from the high side bleeds over to the low side via the TXV, or orifice tube. Pressure on the high side falls, Low side rises. Pressure sensor sees pressure on the low side, again, turns compressor on. This is what happens when you hear a clutch kicking on and off ,excessively. It's a sign of low freon.

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

I have learned more by being wrong, than I have by being right. :-)
Last edit: 6 years 6 months ago by Chad.

Please Log in or Create an account to join the conversation.

More
6 years 6 months ago #13298 by cheryl hartkorn
so im confused here. you dont have any freon in the system with the new compressor?? your trying to charge it up?

Please Log in or Create an account to join the conversation.

Time to create page: 0.277 seconds