SureTrack Community Fix: Go With the Flow, Again

Real Fixes from the SureTrack® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is currently available free with the purchase of a current Snap-on® diagnostic software version.

When you have a repeat issue, your first thought doesn’t always go to the components you replaced. But you should always factor in that some new parts may not work properly. SureTrack community member wagshop1 had a Toyota Camry in their shop that came in with the air conditioning working intermittently. They repaired it and returned the vehicle to the customer but it came back two days later with the same problem. They posed the question to the community, and with the help of fellow community member Richard_C and others, they were able to resolve the issue quickly.

The following Community Fix summarizes the interaction between members of the community that led to the solution.

2012 Toyota Camry LE 2.5L

A/C works intermittently, replaced flow sensor

Customer complains that air conditioning stops working.

Diagnostic Steps Performed/Parts Replaced
Confirmed that A/C works, but then goes from cold to hot out of vents intermittently. When the issue happens, cooling fans turn off and on. Almost as if compressor is turning on and off. Scanned computer for A/C codes. Found B1479 – flow sensor circuit, in history codes. Replaced flow sensor on compressor. Worked for 2 days, then same symptoms returned. Rescanned and same codes returned. Monitored PID’s on scan tool and found that regulator pressure sensor (MPaG) fluctuated between 1.9852 and 3.0533 and regulator control current (A) fluctuates from 0.000 to 0..751 when symptoms are occurring. When A/C is working, both those PID’s are steady at 3.0533 and 0.751. When the control current is fluctuating and reading 0.000, it seems compressor is shutting off. Is this a refrigerant low issue, compressor issue or an A/C amplifier issue.

Best Answer from Community Member Richard_C
I am guessing you got another bad flow sensor or have bad compressor. The amplifier just serves as an A/C control module and reads in data from the various sensors and components. Looks like it is seeing that data and shutting things down due to low flow.

Replaced flow sensor again and this confirmed that first replacement was defective.

Replace flow sensor, test drove vehicle and air conditioning worked consistently. Returned vehicle to customer and they have no longer have had any problems.

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.