P00A1

What it means

P00A1 means the engine control unit has judged the signal from the charge air cooler (intercooler) temperature sensor on bank 2 to be implausible, even though the circuit is not completely open or shorted. It usually sets when the reading is stuck, responds too slowly, or disagrees with other temperature readings such as intake air, ambient or coolant temperature after a cold soak. Sensor position and bank numbering depend on the engine, so check the model-specific layout.

Symptoms

• Engine warning light on
• Reduced power or limp mode, as boost may be limited
• Hesitation or poor throttle response under load
• Slightly higher fuel consumption
• Rough running or uneven performance, mainly on twin-turbo or V-layout engines
• No noticeable symptoms other than the stored code

Possible causes

• Faulty or drifting charge air cooler temperature sensor on bank 2 (reading stuck, slow or offset)likely
• Damaged, corroded or loose connector or terminals at the sensorlikely
• Wiring fault such as chafing, high resistance or an intermittent open or short in the signal or reference linespossible
• Heat soak, oil contamination or a damaged or dirty sensor tip from a leaking charge air hose or coolerpossible
• Charge air leak or restricted cooler causing temperatures that do not match the expected valuespossible
• Fault in a related temperature sensor (intake air or ambient) used for the plausibility comparisonrare
• Engine control unit fault or outdated software, where the manufacturer lists one as a known causerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting engine temperature, load and ambient conditions when the code set.
2. Check for related codes on other intake air, charge air or boost sensors, as these point to a shared wiring or reference fault.
3. Visually inspect the bank 2 sensor, its connector and the wiring for damage, oil, water, heat damage or chafing.
4. With the engine fully cold, compare the live charge air cooler temperature with the intake air, coolant and ambient readings; they should be close.
5. Watch the live reading while warming up and under load; look for a stuck, jumping or very slow reading.
6. Check the sensor's resistance against the manufacturer's specification at a known temperature, and check the wiring for continuity and shorts, and for correct reference voltage at the plug.
7. Inspect the charge air hoses, clamps and cooler for leaks, oil contamination or blockage, and carry out a boost leak test if indicated.
8. Check for any manufacturer service information or software updates relating to this code for the specific model.

How to fix

• Replace the bank 2 charge air cooler temperature sensor if its readings or resistance are out of specification.
• Repair or replace the damaged connector, terminals or wiring, and clean any contamination from the connector.
• Repair charge air leaks, replace split hoses or faulty clamps, or deal with a blocked or leaking charge air cooler.
• Replace any other temperature sensor found to be faulty during the plausibility comparison.
• Apply a manufacturer-issued software update only if an outdated calibration is a documented cause for this model.
• Clear the code after repair and road test to confirm it does not return.

Can I keep driving?

Nearby codes

• P00A0GenericCharge Air Cooler Temperature Sensor Circuit Bank 2
• P00A2GenericCharge Air Cooler Temperature Sensor Circuit Low Bank 2