Damaged, corroded or disconnected wiring and connector pins at the intake air temperature sensor; A failed intake air temperature sensor that no longer transmits data on the network; A break or short in the communication bus wiring between the sensor and the module that owns it; A faulty module on the same network segment interrupting communication; Water or oil intrusion into the sensor connector causing signal loss; A blown fuse or poor ground shared by the sensor circuit

DTC codes / U06xx · Network communication / U0611

U0611Lost Communication With Intake Air Temperature Sensor 1 Bank 1

This code means the engine control module has lost the data signal from the intake air temperature sensor on bank 1, so it no longer knows the temperature of the air entering the engine. The module sets U0611 when the expected message from that sensor stops arriving on the communication network for a set period.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaNetwork communication

Symptoms you may notice

Illuminated check engine light, often with no other symptoms besides the warning light
Rough idle or unstable running shortly after a cold start
Poor fuel economy as the module substitutes a default air temperature value
Hesitation or flat spots during acceleration when the engine is warming up
A stored code in a related module, such as the transmission control module, reporting a missing signal

Common causes, most likely first

Damaged, corroded or disconnected wiring and connector pins at the intake air temperature sensor
A failed intake air temperature sensor that no longer transmits data on the network
A break or short in the communication bus wiring between the sensor and the module that owns it
A faulty module on the same network segment interrupting communication
Water or oil intrusion into the sensor connector causing signal loss
A blown fuse or poor ground shared by the sensor circuit

How to diagnose and fix it

Scan all modules for stored codes and record which modules report the missing signal
Inspect the intake air temperature sensor connector and wiring for corrosion, looseness or damage
Check the sensor circuit for power, ground and communication voltage with a multimeter
Test the intake air temperature sensor signal against a known good value or substitute a known good sensor
Check the communication bus wiring for continuity and shorts between the sensor and its controlling module
Verify shared fuses and grounds for the sensor and network are intact
Clear the code and road test to confirm the signal returns and the code does not reset

Why this code often is not the sensor

A U0611 is a communication fault, so the sensor itself may be healthy while the wiring or a network module is the real cause.
Technicians often replace the intake air temperature sensor only to find a corroded connector pin or a chafed bus wire behind the engine.
A weak battery or charging system can drop network voltage briefly and set communication codes that disappear after a reset.
Other modules on the same bus can interrupt the signal, so always scan every module before condemning the sensor.
The engine may run almost normally because the control module substitutes a default air temperature, hiding the fault from the driver.

Can I keep driving with U0611?

The vehicle is usually safe to drive to a workshop because the engine control module substitutes a default air temperature, but avoid heavy load or long trips until the fault is repaired. If the engine runs roughly or stalls, stop driving and have the circuit inspected promptly.

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.