Skip the auto shop - Our mechanics make house calls

Q: The TPS error code P0123 appears only when the AC is on

asked by on

I had the throttle position sensor replaced on the truck along with the connections and cables, because I was getting an error code P0123. The code indicates the throttle position sensor circuit high voltage. The code was cleared. However, each time I turn the AC on, this happens again. There is a low charge in the AC system, but no error codes appear. The AC compressor is working properly. When I drive the car without AC on, there is nothing out of the ordinary. Why does this code appear with the AC on?

Hello. The low charge in the A/C system is going to cause the A/C compressor to work harder than it should. This will put a greater load on the engine and may cause your throttle position sensor to give a bad reading. Have a certified technician set the A/C system to the proper levels and see if the P0123 code continues. Having the throttle body cleaned may also help fix this problem. If you need help with this, a certified technician from YourMechanic can come to your car’s location to diagnose the code more thoroughly in order to have this corrected.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Truck cranks but will not start

Of course, check to see if any diagnostic trouble codes have been recorded by the PCM. Check fuel adequacy and pressure (note, "old" fuel can result in no start) and check for function of fuel injectors. If you suspect inadequate...

Q: I have a Code P0601 on the PCM. I replaced the PCM, and now I have a code P0118, code P0123, and code P0193.

Hi there, the short answer to your question is no . A PCM with a P0601 (which is a memory module error in the PCM) cannot reliably retrieve codes for the codes you list (P0118 - coolant temp sensor, P0123...

Q: Car maintainence

Hi, thanks for writing in. You will need to have a mechanic scan the computer to see what codes are stored and pressure test the oil pressure to see if it is a sensor or internal engine problem. The tire...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...