P00A3: Charge Air Cooler Temperature Sensor Circuit High Bank 2

What it means

The charge air cooler temperature sensor circuit signal for Bank 2 is higher than expected.

At a glance

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

How it works

The Bank 2 charge air cooler temperature sensor measures compressed-air temperature after the cooler and sends a signal to the control module. P00A3 sets when that signal is higher than expected, which can result from an open signal path or an unintended connection to a positive-voltage source.

Common causes

Most likely first.

1. Signal wire open
2. Connector pins corroded - high contact resistance
3. Supply wire pinched against B+ source

Symptoms

• Check engine light on
• Reduced engine performance or boost
• Poor fuel economy

How to diagnose it

1. Review freeze-frame and live data to confirm the Bank 2 temperature reading is high and compare it with ambient temperature or the other bank.
2. Inspect the Bank 2 sensor connector for poor seating and the harness for an open, pinched section, or contact with a positive-voltage wire.
3. Using the manufacturer's wiring diagram, test the Bank 2 signal circuit for an open and for a short to battery voltage.
4. Check the sensor reference and ground connections at the Bank 2 connector using manufacturer procedures.
5. If the circuit checks out, test the Bank 2 sensor and control-module input before replacing either part.

Common fixes

• Repair an open Bank 2 signal wire or damaged harness section.
• Repair insulation where the signal wire contacts a positive-voltage source.
• Restore secure contact at loose or corroded Bank 2 connector terminals.
• Replace a Bank 2 sensor or repair a module only when testing identifies it as faulty.

Can I keep driving?

If the engine runs normally, drive gently to a repair location; the control module may reduce boost or power when Bank 2 temperature data is unreliable. Avoid towing and hard acceleration until the circuit is fixed.