Cluster not on the bus — usually clocks go blank.
U0155 — also written UO155, U 0155, 0155 — is the OBD-II code for lost communication with instrument cluster. Same code, same fix: this page covers every spelling of it.
Lost communication with instrument cluster — the ECU can't see the dash on the CAN bus, so the clocks may go blank, the speedo may freeze, or the whole panel flickers. Usually a failed cluster, a corroded CAN wire connector, or a body-control-module fault that's pulling the CAN bus down. It's an MOT concern because a non-functional speedometer is an automatic fail.
U0155 is a electrical fault code, typically costing £100–£900 to put right in a UK garage.
What U0155 actually feels like to drive
- Speedo drops to zero while driving then comes back
- Whole dash goes blank on ignition — no warning lights, no needles
- Random illumination of ABS, airbag, and traction lights together
- Central locking or indicators occasionally stop working alongside
- Paired codes: U0100 (lost comms with ECM), U0121 (ABS), U0140 (BCM)
What causes U0155?
- Failed cluster
- CAN wiring fault
- Cluster power fault
UK vehicles that throw U0155 most often
- Ford Focus / Fiesta / Kuga (2011 onwards)
- Vauxhall Corsa D/E, Astra J, Insignia — cluster ribbon-cable fault
- Renault Clio / Megane / Captur / Kadjar — BSI faults common
- VW Polo / Golf / Passat, Audi A3 / A4 — CAN gateway issues
- Nissan Qashqai / Juke / Micra — cluster power supply fault
- Peugeot 208 / 308 / Citroën C3 / C4 — BSI (Body Systems Interface) faults
How U0155 is fixed
- Test cluster power
- Repair CAN wires
- Replace cluster
The U0155 misdiagnosis that wastes money
First move — measure cluster power and ground with a multimeter. If either is missing or drops under load, you've got a wiring/fuse fault and a new cluster won't fix it. Second move — check the CAN-High and CAN-Low resistance across the diagnostic port with the ignition off (should be 60 ohms). If it reads 120 ohms one of the two 120-ohm terminating resistors (usually in the ECM and the cluster) is out of circuit; if it reads under 30 ohms you've got a short. Third — inspect the connectors behind the cluster and at the CAN-gateway module for corrosion; on Vauxhall Corsa D water gets in via the windscreen scuttle and rots the loom. Only after all that does a cluster replacement make sense — and on most makes a replacement cluster needs coding to the car (mileage match, VIN, keys) which is a specialist job.
What a UK garage should charge for U0155
Diagnostic + CAN network test £60–£120, connector/loom repair £45–£180, replacement instrument cluster £180–£520 aftermarket / £320–£950 OEM, cluster coding + mileage-write £80–£180 specialist. On Renault/Peugeot/Citroën BSI faults, BSI module + coding £280–£680. Labour From £70/hr.
U0155 repair cost in the UK
Most U0155 repairs land between £100–£900 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on U0155
On Vauxhall Corsa D the classic 'random dash blackout' is nearly always the earth strap on the top of the gearbox corroding — clean it, add dielectric grease, done, £0 in parts. On Ford Focus MK3 the cluster ribbon cable inside the panel cracks and can be reflowed by a mobile auto-electronics specialist for around £120 (versus £480 for a new cluster). On Renault/Peugeot 'BSI' is a repair job for a specialist, not a garage — the module needs cloning to keep your keys. If your speedo is intermittent get it fixed before your next MOT — no working speedometer is an automatic fail and you can't just plate over it. <a href="/ask-a-mechanic-uk?code=U0155">Ask Bob about your U0155</a> for £14.99 with make, model, mileage and whether the fault is intermittent or permanent — you'll know whether it's a £5 earth strap, a £120 ribbon repair or a full cluster.
Can you drive with U0155?
Yes but no speedo — MOT risk.
Urgency: medium.