OBD-II Diagnostic Trouble Code
U0010 — Medium Speed CAN Communication Bus
U0010 means a control module detected a fault on the Medium Speed CAN (MS-CAN) communication bus, a slower network typically used for body, cluster and comfort modules. The module setting the code saw missing, corrupted or inconsistent messages on that bus as a whole rather than a single module dropping out. Exact bus assignment varies by manufacturer, so the OEM network diagram defines which modules share it.
Severity 3/5
Truck-relevant
Service this week
Severity
Service this week
Medium Speed CAN Communication Bus
Code
U0010
Category
Network
Subsystem
Network
Truck-relevant
Yes
What this means for truckers
U0010 (Medium Speed CAN Communication Bus) — secondary CAN bus fault. Same diagnostic as U0001 but on the slower bus that handles body/comfort systems.
Before you replace parts — try this first
U0010 on the Network system is most often chafed, corroded or water-intruded ms-can wiring or a loose connector at a module — 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
Often only a warning light with several U-codes stored in other modules. Gauges, door locks, HVAC controls, radio or cluster warnings may act erratically or go dead, while the engine usually runs normally. On some medium-duty trucks the scan tool cannot reach modules on that bus.
Common causes
- CommonChafed, corroded or water-intruded MS-CAN wiring or a loose connector at a module ($150–$700)
- CommonLow battery voltage, poor chassis grounds or charging problems corrupting bus traffic ($100–$500)
- OccasionalOne failed module shorting or loading down the bus ($400–$1800)
- OccasionalMissing or open terminating resistor on the MS-CAN bus ($100–$400)
- RareAftermarket device (telematics, ELD, remote start) spliced into the bus ($75–$300)
How to fix
Check batteries, charging voltage and main grounds, then clear codes and recheck
When to use: First step whenever several network codes appear together
Measure resistance between MS-CAN high and low at an accessible bus connector with the key off (about 60 ohms with both terminators present)
When to use: To confirm whether the bus wiring or terminators are open or shorted
Unplug modules on the bus one at a time while watching bus voltage or communication
When to use: When a short or bus-loading fault is suspected
Inspect and repair harness sections near frame rails, firewall pass-throughs and cab mounts
When to use: When the fault is intermittent or tied to bumps, rain or washing
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → U0001 — High Speed CAN Communication Bus
- → U0002 — High Speed CAN Communication Bus Performance
- → U0019 — Medium Speed CAN Communication Bus B
- → U0073 — Control Module Communication Bus Off
- → U007A — Control Module Communication Bus H Off
Frequently Asked Questions
Can I drive with code U0010?
U0010 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 U0010 on a commercial truck?
Total repair cost ranges $75–$1800 depending on the root cause. The cheapest fix is usually the first one listed below — Chafed, corroded or water-intruded MS-CAN wiring or a loose connector at a module — 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 U0010 fail a DOT inspection?
U0010 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 U0010 and related codes?
U0010 is closely related to: U0001 (High Speed CAN Communication Bus), U0002 (High Speed CAN Communication Bus Performance), U0019 (Medium Speed CAN Communication Bus B), U0073 (Control Module Communication Bus Off). 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 U0010 is set without the companions, the issue is more isolated.
How do I prevent U0010 from coming back after a repair?
For U0010 (Medium Speed CAN Communication Bus), 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.