A failed exhaust gas temperature sensor at bank 2, sensor 3, typically an open or shorted thermocouple element.; Damaged, chafed, or corroded wiring between that sensor and the module that reads it, especially near hot exhaust components.; A loose or contaminated connector at the sensor or at the module, often caused by oil, coolant, or road splash ingress.; A faulty module that reads the sensor, such as the engine control module or aftertreatment control module, failing to broadcast the signal on the CAN bus.; CAN bus wiring faults, including a short to ground or power, an open circuit, or excessive resistance on the bus pair.; A weak or failing battery or charging system that causes low voltage and intermittent module dropouts.; Aftermarket accessories or poor previous repairs that disturb the bus wiring or introduce electrical noise.

DTC codes / U06xx · Network communication / U069C

U069CLost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 3

U069C is a 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 assigned to bank 2, sensor 3. The module monitoring that sensor, typically the engine control module or a dedicated aftertreatment controller, has stopped receiving valid temperature data over the bus for a calibrated period, 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 display, often with no other symptoms besides the warning light.
Reduced engine power or a limp-home mode if the module substitutes a default exhaust temperature and limits regeneration or fueling.
A diesel particulate filter (DPF) regeneration that never completes or a regeneration that runs far too often.
Poor fuel economy or increased exhaust smoke if the engine control strategy defaults to a rich or retarded timing map.
Intermittent warning light that comes and goes with vibration, moisture, or temperature changes.
Other communication codes stored in multiple modules if the fault lies on the shared bus rather than at the sensor.

Common causes, most likely first

A failed exhaust gas temperature sensor at bank 2, sensor 3, typically an open or shorted thermocouple element.
Damaged, chafed, or corroded wiring between that sensor and the module that reads it, especially near hot exhaust components.
A loose or contaminated connector at the sensor or at the module, often caused by oil, coolant, or road splash ingress.
A faulty module that reads the sensor, such as the engine control module or aftertreatment control module, failing to broadcast the signal on the CAN bus.
CAN bus wiring faults, including a short to ground or power, an open circuit, or excessive resistance on the bus pair.
A weak or failing battery or charging system that causes low voltage and intermittent module dropouts.
Aftermarket accessories or poor previous repairs that disturb the bus wiring or introduce electrical noise.

How to diagnose and fix it

Scan all modules for stored and pending codes, record freeze-frame data, and verify whether U069C is the only code or part of a larger communication pattern.
Inspect the bank 2 sensor 3 connector and the full harness run for chafing, heat damage, corrosion, or loose pins, and repair any obvious wiring fault first.
Measure the sensor's resistance or voltage output at the connector and compare it with the manufacturer's specification for the current exhaust temperature.
Check CAN bus integrity with a multimeter or oscilloscope, measuring resistance between the bus lines and checking for shorts to ground or power.
Verify module power, ground, and wake-up signals at the module that reads the EGT sensor, since a low-voltage dropout can mimic a sensor fault.
If the sensor and wiring test good, substitute a known-good sensor or perform a module software update or replacement only after confirming the bus and power supplies are sound.
Clear codes, road-test the vehicle through several drive cycles, and confirm that the EGT reading updates live and that U069C does not return.

What the code does not always mean

U069C is a communication code, so it does not prove the EGT sensor itself has failed; a module that stops broadcasting the sensor value will set the same code even with a perfectly good sensor.
A weak battery or a failing alternator frequently causes intermittent U-codes across several modules, and replacing the EGT sensor first is a common and expensive misdiagnosis.
Heat-related harness damage near the turbocharger or DPF is easy to miss on a visual inspection because the insulation can look intact while the conductor inside is broken.
Aftermarket remote starters, alarms, or poor audio installs that tap into the CAN bus can introduce enough noise to drop the EGT message and set U069C.
On some vehicles the EGT sensor is read by a separate aftertreatment module rather than the engine control module, so the fault may follow that module's power and ground rather than the sensor circuit.

Can I keep driving with U069C?

The vehicle is usually safe to drive to a repair shop because the fault is a communication loss rather than a mechanical failure, but avoid long trips, heavy towing, or sustained high-load driving until it is diagnosed. If the engine enters limp mode or regeneration stops completing, limit driving and have it inspected promptly to prevent DPF damage.

Tools that help

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