P00EF: Intake Air Temperature Sensor 3 Circuit Low Bank 2

What it means

The intake air temperature sensor 3 circuit signal on bank 2 is below the expected range.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

Intake air temperature sensor 3 on bank 2 sends an air temperature signal to the engine control module. This code sets when the bank 2 sensor 3 signal falls below the expected electrical range, which can happen when the signal wire is grounded or damaged.

Common causes

Most likely first.

1. Signal wire shorted to ground
2. Connector pins corroded - high contact resistance
3. Harness chafing through insulation

Symptoms

• Check-engine light on
• Reduced engine performance or power
• Poor fuel economy

How to diagnose it

1. Save freeze-frame data and compare bank 2 sensor 3 live data with other intake temperature readings for an unusually low or fixed value.
2. Inspect the bank 2 sensor 3 harness for chafing, crushed sections, or insulation worn through near metal edges or moving parts.
3. Check the connector for corrosion and examine whether moisture or damaged terminals could be affecting the signal.
4. Using the wiring diagram, test the signal circuit for a short to ground and check continuity through the harness.
5. Test the sensor and circuit against the manufacturer's specification to distinguish a sensor fault from a wiring short.

Common fixes

• Repair chafed insulation or a signal wire shorted to ground.
• Clean corroded connector pins and restore proper terminal contact.
• Replace damaged sections of the bank 2 sensor 3 harness.
• Replace the sensor if it fails testing after the circuit is confirmed sound.

Can I keep driving?

If the engine runs normally, a gentle trip to have the fault checked is generally reasonable; avoid heavy loads if power is reduced. The low bank 2 temperature signal can impair engine control and fuel economy, so stop if drivability becomes poor.