Precor Error Code 18 Dynamic Brake Resistor (DBR) Thermal Switch Open

Feb 21, 2022

Applies to TRM800-14/18 treadmills

Issue symptoms

As with Error 17, current generated by the drive motor is sent to the dynamic brake resistor (DBR). If enough current is sent to the dynamic brake resistor (DBR) such that it becomes excessively warm, an internal thermal switch will open, which will stop the treadmill and briefly display Error 18. This error will be logged and “Use Another Treadmill” will be displayed if the dynamic brake resistor (DBR) thermal switch connector is not plugged in, or if the dynamic brake resistor (DBR) has reached its thermal upper limit.

Troubleshooting steps

1. Verify that the dynamic brake resistor (DBR) thermal switch is properly seated into the connector (it can be wedged into the connector opening without being properly seated).
2. Verify that the dynamic brake resistor (DBR) temperature. If it is stuck ON, it may be hot. If stuck ON and it is not hot, replace both the Motor Controller and dynamic brake resistor (DBR).
3. Unplug all connections from the dynamic brake resistor (DBR) and check resistance of the DB thermal switch (smaller black connector). If 10Ω or greater, replace the dynamic brake resistor (DBR).

Note: Use care to only touch the multimeter probes to the connector contacts. DO NOT push the probe tips into the contacts. Doing so may damage the contacts.