P00AA
Intake Air Temperature Sensor 1 Circuit Bank 2P00AA is a generic OBD-II powertrain diagnostic trouble code: Intake Air Temperature Sensor 1 Circuit Bank 2. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P00AA means
DTC P00AA is stored when the PCM detects a general circuit malfunction on the Intake Air Temperature Sensor 1 (IAT1) located on Bank 2. Where IAT2 typically measures air temperature downstream of the intercooler or in the intake manifold, IAT1 is usually positioned upstream — in the air filter housing or inlet duct — and represents the ambient charge temperature before any boost-related heating. Bank 2 is the cylinder bank that does not contain cylinder #1 on V-layout engines. The P00AA code is a broad-spectrum fault that covers open circuits, short circuits, or an out-of-range signal on the Bank 2 IAT1 circuit; the PCM flags P00AA when the IAT1 signal does not fall within the expected voltage window (typically 0.2–4.8 V) or when no credible signal can be established at all. The PCM uses the Bank 2 IAT1 reading to set initial fuel enrichment strategy, calculate air density for accurate fuel metering, and cross-validate with the MAF sensor. An absent or invalid IAT1 signal forces the PCM to substitute a default value, degrading fuel economy and increasing emissions, while also potentially causing poor cold-start behaviour and rough running in temperature extremes.
Common causes
Most-frequently reported root causes when P00AA is logged.
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1
Failed IAT1 sensor on Bank 2 (open or short-circuit thermistor element)
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2
Open or broken signal wire between the Bank 2 IAT1 sensor and the PCM
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3
Short to ground on the IAT1 signal circuit pulling voltage below the lower threshold
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4
Short to voltage on the signal circuit pushing voltage above the upper threshold
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5
Corroded, loose, or damaged connector at the IAT1 sensor or PCM harness plug
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6
Missing or damaged 5 V reference supply from the PCM to the sensor
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7
PCM internal failure on the IAT1 input circuit (diagnose after ruling out wiring and sensor)
Symptoms drivers notice
How to diagnose P00AA
A typical diagnostic flow when this code is present.
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1
Connect an OBD-II scan tool and confirm P00AA is stored; check for related codes such as MAF faults or other IAT codes and record freeze-frame data
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2
With key on and engine cold, observe the Bank 2 IAT1 live reading against ambient temperature and the coolant temperature — a reading at -40 °C or above +120 °C indicates an out-of-range circuit condition
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3
Visually inspect the Bank 2 IAT1 sensor, connector, and wiring harness for physical damage, corrosion, oil contamination, or chafing against hot or sharp engine components
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4
Disconnect the IAT1 sensor and measure resistance across its two terminals at known ambient temperature; compare to OEM spec (approximately 2–3 kΩ at 20 °C); infinite resistance = open, near-zero = internal short
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5
With the sensor unplugged and ignition on, use a multimeter to verify the PCM is supplying approximately 5 V on the signal wire and that the ground wire measures less than 0.1 Ω to chassis ground
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6
Inspect the PCM-side connector for the IAT1 Bank 2 input pin; clean and re-seat if corrosion is present, then retest before condemning the PCM
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7
Replace the confirmed faulty sensor or repair damaged wiring, clear codes, and perform a test drive to verify no recurrence
Related powertrain codes
Frequently asked questions
What is the difference between IAT1 and IAT2?
On turbocharged or supercharged engines, IAT1 is typically located before the turbocharger or intercooler — measuring ambient inlet air temperature — while IAT2 measures post-intercooler charge temperature entering the intake manifold. On naturally aspirated V-engines, IAT1 and IAT2 may be in the left and right intake runners respectively. The distinction matters diagnostically because they monitor different parts of the air path.
Will P00AA cause the engine to run rich or lean?
It depends on what substitute value the PCM falls back to. Most PCMs default to a warm mid-range temperature estimate (around 25–40 °C). If actual ambient is much colder, the engine may run slightly lean on cold starts; if ambient is much hotter, it may run slightly rich. In either case, the deviation from ideal causes elevated emissions and efficiency losses.
Can a clogged air filter cause P00AA?
A clogged filter will affect airflow and could indirectly affect IAT readings if the sensor heats up due to reduced airflow, but it will not directly cause a circuit fault code like P00AA. The code specifically indicates an electrical problem in the sensor circuit — faulty wiring, sensor, or connection.
Should I replace the PCM if I cannot find the fault in the wiring?
PCM failure is rare and should be the last step. Before condemning the PCM, verify 5 V reference supply, inspect the PCM connector pin for corrosion, and try a known-good replacement sensor. If a known-good sensor and repaired wiring still produce the fault, consult the OEM service data for PCM diagnostics and consider having the module bench-tested.
Disabling P00AA in software
RaceTune can permanently disable P00AA — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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