Fault Phenomenon: Shantui DH52 accelerates normally when cold. After reaching operating temperature (high engine compartment temperature), acceleration response is sluggish, RPM only reaches 1500, and the condition worsens.

Troubleshooting Process:
– Checked electronic throttle actuator: no mechanical sticking.
– Checked intake manifold pressure sensor: reading normal, no drift.
– Checked ECU power supply and ground wire: resistance normal when cold.
– Measured ground wire resistance at operating temperature: found resistance increases as temperature rises.

Root Cause: The engine compartment main wiring harness ground point is corroded, causing poor contact due to thermal expansion.

Required Parts: Engine wiring harness and ground point repair treatment.