U0155 Howo — no IPC on CAN, causes and repair

Fault codes / U0155

U0155 is SAE lost communication with the IPC. Dead cluster or a live cluster that peers cannot hear. On Howo A7 the field point is the X201 20-pin under the dash. Not U0100 (ECM) and not U0101 (TCM). No cluster OEM in our card.

Which trucks see it

Howo A7/T7H, Shacman, Sitrak C7H. Cab flex on Sitrak often kills the same CAN as U0100.

Symptoms

• dark cluster
• dead speedo with engine running
• scanner cannot see IPC
• after dash removal or cab tilt

Likely causes

• X201 20-pin on Howo A7 — pins and latch.
• CAN not ~60 Ω key off.
• Cluster power/ground/fuse. No OEM in the card.

What to check

1. Power and ground first.
2. Reseat X201 on A7.
3. 60 Ω CAN. If P0562 is next, fix 24 V first.

Can you keep driving

Drive if the engine and brakes are fine and you can see speed another way. Do not night-run a dark cluster. Home form: code or photo.

Look up the code in the service

Other codes

• P0087 — low common-rail pressure
• P0088 — high common-rail pressure
• P1011 — HP pump metering valve fault
• P0093 — large fuel leak / CAN trap — FMI needed
• P0193 — rail pressure sensor high signal
• P0299 — boost below target
• P2263 — turbo / boost performance
• P2563 — VGT position sensor — range / performance
• P0335 — crankshaft sensor no signal
• P0340 — camshaft sensor (CMP) — FMI needed
• P0401 — EGR insufficient flow
• U0100 — lost communication with engine ECU
• U0101 — lost communication with TCM
• P0562 — system voltage low
• P0201 — cylinder 1 injector circuit
• P0480 — fan control circuit
• P0217 — engine overheat
• P0116 — water in fuel (Weichai table) / not always coolant SAE
• P2509 — intermittent ECM power (no OEM in DB)
• SPN 2898 — without FMI — not a diagnosis (config / Weichai grid)
• SPN 729 — intake heater — FMI needed