Fuel and air

P00A2 — Charge Air Cooler Temperature Sensor Circuit Low (Bank 2)

Severity: medium Drive with care, to a shop

What P00A2 means

The engine control unit monitors the voltage from the charge air cooler (intercooler) temperature sensor on bank 2. The sensor is a thermistor, so its signal voltage drops as the air gets hotter. P00A2 sets when that voltage stays below the expected range, which the ECU reads as an unrealistically high temperature. The usual culprits are a short to ground in the signal wire or a failed sensor.

Symptoms

  • Check Engine light on
  • Reduced power and sluggish acceleration
  • Worse fuel economy
  • Irregular or reduced boost
  • Possible limp mode

Possible causes

  1. Failed charge air temperature sensor
  2. Signal wire shorted to ground or damaged wiring insulation
  3. Moisture or corrosion in the sensor connector
  4. Poor connection or damaged terminals
  5. Intercooler or hose problem near the sensor (uncommon)
  6. Faulty ECU (rare)

How to diagnose

  1. Scan all codes and freeze frame data, clear the code and see if it returns
  2. Inspect the bank 2 sensor, connector and harness for chafing, oil, moisture and corrosion
  3. Check live data for charge air temperature: on a cold engine it should be close to ambient
  4. Unplug the sensor and watch the reading; it should swing to the open-circuit extreme, which points to the sensor or its wiring as the source of the low signal
  5. Measure the sensor resistance and compare it with the spec for your model
  6. Test the signal wire for a short to ground and confirm the 5 V reference at the connector
  7. Inspect the intercooler and boost pipes for damage or leaks
  8. If wiring and sensor are good, check the ECU and its connectors

Common fixes

  • Replace the charge air temperature sensor
  • Repair the wiring harness or replace the damaged connector and terminals
  • Clean and dry the connector and replace seals
  • Replace the intercooler if it is the source of the fault
  • Repair or reflash the ECU (last resort)

Questions and answers

What does P00A2 mean?

It means the bank 2 charge air cooler temperature sensor circuit is reporting a low signal. The ECU thinks the air is extremely hot, but the cause is usually a short or a bad sensor.

Can I drive with code P00A2?

For a short trip to a shop, usually yes, but expect less power and higher fuel use. Don't put off the repair, to avoid straining the engine and turbo.

How can I quickly test the sensor?

Compare its reading on a cold engine with the outside temperature, then measure its resistance against the manufacturer's table. Also check the connector and wires for moisture or shorts.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.