Chafed, cracked, or corroded wiring at the AAT sensor connector or along the harness run to the PCM.; A failing AAT sensor that goes open or short only when hot, cold, or wet.; Loose or backed-out terminals in the sensor pigtail or PCM connector causing an intermittent connection.; Water intrusion into the sensor body or connector, common when the sensor is mounted in a mirror or bumper area.; A poor ground or reference voltage shared with other sensors on the same circuit.; Aftermarket accessories such as remote starters or alarm systems tapping into the AAT wiring.; A PCM internal fault on the AAT input, which is rare but must be ruled out after wiring and sensor checks pass.

DTC codes / P00xx · Fuel and air metering and auxiliary emission controls / P00DD

P00DDAmbient Air Temperature Sensor Circuit B Intermittent/Erratic

P00DD means the powertrain control module (PCM) has detected an intermittent or erratic signal from the ambient air temperature (AAT) sensor circuit B, which is the second AAT sensor on vehicles that use more than one. The PCM expects a steady voltage or data message that changes smoothly with outside temperature, and it flags this code when the signal jumps, drops out, or behaves unpredictably.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

Often no symptoms besides the warning light, because the AAT sensor mainly trims climate control and remote start logic.
Outside temperature display on the dash reads dashes, blanks out, or jumps around erratically.
Automatic climate control blows the wrong temperature or fails to switch between fresh and recirculated air correctly.
Remote start or heated mirror and wiper functions may be inhibited when the PCM cannot trust the ambient temperature.
In some vehicles, a rough idle or slightly elevated idle speed right after a cold start as the PCM substitutes a default temperature.
Intermittent operation that appears only in wet weather, over bumps, or at certain temperatures.

Common causes, most likely first

Chafed, cracked, or corroded wiring at the AAT sensor connector or along the harness run to the PCM.
A failing AAT sensor that goes open or short only when hot, cold, or wet.
Loose or backed-out terminals in the sensor pigtail or PCM connector causing an intermittent connection.
Water intrusion into the sensor body or connector, common when the sensor is mounted in a mirror or bumper area.
A poor ground or reference voltage shared with other sensors on the same circuit.
Aftermarket accessories such as remote starters or alarm systems tapping into the AAT wiring.
A PCM internal fault on the AAT input, which is rare but must be ruled out after wiring and sensor checks pass.

How to diagnose and fix it

Scan all modules and record freeze-frame data for P00DD, then clear the code and test-drive while watching live AAT data for dropouts or jumps.
Inspect the AAT sensor connector and the harness run for chafing, corrosion, or water intrusion, wiggling the harness while watching the live data.
Measure resistance across the AAT sensor at known temperatures and compare to the manufacturer's resistance chart, then check for opens or shorts when the sensor is warmed or cooled.
Back-probe the sensor signal and ground wires at the PCM and check for voltage drops or intermittent continuity while flexing the harness.
Check for shared reference or ground circuits that other sensors use, since a fault there can make the AAT signal erratic without the AAT sensor itself being bad.
Replace the AAT sensor only after wiring and signal checks confirm the sensor is the source of the erratic signal.
Clear codes and verify the repair with a long test drive that includes bumps, temperature swings, and wet conditions if the fault was intermittent.

Why an intermittent AAT code fools parts cannons

AAT circuit B is often the second ambient sensor used for a specific function such as mirror heating or remote start, so the primary outside temperature display can look normal while this code sets.
The most common cause is not the sensor but a chafed wire in the door jamb, bumper, or mirror fold area where the harness flexes every time the vehicle is used.
A generic scan tool may show AAT data that looks plausible because the PCM substitutes a default value when the signal is erratic, so live data must be watched during a wiggle test rather than read once.
Aftermarket remote starters and alarm installers frequently splice into the AAT circuit, and those splices corrode and cause intermittent faults that look like a failed sensor.
This code does not mean the engine coolant temperature sensor is faulty, even though both sensors influence cold-start fuel and idle strategy, so do not replace the coolant sensor on this code alone.

Can I keep driving with P00DD?

The vehicle is safe to drive because the ambient air temperature sensor does not control engine operation directly, but avoid relying on remote start, automatic climate control, or heated mirror functions until the fault is repaired. If the code appears alongside drivability codes, diagnose those first because they may share a reference or ground circuit.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.