U0156
Lost Communication With Information Center "A"
- Severity
- Low
- Driving
- No driving restriction
The control module has stopped receiving messages from information centre "A". The feature it provides is unavailable. Nothing about the way the car drives or stops is affected, and this can wait until it is convenient - though it is worth fixing rather than ignoring, because the underlying cause is often a power, earth or bus problem that will eventually affect something that does matter.
Possible causes
- CommonLow battery voltage or a discharged battery, dropping modules off the bus
- CommonBlown fuse or corroded earth on the supply to information centre "A"
- CommonConnector disturbed during stereo, dashboard or trim work
- CommonAftermarket head unit or amplifier fitted without the correct interface
- PossibleDamaged, chafed or corroded bus wiring
- PossibleFailed module
- PossibleModule not coded to the vehicle after replacement
What you might notice
- The feature is dead or unresponsive
- Display blank or frozen
- No sound, or sound from some speakers only
- System restarting repeatedly
- Occasionally a battery drain, if a module will not go to sleep
What to check, in order
- Check battery voltage and state of charge before anything else. A weak or failing battery drops modules off the bus and sets lost-communication codes with no wiring fault at all - this is the single most common false lead in this whole family.
- Ask whether an aftermarket stereo or amplifier has been fitted. Replacing a factory head unit that sits on the vehicle bus, without the proper interface, is one of the most common causes of these codes - and of a battery that goes flat when the car is parked.
- Check the fuses and earths for information centre "A".
- Check whether the connector was disturbed during recent trim, dashboard or stereo work.
- Note how many U-codes are stored. Several at once points at battery, earth or bus wiring rather than at several failed modules.
- If the car also has an unexplained battery drain, investigate this code rather than dismissing it. A module that cannot communicate may also fail to go to sleep.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
U00xxU01xxU02xxU03xxU04xxU05xxU06xxU07xxU08xxU09xxU0AxxU0BxxU0CxxU0DxxU0ExxU0FxxU10xxU11xxU12xxU13xxU14xxU15xxU16xxU17xxU18xxU19xxU1AxxU1BxxU1CxxU1DxxU1ExxU1FxxU20xxU21xxU22xxU23xxU24xxU25xxU26xxU27xxU28xxU29xxU2AxxU2BxxU2CxxU2DxxU2ExxU2FxxU30xxU31xxU32xxU33xxU34xxU35xxU36xxU37xxU38xxU39xxU3AxxU3BxxU3CxxU3DxxU3ExxU3Fxx
Network communication
U0100U0101U0102U0103U0104U0105U0106U0107U0108U0109U0110U0111U0112U0113U0114U0115U0116U0117U0118U0119U0120U0121U0122U0123U0124U0125U0126U0127U0128U0129U0130U0131U0132U0133U0134U0135U0136U0137U0138U0139U0140U0141U0142U0143U0144U0145U0146U0147U0148U0149U0150U0151U0152U0153U0154U0155U0156U0157U0158U0159U0160U0161U0162U0163U0164U0165U0166U0167U0168U0169U0170U0171U0172U0173U0174U0175U0176U0177U0178U0179U0180U0181U0182U0183U0184U0185U0186U0187U0188U0189U0190U0191U0192U0193U0194U0195U0196U0197U0198U0199