Code
P00A3
Generic
P — Powertrain
Charge Air Cooler Temperature Sensor Circuit High Bank 2
Views:
UK: 24
EN: 40
RU: 33
AI status
Completed
Completed
100%
Causes
- Open or disconnected charge air cooler temperature sensor (Bank 2)
- Damaged wiring (broken conductor) between sensor and PCM
- Corroded/loose connector or poor terminal contact at the sensor or PCM
- Short to battery/ignition voltage (sensor signal wire tied to power)
- Faulty sensor (internal failure or water ingress)
- Poor ground or reference voltage problem from PCM
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated with P00A3 stored
- Incorrect charge-air/intercooler temperature reading in scan tool (very high or pegged high)
- Reduced engine performance or limp-home mode in some vehicles due to control strategy
- Turbo boost control problems or reduced turbo operation
- Reduced fuel/air trim accuracy; possible increased emissions
- Cooling fan or charge-air control logic operating oddly (thermal-related)
What to check
- Read and record PIDs/freeze frame with a scan tool (check charge air cooler temp, intake air temp, and related sensors)
- Visually inspect the sensor, connector, and wiring on Bank 2 for damage, corrosion, or water ingress
- With ignition ON (engine OFF) backprobe sensor signal and reference wires: verify reference voltage (typically ~5V) and sensor signal voltage
- Measure sensor resistance at ambient temperature and compare to expected spec (consult vehicle data)
- Check continuity from sensor connector to PCM and for shorts to battery voltage and ground
- Wiggle the wiring while monitoring live data to see if fault is intermittent
Signal parameters
- Typical reference voltage: ~5.0 V (varies by manufacturer)
- Normal signal range: ~0.1–4.9 V depending on temperature; circuit high means signal is above the PCM high threshold (often >4.8 V)
- NTC thermistor behavior: resistance decreases as temperature rises (resistance high at cold, low at hot)
- Typical resistance examples (vehicle-specific): ~2–4 kΩ at ~25 °C, falling toward
Diagnostic algorithm
- Retrieve and record freeze-frame data and live PIDs for charge-air temp (Bank 2), intake temp, and reference voltage.
- Visually inspect the Bank 2 charge-air cooler temp sensor, connector, and harness for damage, oil/water, or corrosion. Repair or protect any obvious damage.
- With ignition ON (engine OFF) backprobe the sensor connector: verify reference voltage (≈5 V) and measure sensor signal voltage. If signal is high (near reference) proceed to step 4.
- Measure sensor resistance at ambient temperature (disconnect sensor). Compare to OE specification or a replacement sensor. If resistance is open/infinite or out of range, replace the sensor.
- If sensor resistance is OK, check wiring continuity between sensor and PCM signal and reference pins. Repair any open or high-resistance circuits.
- Check for short to battery/ignition voltage on the signal wire (measure between signal wire and battery positive). If present, isolate and repair the short.
- Verify good ground and power supplies to PCM and related circuits. Repair grounds if high resistance.
- If wiring and sensor check good, consider PCM input fault — consult manufacturer procedures before replacing PCM.
- After repairs, clear codes and perform a test drive/functional verification while monitoring live data to confirm the fault does not return.
Likely causes
- Open circuit at sensor pigtail or connector (most common)
- Corroded pins or water intrusion in intercooler sensor connector
- Wire chafed and shorted to constant 12V or accessory feed
- Failed NTC thermistor element inside sensor
- Pin pushed out or poor crimp at harness connector
Fault status
Status
PCM detected a high-voltage/out-of-range signal from the Bank 2 charge air cooler temperature sensor circuit (P00A3). Possible open circuit, short to voltage, faulty sensor, wiring/connectors, or PCM input fault. MIL may be illuminated.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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