What Does P00AC Mean?
The PCM has detected that the intake air temperature sensor 1 circuit on bank 2 is reading below the minimum expected voltage threshold. For NTC thermistor sensors, this low voltage represents low resistance, which the PCM interprets as an implausibly high air temperature. This is typically a short-to-ground condition in the sensor or wiring. The engine may run slightly rich as the PCM compensates for what it believes is very hot intake air.
Common Causes
35%
Internally shorted intake air temperature sensor 1 on bank 2
30%
Signal wire shorted to ground from chafing or pinched wiring
20%
Water or corrosion in the sensor connector creating a low-resistance bridge
15%
PCM internal pull-down fault on the sensor input circuit
Diagnostic Steps
1
Check the IAT sensor 1 bank 2 PID with the engine cold — if it shows an extremely high temperature (250°F+) when it should be near ambient, a short-to-ground is confirmed.
2
Disconnect the sensor connector and observe the PID — if it jumps to -40°F, the short is in the sensor itself. If it stays high, the short is in the wiring.
3
Measure the sensor resistance (disconnected) — it should be 2–3 kΩ at room temperature. Near 0 Ω confirms an internally shorted sensor element.
4
With the sensor unplugged, measure resistance from the signal wire (harness side) to chassis ground — should be infinite. Low readings indicate a wiring short.
5
Trace the wiring harness and inspect for areas where insulation is damaged, particularly near sharp edges, brackets, or hot components.
Estimated Repair Cost
$40 - $200
Parts + labor, varies by vehicle and location
The PCM has detected that the intake air temperature sensor 1 circuit on bank 2 is reading below the minimum expected voltage threshold. For NTC thermistor sensors, this low voltage represents low resistance, which the PCM interprets as an implausibly high air temperature. This is typically a short-...
The most common cause of P00AC (Intake Air Temperature Sensor 1 Circuit Low Bank 2) is: Internally shorted intake air temperature sensor 1 on bank 2
Typical repair costs for P00AC range from $40 to $200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. The PCM will use a substitute value or may run slightly rich to compensate for the perceived high air temperature. Fuel economy will decrease. Repair when possible.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P00AC to identify the root cause.
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Quick Info
Category
Powertrain
System
Intake Air System
Difficulty
Type
Generic (SAE)
Recommended Tools
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