sham4455

Dear All,

Greetings.
its been a pain diagnosing the AC issue in my 07 es 350, and hence im here to find my luck.
Turn of events:
1. 7th of May 2024- on my way home at 3 pm noticed the Ac cooling fading- with the uncompressed air smell.
*Reached Home and noticed the condensor side ac radiator fan not spinning.
* Reconfimed it by tapping on that particular fan motor and it spins slowly.
2. 10th of May 2024- Replaced the Fan motor with a DENSO unit ( PN: 263500-6170 )
3. 11th of May 2024- On the way to work ac was blowing cold, life is good.
* On the way back home from work, few 15 kms down the road, the stops working again.
* Reached home in the 45C (113 F) with out AC and verified the Condensor side fan is not working again.
* By passed the fan control module as such both the radiator fans run with the turn of the ignition at full blast.
4. 15 May Life is good again been on a 1500 Kms Road trip, with the working perfectly fine
* Concluded that the issue is somewhat related to the fan control module? ( Replaced the fan control module and wiring brought back to how it was originally)

5. 28 May, the same issue ac stopped working,
* Noticed the fan not spinning again though the compressor is engaged ( like as if someting is telling the fan to shut off)
* now im fed up and bypassed the connection again making the radiator fans to run continuously.
6. 29 May, Same thing happens inspite of both the fans running perfectly fine.
Since then fast forward to till date , The AC blows chilled freezing cold in the mornings on my way to work, and stops working on the way back. and would start working only the next morning.( so wierd that the ac stops exactly 15 kms from work to home half way)

Note: The fans are still bypassed to run at full speeds all the time.
No error codes when the ac is working perfectly in the morning, how ever the Code B 1451 popps up when the ac is not working.
its hard to believe the compressor is faulty because the mornings and first 15 kms back home its works freezing cold.
the region where i reside the temperatures during the day is 110-115 hence its turning out to be a nightmare driving without AC.

And though the ac doesnt blow cold air, when i look at the compressor, the magnetic clutch is engaged and hence the compressor is spinning.

Looking forward to any clue or support in this regard.

the car has 310,000 Kms

Best Regards,
Sam

Clutchless

A search for that code on Toyota found the following:
This is almost always a bad amplifier, but on occasion, we find the wiring between the compressor and amplifier to be the issue. You need to check the continuity of the wire and the resistance of the ground at the amplifier.
You may need a shop to run more tests.
See this:
https://www.autocodes.com/b1451_toyota.html

sham4455

Thanks for taking the time to provide the above information. Im just wondering if a faulty AC amplifier would cause ac not to work only if the ambient temperature is high? i mean the ac works perfectly fine in the mornings. ( almost 1 hr. drive everyday).
is there any way i could test this amplifier?
I do have a bi directional scan tool, would it help in any way?

thanks

Clutchless

I don't know the answer to those questions. You may need to have a pro A/C repair place check it out before you waste money throwing random parts at it.
If you don't have a local independent shop you trust, use this database to find some, then cross check on Google & Yelp as some reviews are old. https://www.cartalk.com/mechanics-files

RoseLexus

I'm new to this forum and was looking for some AC confirmation for a ES350 2009. The sticker on the car for refrigerant says HFC134a 1.21lbs max and .99lbs min, oil ND-Oil 8. The 8 is for 8 ounces of PAG-46? I did some searches online and found four-seasons-capacity-guide.pdf. It has 16.60-18.87 ounces for R-134a and 4.60 +/-.51 for PAG-46? I expect the sticker on car is correct and appreciate if anyone can confirm the oil amount. I thought it would be a simple search but I'm not finding. Thanks!

Note - I'm putting in GPD Compressor (6512793). I just checked, per label, it has 3.4 ounces of oil which I'll double check.
Note2 - Upon further research, showing my amateur status, the ND-8 is type of oil (PAG) on car sticker. I don't know why the sticker does not include total oil amount? I looked up the Denso compressor (which I understand come with full oil for system (471-1619) has 4.4 ounces which would be aligned with amount I found on-line (4.6+/-.51). So I presume compressor I have has a little less (maybe in case some oil in parts not changed). I'll need to add 1-2 ounces per this additional research. I measured oil out of compressor and got less than 3.4 (maybe if I let drip for hours would get closer). Sharing this in case someone else having similar experience and glad for any feedback, thanks.

Clutchless

RoseLexus - this question should be a new thread. Also do you have the equipment and skills to evacute and charge the system yourself? These are not things the usual home mechanic has laying around.
You may want to consult with a professional automobile AC shop.
You may also want to search the Toyota Nation forum for the Camry of similar generation as those folks do a lot more work on their own vehicles and it is a mechanical twin.
https://www.toyotanation.com/forums/...lara-forum.15/