U068F: Lost Communication With EGR Temperature Sensor C

What it means

The vehicle bus reports loss of communication with smart EGR temperature sensor C. EGR cooling diagnostic switches to model-based estimation.

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

EGR temperature sensor C is a smart sensor that sends its temperature reading to vehicle modules over the communication bus. This code sets when the bus stops receiving sensor C messages, causing the EGR cooling diagnostic to use a modeled temperature estimate.

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. Save freeze-frame data and scan all modules for communication codes to find when sensor C went offline and whether other network faults occurred at the same time.
2. Locate EGR temperature sensor C using vehicle service information, then inspect its connector and harness for loose pins, corrosion, heat damage, or chafing.
3. Check the sensor module's power and ground according to the manufacturer's procedure.
4. Inspect the bus wires and splices serving sensor C for opens or shorts, and test them using the manufacturer's procedure.
5. If power, ground, and communication wiring are sound, use a capable scan tool to confirm sensor C is unresponsive before replacing its module.

Common fixes

• Reconnect or repair sensor C's connector and damaged terminals.
• Repair an open, short, or damaged splice in the sensor C communication wiring.
• Restore the sensor module's power or ground connection.
• Replace EGR temperature sensor C if it remains offline after circuit checks pass.

Can I keep driving?

If the vehicle runs normally, a short, gentle trip is generally reasonable, but avoid heavy loads if EGR or exhaust warnings appear. The missing sensor C input leaves EGR cooling checks estimated and may affect emissions control.