Code P00A0: Definition and Causes of the Fault
The fault code P00A0 is a generic powertrain code. It indicates a problem in the Charge Air Cooler Temperature Sensor circuit, specifically on engine bank 2 (the bank that does not include cylinder number 1). This code applies to many vehicles equipped with a turbocharger (Chevrolet, Ford, Toyota, Audi, VW, etc.), but diagnostic procedures may vary by model.
Role of the Sensor and the Charge Air Cooler
The turbocharger forces air into the engine to increase its power. The compressed air becomes very hot and loses density. The charge air cooler (or intercooler), whether air-to-air or air-to-liquid, functions to cool this air before it enters the engine, restore its density, and thus optimize performance and fuel economy.
The Charge Air Cooler Temperature Sensor (CACT) measures the temperature of the cooled air. The Powertrain Control Module (PCM) uses this data, often comparing it with other data (intake temperature, coolant temperature), to calculate air density and adjust the air-fuel mixture.
Note: On some models, this sensor is integrated with the Manifold Absolute Pressure (MAP) sensor.
Symptoms and Severity of Code P00A0
The severity of this code is moderate. The vehicle usually remains drivable, but it may enter a reduced power mode (“limp mode”) to protect the engine.
Common symptoms include:
- Illuminated Check Engine Light
- Noticeable decrease in engine performance
- Reduced fuel economy
- Vehicle power limitation (limp mode)
- Inhibition of diesel particulate filter regeneration (on diesel engines)
Possible Causes of the P00A0 Fault
- Faulty CACT sensor (most common cause)
- Wiring problem (short circuit, open circuit, corroded or loose connector)
- Charge air cooler clogged or damaged
- PCM failure (rare)
Diagnosis and Repair Procedures
Before starting, consult your vehicle’s Technical Service Bulletins (TSBs) for any recalls or specific procedures.
1. Visual Inspection
Inspect the sensor, its electrical connector, and the associated wiring. Look for signs of corrosion, physical damage, or loose connections. Also check the condition of the charge air cooler and air ducts for possible leaks or obstructions.
2. Sensor and Circuit Testing
Diagnostic Tool Test: Using a scan tool, observe the CACT temperature value in real time. Unplug the sensor connector. The displayed value should drop sharply. Reconnect it and check that it rises again. This confirms that the PCM is receiving the signal.
Sensor Resistance Test: With the engine off, disconnect the sensor. Measure its resistance (in Ohms) between its two terminals using a multimeter. Compare the value with the manufacturer’s specifications (it normally decreases as the temperature increases). If the value is inconsistent or infinite (open circuit), the sensor is faulty.
3. Electrical Circuit Verification
5V Power Supply: Ignition on, engine off, use a multimeter (volts) to check for the presence of a 5V reference voltage between the power supply pin of the connector and ground. No voltage? Check the continuity between this pin and the corresponding pin at the PCM to identify a possible break.
Ground: Engine off, check the continuity (ohms) between the ground pin of the connector and a good chassis ground. A lack of continuity indicates a grounding problem.
4. Conclusion and Replacement
If the sensor and wiring are in good condition and the 5V signal is present, a PCM failure is possible but rare. In most cases, replacing the faulty Charge Air Cooler Temperature Sensor will resolve the problem. After any repair, clear the fault codes with the scan tool and perform a road test to verify that the fault does not reappear.
Call to Action: This procedure is generic. For an accurate diagnosis, always refer to the specific repair manual or wiring diagrams for your vehicle model. If you are not comfortable performing these procedures, consult a professional mechanic.