Page
7 of 8
Owners Manual
5. Wiring Instructions (Continued)
Remote Driver’s LED Display
The LED display includes a 36 inch cable that is attached to the underside of the display at one end and contains
a 6-pin connector plug at the other end. Mount the display in a suitable location on the dash (usually to the right of
the steering wheel). Two methods may be used for routing the cable. It may exit the side of the display so that it
can be routed between the dash panel and the steering column. Or, you can drill a hole in the dash so that the
cable can be routed through and behind the dash. Attach the display with the to mounting screws provided, route
the cable to the ITM131 control module, and insert the cable plug into connector J2.
NOTE - Consult GM documentation before drilling to verify the location of all critical components and
harnesses.
6. Interlock System Operation
The interlock system is powered from the Interlock Power Switch and the Ignition Switch when they are both in the
On position. The following is the interlock system sequence of operation:
Step 1 - With the interlock powered on, place the transmission in the Park position.
Step 2 - Set the parking brake.
Step 3 - Open the lift door. When opened, the transmission shift lock will be set to prevent the transmission
from being taken out of Park, and the Lift Enable will be set to allow operation of the platform lift. The
Lift Door Open light, if installed, will operate.
Step 4 - The platform lift may now be operated (Refer to the platform lift operating instructions). Note - During
the Lift Enable sequence, if the parking brake is released the Lift Enable will be deactivated,
preventing lift operation.
Step 5 - When the lift cycle is completed return the lift to its fully stowed position.
Step 6 - Close the lift door.
Step 7 - Release the parking brake. When released, the shift lock will be automatically released.
Step 8 - The cycle is now complete and the vehicle can be taken out of Park and driven.
Notes:
1. The Lift Door Open output (+12 v @ 10 amps) is activated whenever the door is open, independent of
other interlock inputs.
7. System Troubleshooting
If there is a problem with system operation, there is a very high probability that the control module has: A) either
lost its ground or +12 volt power source, or B) that one or more of its inputs are not being actuated by a remote
switch (e.g., Lift Door Switch or Lift Stowed Switch). Most troubles are related to wiring problems, or switches
either failing or becoming out of adjustment.
Troubleshooting Procedure:
Step 1 - Determine if the control module is powered. If the LEDs on the control module are illuminated you have
power. If none are illuminated, check the +12 volt supply on +12V terminal with a voltmeter. Also
check that the module is getting a good ground on the GND terminal.
Step 2 - If the ground and power are correct, first reset the interlock system by turning off its power. Then, step
through the operating sequence as described in Section 6. Interlock System Operation, and note the
status of the green and red LED indicators on the ITM131 control module. Pay particular attention to
the inputs (Green LEDs) such as the lift door switch input and the lift stowed switch input. Verify that
The input status LEDs agree with the switch positions.
The ITM131 interlock module contains six diagnostic LED indicators to aid in system troubleshooting. These
indicators show the status of input and output signals of the ITM131 control module, and are color coded as
follows: Input Signals = Green and Output Signals = Red. These diagnostic indicators are located on the
connector side of the module.
Document: OM-66
Date: Sept. 25, 2007
Version Code: C
Date: Dec 29, 2022
InPower LLC
8311 Green Meadows Drive
Lewis Center, Ohio 43035 USA
740-548-0965
www.InPowerLLC.com
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