U023ENetwork · Lost communicationGeneric (SAE) code

U023E: Lost Communication With Front Distance Range Sensor - Right

Lost Communication With Front Distance Range Sensor - Right: the control module has detected this fault condition.

Typical labor cost
$125–$750 est.
1 h–6 h at an assumed $125/hr · parts extra · use your rate
Most common fix
Sensor unpowered or wiring broken
DIY difficulty: Hard · usually a shop job
01 —What it means

What U023E means

U023E is a generic OBD-II network code in the lost communication group. In plain English: a control module stopped receiving messages from the Front Distance Range Sensor - Right on the vehicle’s data network.

U
Network
0
Generic (SAE)
2
Subsystem group
3E
Specific fault
How to read U023E. We group it under Lost communication.
Check engine light
Usually on
Emissions-related
No
Limp mode possible
Yes
Drive cycle to clear
Required
Code data: OBDex (CC0)

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02 —Symptoms

Symptoms

What drivers typically notice
  • 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
Code data: OBDex (CC0)
03 —Causes

Common causes

Ranked from most to least likely
  1. 01Sensor unpowered or wiring brokenMost likely
  2. 02Gateway module routing CAN messages incorrectlyLess likely
  3. 03CAN terminating resistor (120 Ω) drifted out of specLess likely
Code data: OBDex (CC0)
04 —Severity

Can I drive with U023E?

Urgent

Not recommended beyond getting it to a shop.

This fault can put the engine or transmission in limp mode with reduced power, which can make merging and passing unsafe. Have it diagnosed as soon as possible.

Why we rate it urgent

  • Can put the vehicle in limp mode (reduced power)
  • Turns on the check engine light
  • Needs a drive cycle to confirm a repair

Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.

Code data: OBDex (CC0)
05 —Diagnosis

How to diagnose U023E

General procedure — follow the service manual for your vehicle
  1. 1

    Confirm the code and save freeze-frame data

    Read the codes with an OBD-II scan tool and note every code, not just U023E. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.

  2. 2

    Fix other faults first

    If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.

  3. 3

    Check module power, ground and the data bus

    Confirm the module named in the code has battery voltage, ignition feed and a good ground. With the battery disconnected, a healthy CAN bus usually measures about 60 ohms between CAN-High and CAN-Low at the OBD port. Inspect connectors for corrosion and pushed-out pins.

  4. 4

    Test the likely causes in order

    Start with the most likely cause and work down: Sensor unpowered or wiring broken; gateway module routing CAN messages incorrectly; CAN terminating resistor (120 Ω) drifted out of spec. Test before replacing parts.

  5. 5

    Check for recalls and service bulletins

    Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.

  6. 6

    Clear the code and verify the repair

    After the repair, clear the code and complete a full drive cycle (cold start, idle, steady highway cruise, deceleration). The code is fixed when the related readiness monitor completes without it returning.

Code data: OBDex (CC0)
06 —Cost

U023E repair cost estimate

Labor only — set your local shop rate
Labor estimate for U023E
$125–$750
1 h–6 h of labor × $125/hr (assumed rate) · parts extra

Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.

DIY difficulty
Hard
Good DIY job?
Usually a shop job

Involved testing or major parts. Most owners use a shop.

Code data: OBDex (CC0)
07 —Components

Parts and systems involved

  • Front distance sensor R
  • CAN bus
Code data: OBDex (CC0)
09 —FAQ

U023E FAQ

What does U023E mean?

U023E means “Lost Communication With Front Distance Range Sensor - Right”. Lost Communication With Front Distance Range Sensor - Right: the control module has detected this fault condition.

Is U023E serious? Can I keep driving?

We rate U023E as urgent severity. Not recommended beyond getting it to a shop. This fault can put the engine or transmission in limp mode with reduced power, which can make merging and passing unsafe. Have it diagnosed as soon as possible.

What causes U023E?

The most common causes, from most to least likely: Sensor unpowered or wiring broken; Gateway module routing CAN messages incorrectly; CAN terminating resistor (120 Ω) drifted out of spec. Test before replacing parts, because several causes can set the same code.

How much does it cost to fix U023E?

Typical labor is about $125–$750 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.

Can I fix U023E myself?

DIY difficulty is hard. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.

Will U023E clear itself?

Once the fault is fixed, the check engine light usually goes off by itself after the system passes its self-test over several drive cycles. Clearing the code with a scan tool resets readiness monitors, so an inspection station may turn you away until a full drive cycle is completed.

Code data: OBDex (CC0)