Precor TRM 885.v2 Service Manual page 63

Description
This error code monitors the physical lift position via a lift position potentiometer that
mechanically tracks the lift's physical position and sends a DC voltage back to the control
system. The voltage is converted to a 16 bit digital number. This number is then used to
determine the lift's physical position. Software sets upper and lower numerical limits. If the lift
position number is found to be outside of the set limits, error 42 will be displayed.
When troubleshooting an error 42 it is important to be aware of the actual physical position of the
lift when the error occurs. If the lift is physically out of range or jammed you must first determine
why the lift is physically out of range.
The A/D value for the home position (0%) is approximately 6800, and its A/D value at its lowest
incline (-3%) is approximately 4300.
Possible Cause

Lift motor drifted too low, less than -3%

Lift motor connector not seated correctly

Lift motor connectors backing out of the connector

Lift motor potentiometer faulted

Lift out of calibration
If the lift had been calibrated correctly at the time of installation and working for some
period of time it would be highly unlikely for lift calibration to go out of calibration on its
own. It would be more likely that something has broken causing the A/D value to be
wrong.
1.
Possible Remedies
1. If the incline has drifted down, enter diagnostics and navigate to the Lift or Incline test.
Attempt to drive the motor in the UP direction. If the lift does not move, remove the lift motor
from the lift platform and verify the lift tube is not jammed against the motor assembly.
2. Intermittent connections can be difficult to locate. If the error 42 condition is intermittent a
connection is almost certainly the problem. This is especially true if the error 42 occurs while
the lift is within its normal physical range.

Carefully inspect the lift potentiometer connector, repair the poor connection, if possible. If
the intermittent connection cannot be found or repaired, replace the lift motor.

An A/D number of 0 or 65535 indicates an open or shorted potentiometer connection. This
problem could be anywhere between the lift motor and the upper PCA. It can typically be
found and traced with an ohmmeter.

Set the treadmill's on/off switch in the off position. Remove the lift motor's connector from the
INCLINE connector on the Motor Controller. Visually inspect the lift motor's wiring and
connector for any broken or improperly crimped connections. With an ohmmeter, read
between terminals 3 (red) & 4 (black), 4 (black) & 8 (white) and 3 (red) & 8 (white) of the
INCLINE connector. Terminals 3 (red) & 4 (black) should read approximately 1kΩ (Ohms).
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