U068F

Code

Generic U — Network/User

Lost Communication With EGR Temperature Sensor C

Brand: Generic

Type: U — Network/User

Views: UK: 16 EN: 21 RU: 16

AI status

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Page language: EN

Causes

Open or short in sensor wiring harness (power, ground, signal)
Corroded, loose or damaged connector at the EGR temperature sensor
Failed EGR temperature sensor (internal open/short)
Poor or missing sensor power or ground supply
Intermittent wiring damage (chafing, pinched, broken wires)
Faulty control module or module software/firmware issue

Symptoms

Malfunction Indicator Lamp (MIL) or check engine light illuminated
Possible reduced engine performance or limp-home behavior if EGR is disabled
Increased NOx or failed emissions readiness
EGR system deactivated or fault message displayed
Intermittent or persistent diagnostic trouble codes related to EGR or communications

What to check

Retrieve freeze frame and full DTC list with a factory-level scan tool; note when code set and any related codes
Visually inspect sensor, connector, and wiring harness for damage, corrosion, pins pushed out, or water intrusion
Verify connector is fully seated and locking tab engaged
Check related fuses and power distribution for sensor supply circuits
Backprobe sensor connector to check power and ground presence with key on/engine off
Use a scan tool to monitor EGR temperature data stream; note if value is absent, static, or intermittent

Signal parameters

EGR temperature sensors are typically NTC thermistors: resistance decreases as temperature rises (consult OEM spec for exact resistance vs. temperature curve)
Typical sensor signal is a variable voltage within 0.5–4.5 V range when referenced to an ECM analog input (vehicle-specific — verify service data)
Sensor update rate: control module expects regular updates (usually multiple times per second); a missing or frozen value indicates communication loss
Expected continuity: signal and ground circuits should show low resistance to the PCM connector when disconnected from PCM (open if broken)
If sensor is a digital device (CAN/SPI/etc.), the control module expects valid packet messages at the bus interval used by the vehicle (check bus activity with a scan tool or oscilloscope)

Diagnostic algorithm

Retrieve all stored codes and freeze frame data. Note any other communication or EGR-related codes.
Perform a visual inspection of the EGR temperature sensor C, connector, and wiring. Repair obvious damage or corrosion.
With ignition ON (engine OFF), backprobe the sensor connector: verify reference power (if applicable), ground, and signal voltage. Compare to expected values in service data.
Monitor EGR temperature data with a scan tool while warming engine or applying heat to sensor to confirm the sensor reading changes. If data does not appear in the scanner, suspect communication or sensor failure.
If no power/ground at the sensor, trace and repair circuit (check fuses, relays, fusible links).
If power/ground present but no signal or constant/frozen value, remove sensor and measure its resistance vs. temperature (or voltage if applicable) against OEM spec or a known-good sensor. Replace sensor if out of spec.
Perform continuity test from sensor connector to PCM connector for signal and ground. Repair any opens/shorts. Check for high resistance connections.
If wiring and sensor test good but control module does not receive data, check vehicle communication bus (if sensor is networked). Use an oscilloscope or advanced scan tool to check bus activity and message integrity.
After repairs, clear codes, perform a test drive and re-scan to confirm the code does not return and that EGR temperature data is present and plausible.
If fault persists after verifying sensor and harness, consider module reflash/repair or replacement following OEM diagnostics.

Likely causes

Damaged or corroded connector at the EGR temperature sensor
Open/short in sensor signal or ground wiring from sensor to PCM
Failed EGR temperature sensor element
Intermittent wiring failure aggravated by vibration or engine movement
Module not receiving sensor due to bus/module fault (less common than wiring/sensor)

Fault status

⚠️ Status

Lost communication with EGR temperature sensor C — control module not receiving valid temperature data or messages from that sensor circuit.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours

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