U069C

Code

Generic U — Network/User

Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 3

Brand: Generic

Type: U — Network/User

Views: UK: 19 EN: 28 RU: 24

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or shorted wiring between EGT sensor and control module
Corroded, loose or damaged connector at the sensor or module
Failed EGT sensor element or internal electronics
Harness/connector damage from heat, vibration or contaminants
Faulty control module or module input circuit
Bus/communication fault (if the sensor is networked via LIN/CAN)

Symptoms

Check Engine or MIL illuminated
Faults related to DPF regeneration, turbo control or emissions systems
Reduced performance or limp-home mode in some vehicles
Inability to complete DPF regeneration cycles
Stored freeze-frame data showing missing EGT readings for bank 2 sensor 3

What to check

Read full freeze frame and related stored codes; note ignition on/run state
Visually inspect sensor, connector and wiring for heat damage, soot, corrosion or disconnection
Check for other communication or module codes on the same network
Backprobe sensor connector and verify reference power, ground and signal presence (if applicable)
Perform continuity and resistance checks between sensor connector and control module connector
Wiggle test harness while monitoring live data to reproduce intermittent loss

Signal parameters

Passive thermocouple: millivolt output proportional to temperature (expect rising mV with temperature; open-circuit shows no mV)
Resistive/NTC sensor: resistance decreases/increases with temperature (compare to service specification)
Active sensors: may have a reference voltage (typically 5 V or vehicle-specific), ground and a signal output; check for stable reference and valid signal
Networked sensors: communication on LIN/CAN — verify bus voltage levels, bus activity and termination
Typical failure signatures: open circuit (OL or very high resistance), short to ground (near 0 V), short to battery (near reference battery voltage) or intermittent/no waveform

Diagnostic algorithm

Retrieve all codes and live data. Confirm U069C and check for related codes (EGT, CAN/LIN, module comms).
Visually inspect Bank 2 Sensor 3, its connector and wiring for damage, soot contamination, heat exposure, or loose pins.
With ignition ON (engine off), backprobe the sensor connector: verify reference power (if present), ground continuity and expected resting signal. Record voltages.
If sensor is passive thermocouple or resistive type, measure sensor output/resistance at the connector and compare cold/hot values to service limits. If open or out of range, suspect sensor or wiring.
Perform continuity and resistance checks between the sensor connector and the engine control/exhaust module connector. Look for shorts to ground or battery and for high resistance.
Wiggle the harness and connectors while monitoring live data or DTC status to identify intermittent faults.
If the sensor is on a communication bus (LIN/CAN), check bus voltage, termination and other nodes. Use a scope or scan tool capable of viewing bus traffic.
If wiring and bus check OK, swap with a known-good identical sensor (if possible) or temporarily bridge to a same-type sensor to confirm sensor vs module fault.
If replacement sensor fixes the issue, clear codes and perform a test drive/regeneration cycle as required. If fault persists after good sensor and wiring verified, consider module input driver fault and follow module diagnostics (or consult manufacturer service information).
After repair, clear codes and verify operation under conditions that previously set the fault.

Likely causes

Connector pinned out, corroded, or melted from heat near exhaust
Broken or chafed harness where it routes near exhaust components
Sensor failure caused by exposure to excessive heat or soot
Short to battery or ground at the sensor harness
Module input driver failed or internal module fault

Fault status

⚠️ Status

Lost communication or invalid/missing signal from Exhaust Gas Temperature Sensor — Bank 2 Sensor 3. Module cannot obtain usable temperature data from this sensor.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours