P00A7
Intake Air Temperature Sensor 2 Circuit Low Bank 2P00A7 is a generic OBD-II powertrain diagnostic trouble code: Intake Air Temperature Sensor 2 Circuit Low 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 P00A7 means
DTC P00A7 is set when the PCM detects a lower-than-expected voltage on the Intake Air Temperature (IAT) Sensor 2 signal circuit for Bank 2 — the engine bank that does not contain cylinder #1. The IAT sensor is a Negative Temperature Coefficient (NTC) thermistor: its resistance decreases as temperature rises, which raises the circuit voltage the PCM sees. A circuit-low condition therefore means the PCM is reading a voltage that corresponds to an unrealistically high temperature, typically caused by a short to ground on the signal wire, a failed sensor whose internal resistance has dropped to near zero, or a missing reference voltage. The PCM uses IAT2 Bank 2 data to refine fuel injection quantity, ignition timing, and — on turbocharged engines — boost management. With the signal pulled low, the PCM may interpret the intake air as being extremely hot, leading it to retard timing or lean out fuelling unnecessarily, which can produce hesitation, increased emissions, and minor performance loss. The code may also be associated with elevated NOx output during emissions testing. Diagnosis should begin with a simple sensor-disconnect test to determine whether the low voltage is coming from the sensor itself or from a wiring short downstream of the connector.
Common causes
Most-frequently reported root causes when P00A7 is logged.
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1
Internally shorted IAT sensor 2 with near-zero resistance across its terminals
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2
Signal wire shorted to ground or to another low-voltage wire in the harness
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3
Damaged or pinched wiring harness creating an unintended ground path on the signal circuit
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4
Corroded connector terminals creating a resistive bridge between signal and ground pins
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5
Loss of 5 V reference voltage from the PCM forcing the signal rail low (open reference)
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6
Moisture intrusion into the connector causing a short-to-ground
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7
PCM internal fault on the IAT2 Bank 2 signal input
Symptoms drivers notice
How to diagnose P00A7
A typical diagnostic flow when this code is present.
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1
Connect a scan tool and read IAT2 Bank 2 live data — a reading at or near the sensor's maximum temperature limit (e.g. 150 °C+ at ambient) confirms the circuit-low/signal-high-temperature condition
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2
Disconnect the IAT2 sensor connector and observe the scan tool reading; if it drops to the open-circuit floor (minimum temperature rail, typically -40 °C / -40 °F), the short is in the sensor itself
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3
If the reading does not drop after disconnecting the sensor, the short is in the wiring harness — probe the signal wire with ignition on for voltage and check continuity to ground with ignition off
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4
Inspect the harness from the sensor connector to the PCM for pinch points, chafing, or moisture ingress; pay attention to sharp body edges and hot zones near the exhaust
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5
With the sensor unplugged, measure resistance across the sensor's two terminals; near-zero resistance at ambient temperature confirms an internally shorted sensor
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6
Verify the 5 V reference is present at the harness-side connector with ignition on; a missing reference points to a PCM output fault or an open reference wire
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7
Repair any confirmed short or open, clear codes, and retest with a live data log to confirm the signal tracks properly with temperature changes
Related powertrain codes
Frequently asked questions
Why does circuit-low mean the PCM thinks the temperature is high?
The IAT sensor is an NTC thermistor — lower resistance equals higher voltage return in most implementations... wait, actually: the PCM sends a 5 V reference through a pull-up resistor. As sensor resistance decreases (hotter air), the signal voltage drops. So a short to ground (near-zero resistance) makes the PCM see maximum temperature. This is the inverse of how it might seem intuitively.
Can P00A7 cause engine knocking?
Potentially yes — if the PCM interprets the falsely high IAT reading as extremely hot intake air, it may retard ignition timing. However, in some implementations the retard is modest and knock may not be perceptible. Sustained operation with incorrect timing is nevertheless undesirable and should be repaired promptly.
Is P00A7 specific to turbocharged engines?
No — both naturally aspirated and turbocharged engines use IAT sensors, and P00A7 can appear on either. The consequences are more pronounced on turbocharged engines because boost management also depends on accurate air temperature data.
How do I confirm the short is in the harness and not inside the PCM?
Disconnect both the sensor connector and the PCM connector for Bank 2 IAT2. Measure resistance from the signal pin at the sensor end of the harness to ground. If continuity exists with both ends disconnected, the harness itself has a short to ground that must be repaired before the PCM can be cleared of suspicion.
Disabling P00A7 in software
RaceTune can permanently disable P00A7 — 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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