OBD-II Diagnostic Trouble Code
U0156 — Lost Communication With Information Center A
U0156 means the network lost communication with Information Center A, the driver information display module or message center. Other modules stopped receiving its messages within the allowed time. On many trucks this display is built into the instrument cluster, while on others it is a separate module.
Severity 2/5
Truck-relevant
Service soon
Severity
Service soon
Lost Communication With Information Center A
Code
U0156
Category
Network
Subsystem
Network
Truck-relevant
Yes
What this means for truckers
U0156 (Lost Communication With Information Center A) — info display offline.
Before you replace parts — try this first
U0156 on the Network system is most often power, fuse or ground fault at the information display — 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
The driver information display is blank or frozen, and driver messages, trip data or menus are unavailable. Other U-codes may appear if a shared network problem is present. Driveability is normally not affected.
Common causes
- CommonPower, fuse or ground fault at the information display ($50–$250)
- CommonLoose connector or damaged network wiring behind the dash ($150–$500)
- OccasionalFailed information center or display module ($300–$1500)
How to fix
Check fuses, power and grounds to the display module
When to use: First step
Inspect connectors and test the network wiring to the display
When to use: When power is good
Replace or repair the information center and program it if required
When to use: After the wiring has been verified
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
- → U0100 — Lost Communication With ECM/PCM A
- → U0101 — Lost Communication With TCM
- → U0102 — Lost Communication With Transfer Case Control Module
- → U0103 — Lost Communication With Gear Shift Module
- → U0104 — Lost Communication With Cruise Control Module
Frequently Asked Questions
Can I drive with code U0156?
U0156 is severity 2 — service this week. Not an immediate stop, but ignoring it usually compounds the problem. Most common cause for this code is a worn sensor or minor performance fault that won't strand you today but will get more expensive the longer you wait.
How much does it cost to fix U0156 on a commercial truck?
Total repair cost ranges $50–$1500 depending on the root cause. The cheapest fix is usually the first one listed below — Power, fuse or ground fault at the information display — 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 U0156 fail a DOT inspection?
U0156 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 U0156 and related codes?
U0156 is closely related to: U0100 (Lost Communication With ECM/PCM A), U0101 (Lost Communication With TCM), U0102 (Lost Communication With Transfer Case Control Module), U0103 (Lost Communication With Gear Shift Module). 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 U0156 is set without the companions, the issue is more isolated.
How do I prevent U0156 from coming back after a repair?
For U0156 (Lost Communication With Information Center A), 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.