U0157: Lost Communication With Information Centre B
What to do
A second screen in the car has gone blank, and the car is entirely safe to drive.
There is one free check worth doing before it goes anywhere, and it will genuinely narrow things down.
Is the other display still working?
If it is, then the information is reaching the car perfectly well and only that one screen has a problem — its power supply or its connection. That is a much smaller job.
If both are blank, the fault is further back — something feeding both of them — and replacing either screen would be a waste of money.
Tell the garage which of the two you found. It saves them an hour and you the cost of it.
If your vehicle is a van, minibus or motorhome and the second screen is for body equipment, contact whoever converted it first. That wiring is usually theirs, and the fault is normally where their harness meets the vehicle's.
What this code means
A second information display has stopped being heard from. See U0156 for why a blank display is the honest failure, and U0458 for what a second one usually is.
Where two displays exist, silence localises the fault immediately in a way that bad data does not — and the check is free.
U0458's test is whether two working screens agree. Here the test is simpler: which one is blank?
- One blank, the other working. The fault is that display, its supply or its connection. The information reaching the vehicle is fine, because the other screen is showing it — which rules out every module that supplies the data and narrows the search to one unit.
- Both blank. The fault is upstream of both: a shared supply, the gateway between them and the rest of the vehicle, or the network itself. Replacing either display is wasted money.
That distinction is worth making before the vehicle goes anywhere, because it is the difference between a connector and a network investigation.
On a converted or commercial vehicle there is a further possibility worth eliminating first. A second display fitted for body equipment or fleet use is often the converter's work rather than the manufacturer's, so the join between the two harnesses is where the fault lives — the U0148 argument.
Everything else at U0156 applies, including the warning about second-hand display modules and stored mileage.
Likely causes
Start here
- Blown fuse or failed supply · easy
- Corroded or loose connector · easy
- Damaged data bus wiring · moderate
Less common
- Poor wiring splice in an aftermarket installation · moderate
- Module not coded to the vehicle · specialist
- Failed power or earth supply to the module · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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