P0201 Howo — cylinder 1 injector circuit, causes and repair

Fault codes / P0201

Open, short or ECU driver on injector 1. Misfire and smoke. P0202–P0206 are the other holes. This is the electrical circuit, not just a leaking nozzle.

Which trucks see it

WP10–WP13 and WD615 on Howo/Shacman. Loom at the valve cover rubs through.

Symptoms

• idle misfire
• raw diesel smell
• code stuck on one cylinder

Likely causes

• Open at injector 1 plug.
• Failed solenoid.
• ECU driver — after loom and coil check.

What to check

1. Swap plugs with the neighbour.
2. Resistance and short to body.
3. Valve-cover boot.
4. Do not buy a full set while the code follows the plug.

Can you keep driving

Unloaded limp if it is not hammering. Heavy smoke — park it.

Look up the code in the service

Other codes

• P0087 — low common-rail pressure
• P0193 — rail pressure sensor high signal
• P0299 — boost below target
• P0335 — crankshaft sensor no signal
• P0401 — EGR insufficient flow
• U0100 — lost communication with engine ECU
• P0562 — system voltage low
• P0116 — water in fuel (Weichai table) / not always coolant SAE
• P2509 — intermittent ECM power (no OEM in DB)