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DTC codes / U06xx · Network communication / U0622

U0622Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 2

U0622 is a generic network communication code indicating that a control module on the vehicle's Controller Area Network (CAN) bus has lost contact with the exhaust gas temperature (EGT) sensor for bank 2, sensor 2. The module monitoring that sensor—typically the engine control module (ECM) or a dedicated aftertreatment control module—has stopped receiving valid temperature data over the communication network, so it sets this code and may substitute a default value.

SystemNetwork
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaNetwork communication

Symptoms you may notice

  • Illumination of the check engine light or a message on the driver information center, often with no other noticeable symptoms.
  • Reduced engine power or limp mode if the ECM cannot determine exhaust temperatures and chooses to protect the aftertreatment system.
  • Poor fuel economy or altered regeneration behavior on diesel vehicles equipped with a particulate filter.
  • Intermittent or erratic temperature readings on a scan tool data stream for bank 2 sensor 2.
  • Possible failure of the vehicle to complete an active regeneration cycle, leading to a soot load warning.
  • No drivability change at all in many cases, because the fault is a communication loss rather than a sensor performance failure.

Common causes, most likely first

  1. A faulty exhaust gas temperature sensor on bank 2 sensor 2 that has failed internally and stopped responding on the network.
  2. Damaged, chafed, or corroded wiring between the EGT sensor and its control module, especially near hot exhaust components.
  3. A poor or corroded electrical connector at the sensor or at the module, causing an intermittent open circuit on the communication line.
  4. A failed or failing control module that is no longer communicating properly with the sensor or the rest of the network.
  5. A CAN bus communication fault, such as a shorted or open data line, that affects the module responsible for the EGT sensor.
  6. Low battery voltage or a charging system problem that causes modules to drop offline intermittently.
  7. Aftermarket accessories or poor previous repairs that introduce electrical noise or incorrect wiring into the sensor circuit.

How to diagnose and fix it

  1. Connect a scan tool and record all stored and pending codes, then check the live data for bank 2 sensor 2 exhaust temperature to see whether the value is stuck, missing, or erratic.
  2. Visually inspect the EGT sensor, its connector, and the wiring harness for damage, corrosion, or contact with hot exhaust parts, repairing any obvious faults.
  3. Measure resistance and voltage on the sensor circuit according to the manufacturer's service information to confirm whether the sensor or the wiring is at fault.
  4. Check battery voltage and charging system output, and clear the code to see whether it returns immediately or only under specific conditions.
  5. If the sensor circuit tests good, perform a network communication check to confirm whether the control module that owns the sensor is online and communicating.
  6. Replace the exhaust gas temperature sensor only after confirming the wiring and module are healthy, then clear codes and verify the live data reads correctly.
  7. If communication faults persist, diagnose the CAN bus for opens, shorts, or excessive resistance and repair the affected section of the network.

What a communication code really tells you

  • U0622 is a communication code, not a sensor performance code, so the sensor itself may be perfectly functional while the real fault lies in the wiring or the module that reports its data.
  • Technicians often replace the EGT sensor first and find the code returns because the actual problem was a corroded connector pin or a chafed wire near the exhaust manifold.
  • A weak battery or failing alternator can cause multiple U-codes to appear at once, and U0622 may be a symptom of low voltage rather than a dedicated sensor fault.
  • On some vehicles the EGT sensor reports to a separate aftertreatment module rather than the ECM, so a fault in that module can set U0622 even when the sensor circuit is intact.
  • Aftermarket remote starters, alarms, or poor audio installations can introduce electrical noise on the CAN bus and trigger communication codes that disappear once the accessory is removed.

Can I keep driving with U0622?

You can usually continue driving to a workshop, but avoid heavy loads and long trips if the vehicle has entered limp mode or if regeneration is inhibited, because unresolved exhaust temperature faults can lead to expensive aftertreatment damage. Have the fault diagnosed promptly rather than clearing the code and ignoring it.

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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