OBD-II Diagnostic Trouble Code
U0235 — Lost Communication With Cruise Control Front Distance Range Sensor
U0235 sets when modules stop receiving messages from the front distance range sensor used for adaptive cruise control and collision mitigation, usually a forward radar unit. The engine controller, brake controller or cluster expected distance data and did not receive it within the allowed time. On heavy trucks this is typically the collision mitigation radar mounted in the bumper.
Severity 3/5
Truck-relevant
Service this week
Severity
Service this week
Lost Communication With Cruise Control Front Distance Range Sensor
Code
U0235
Category
Network
Subsystem
Network
Truck-relevant
Yes
What this means for truckers
U0235 (Lost Communication With Cruise Control Front Distance Range Sensor) — adaptive cruise/forward collision sensor offline.
Before you replace parts — try this first
U0235 on the Network system is most often fuse, power or ground fault at the radar sensor — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Adaptive cruise and collision warning or mitigation are disabled with a warning on the cluster, and cruise control may drop to standard mode or not work at all. Automatic emergency braking will not work. The truck otherwise drives normally.
Common causes
- CommonFuse, power or ground fault at the radar sensor ($50–$250)
- CommonCorroded connector or damaged wiring at the bumper-mounted sensor ($150–$600)
- OccasionalSensor damaged by front-end impact ($1000–$3500)
- OccasionalInternal radar sensor failure ($1000–$3500)
How to fix
Check fuses, power and grounds to the radar sensor
When to use: First step
Inspect the bumper harness and connector for corrosion, impact damage or chafing, and test network circuits
When to use: When power is good
Replace the radar sensor and perform alignment and calibration with the manufacturer's software
When to use: When the sensor is damaged or still will not communicate with good wiring
Verify adaptive cruise operation on a road test
When to use: After the repair and calibration
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
Frequently Asked Questions
Can I drive with code U0235?
U0235 is severity 3 — plan service within a few days. Performance is likely degraded already (you may feel reduced power, harsher shifts, or slightly worse fuel economy). Continuing to drive risks additional damage to adjacent components.
How much does it cost to fix U0235 on a commercial truck?
Total repair cost ranges $50–$3500 depending on the root cause. The cheapest fix is usually the first one listed below — Fuse, power or ground fault at the radar sensor — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will U0235 fail a DOT inspection?
U0235 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between U0235 and related codes?
U0235 is closely related to: U0214 (Lost Communication With Remote Function Actuation), U0293 (Lost Communication With Hybrid Vehicle Control System), U0294 (Hybrid Vehicle Control System Internal Performance). These codes share the same subsystem (network) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only U0235 is set without the companions, the issue is more isolated.
How do I prevent U0235 from coming back after a repair?
For U0235 (Lost Communication With Cruise Control Front Distance Range Sensor), prevention centers on the network system. Pay attention to ground connections at every PM — bad grounds are 70% of communication codes. Inspect harness routing for chafe points. Don't disconnect modules with the key on.