U0156: Lost Communication With Information Center "A"
Other control units no longer receive messages from the Information Center A.
Normal risk
Have it checked soon. Messages and displays on the dashboard may be missing.
Short answer · Can I keep driving with U0156?
Usually yes, with care. Messages and displays on the dashboard may be missing. Have the network and the module checked soon.
What does U0156 mean?
Code U0156 means a control unit expected regular messages from the Information Center "A" on the vehicle network and they stopped arriving. A power or ground fault at that module, a damaged network wire or corroded connector, low battery voltage or a failed module are typical causes.
What the car does when the code is set
Functions of the affected module may stop working or behave strangely, for example lights, locks, climate control, displays or the radio.
How the system works
Body functions such as lights, locks, displays, climate control and audio are handled by modules on the body network. A gateway often links this network to others. Missing messages from one module are stored as lost communication codes in the others.
Common symptoms
Possible causes
Listed without ranking. The cause on your car depends on make, engine and mileage — see the maker notes below.
- Power or ground fault at the moduleA blown fuse or poor ground.
- Network wiring faultDamaged or corroded wires and connectors.
- Low battery voltageCommon after the car has stood for a long time.
- Aftermarket equipmentAccessories connected to the body network can disturb it.
- Failed modulePossible, but check the basics first.
How it is diagnosed
- Check which functions do not workLights, locks, dashboard displays or climate control point to the module concerned.
- Check fuses and battery voltageUse the fuse diagram for the module.
- Look for water entryWet carpets, door seals and sunroof drains often explain corroded body modules.
- Scan all modulesA workshop checks whether the module responds and tests the network.
Questions about U0156
Can a weak battery cause U0156?
Yes. Low voltage during starting can make modules drop off the network for a moment and store this code. Check the battery before replacing any module.
Is a body network code dangerous?
Usually not for driving, unless lights, wipers or other safety functions stop working.