U0612: Lost Communication With Intake Air Temperature Sensor 1 Bank 2

What it means

The vehicle bus reports loss of communication with smart IAT sensor 1 on bank 2. Charge-air density correction reverts to a substitute value.

At a glance

• Usually lights the warning light of the system that lost communication
• Affects emissions; the car can fail an emissions test

How it works

The smart intake air temperature sensor 1 on bank 2 measures incoming or charge-air temperature and reports it over the vehicle communication bus. U0612 sets when the control module stops receiving messages from the bank 2 sensor 1, and charge-air density correction may then rely on a substitute value.

Common causes

Most likely first.

1. Bus wiring open or shorted
2. Module without power or ground
3. Module failed

Symptoms

• Multiple warning lights may illuminate
• Affected modules may go into limp mode or shut down
• Specific functions inoperative depending on module
• Diagnostic tools may show communication faults

How to diagnose it

1. Record freeze-frame data and scan all modules for related communication faults to see whether the bank 2 sensor fault is part of a wider bus or power issue.
2. Check live data for bank 2 IAT sensor 1 and compare it with ambient temperature and corresponding bank 1 readings to identify a missing or implausible signal.
3. Inspect the bank 2 sensor 1 connector and its bus wiring for looseness, corrosion, damaged insulation, heat exposure, or water entry.
4. Check power and ground at the bank 2 sensor module using the manufacturer's wiring information.
5. Test the communication wires for opens or shorts according to the manufacturer's procedure and repair any fault found.
6. If the circuit and module power are sound, confirm that the bank 2 sensor 1 module is transmitting before replacing it.

Common fixes

• Reconnect and secure the bank 2 IAT sensor 1 connector.
• Clean corrosion or repair damaged terminals at the bank 2 sensor 1 connector.
• Repair an open, short, or damaged section of the bank 2 sensor communication wiring.
• Restore the sensor module's power or ground connection.
• Replace the bank 2 IAT sensor 1 module if it fails testing with a verified circuit.

Can I keep driving?

A short, gentle trip may be possible if the engine runs normally and there are no temperature warnings, but have the communication fault diagnosed soon because charge-air correction and emissions control may be affected. Stop if the engine overheats, loses power, or enters limp mode.