Signal wire shorted to ground, for example chafed insulation against bodywork or the engine; Faulty intake air temperature sensor 3 with an internal short; Water or corrosion in the sensor connector bridging the signal and ground pins; Signal and sensor ground wires shorted together inside the harness or connector; Damaged or poorly fitted connector terminals causing a partial short; Fault inside the engine control unit's input circuit.

P00EF

Intake Air Temperature Sensor 3 Circuit Low Bank 2.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
0: AreaFuel and air metering, auxiliary emission controls
EF: FaultThe specific fault in that area

What it means

P00EF means the engine control unit has seen the signal voltage from intake air temperature sensor 3 on bank 2 fall below the expected range. The sensor is normally a temperature-sensitive resistor, so a very low voltage reads as an implausibly high air temperature. This usually points to a short to ground in the signal circuit or a failed sensor. Where sensor 3 sits (manifold, charge air pipe or elsewhere) depends on the engine.

Symptoms

Engine warning light on
Poor or hesitant acceleration if the control unit applies a default air temperature
Rough idle or unstable running in some cases
Hard starting, especially when cold
Slightly higher fuel consumption
Reduced boost or power on turbocharged engines if protection strategies are active

Possible causes

Signal wire shorted to ground, for example chafed insulation against bodywork or the enginelikely
Faulty intake air temperature sensor 3 with an internal shortlikely
Water or corrosion in the sensor connector bridging the signal and ground pinspossible
Signal and sensor ground wires shorted together inside the harness or connectorpossible
Damaged or poorly fitted connector terminals causing a partial shortpossible
Fault inside the engine control unit's input circuitrare

How to diagnose

Read all stored codes and freeze frame data, noting engine temperature, load and whether other intake air temperature codes are set
Check the manufacturer's information to identify where sensor 3 and bank 2 are on this engine
Inspect the sensor, connector and harness for chafing, heat damage, water ingress, corrosion and bent or pushed-back terminals
With the sensor connected, view live data: a reading far above ambient or stuck at a maximum value suggests a short or sensor fault
Compare the sensor reading with other intake air temperature sensors and the ambient temperature on a cold engine
Unplug the sensor and check the live reading: if it moves to the open-circuit default, the sensor is likely faulty; if it stays low, the wiring is shorted
Measure the sensor resistance and compare it with the specification at the current temperature
Check the signal wire for continuity and for a short to ground or to the sensor ground with the control unit connector disconnected

How to fix

Repair or replace the damaged section of wiring and secure it away from sharp edges and heat
Replace intake air temperature sensor 3 if its resistance is out of specification or shorted
Clean, dry and repair the connector, or replace the connector or terminals if corroded or damaged
Repair any short between the signal and ground wires in the harness
Replace or repair the engine control unit only after the sensor, wiring and connectors have been proven good

Can I keep driving?

Low severity

The car can usually be driven for a short time, but the control unit may be using a default air temperature, so book it in soon. If you notice power loss, rough running or poor starting, have it checked sooner.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.