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DTC codes / P06xx · Computer and output circuits / P06AA

P06AAControl Module Internal Temperature B Too High

P06AA indicates that the control module responsible for monitoring internal temperature has detected its 'B' temperature sensor reading excessively high, often due to a fault in the module's internal thermal management or a related circuit. The computer sets this code when the internal temperature exceeds a calibrated threshold, typically to protect the electronics from heat damage.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyProfessional
AreaComputer and output circuits

Symptoms you may notice

  • Illumination of the check engine light or service engine soon light, often with no other noticeable symptoms.
  • Intermittent electrical glitches such as flickering dashboard lights or erratic gauge behavior.
  • Reduced performance or limp mode if the module enters a protective strategy.
  • Hard starting or stalling if the affected module controls engine functions.
  • Overheating warnings or messages on the driver information display.
  • No symptoms besides the warning light in many cases, especially if the fault is intermittent.

Common causes, most likely first

  1. Faulty internal temperature sensor B within the control module.
  2. Poor electrical connection or damaged wiring to the module's temperature sensing circuit.
  3. Overheating of the control module due to a failed cooling fan or blocked ventilation.
  4. Software error in the module causing false high-temperature readings.
  5. Voltage supply issues or ground problems leading to incorrect sensor readings.
  6. Physical damage or corrosion inside the module affecting temperature sensing.
  7. Extreme underhood temperatures from other faults, such as a restricted exhaust or cooling system failure.

How to diagnose and fix it

  1. Use an OBD-II scanner to verify the code and check for related freeze-frame data, then clear the code to see if it returns.
  2. Inspect the control module's wiring harness and connectors for signs of damage, corrosion, or loose pins.
  3. Check the module's cooling system, including fans and ventilation paths, for proper operation and obstructions.
  4. Measure the module's supply voltage and ground circuits to ensure they are within specification.
  5. Consult the factory service information for specific pinpoint tests for the internal temperature sensor circuit.
  6. If the sensor circuit tests good, reflash or reprogram the module with the latest software from the manufacturer.
  7. Replace the control module if internal sensor failure is confirmed and all external factors are ruled out.

Hidden Causes of P06AA You Might Overlook

  • A failing cooling fan or a blocked air duct to the module can cause overheating that triggers this code, even if the module itself is healthy.
  • In some vehicles, a low battery or charging system issue can cause voltage spikes that confuse the module's temperature sensing, leading to a false P06AA.
  • The code may be set by a software glitch that can be resolved with a simple reflash, so avoid replacing the module before checking for updates.
  • Corroded grounds or poor connections at the module can mimic an internal sensor failure, so always perform a thorough visual and voltage drop test.
  • P06AA is often accompanied by other codes related to the same module; diagnosing those first can provide clues to the root cause.

Can I keep driving with P06AA?

If the check engine light is on but the vehicle runs normally, you can drive cautiously to a repair shop, but avoid heavy loads or long trips. If the vehicle enters limp mode or shows overheating warnings, stop driving and seek professional assistance to prevent module damage.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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