Fault Phenomenon: Zoomlion ZLJ5500THB GPS functions normally when cold. With the antenna under direct sunlight (operating temperature), the GPS goes offline, location does not update, and monitoring fails.

Troubleshooting Process:
– Checked SIM card: card contact good.
– Checked antenna connection: connection secure.
– Checked host power supply: supply stable.
– Measured antenna module temperature at operating temperature: found temperature too high.

Root Cause: The GPS antenna module’s performance degrades due to heat, causing signal reception failure.

Required Parts: GPS antenna and host module.