What Causes Car Jerking When the AC is Turned On?

1 Answers
LeSamantha
07/30/25 7:50am
Car jerking when the AC is turned on may be caused by severe carbon buildup in the engine cylinders. Fuel supply malfunction: Engine logic error: Unable to receive the AC activation signal. When the system cannot determine whether the AC is turned on, the Engine Control Unit (ECU) mistakenly interprets it as a temporary high load and attempts to compensate by increasing the RPM to offset idle resistance. When the engine RPM drops, it cannot handle the load from the AC compressor, causing the RPM to rise again. This back-and-forth results in unstable idling. AC control circuit malfunction: Unable to send the AC activation signal. Similar to the first scenario, since the system cannot determine the AC's operational status, the ECU continuously adjusts the idle RPM, leading to unstable idling.
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