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Decoder Module

  1. Place ignition switch in "RUN" position. Probe decoder module terminals and measure voltage to ground. See DECODER MODULE INPUT VOLTAGES table. Put gear selector switch in positions indicated. Switch positions not listed should have zero volts.
    DECODER MODULE INPUT VOLTAGES

    Terminal (Wire Color) Voltage Gear Position
    White/Black Battery All
    Dark Blue Battery All
    Black/White Battery P, R, D, 2
    Yellow Battery R, N, D, D
    Gray Battery D, D, 2, 1
    White Battery P, N, D, 1
  2. If voltage at a terminal is not correct, check wire or switch connected to that terminal. Make sure that Black and Black/White wire terminals are grounded. If they are not grounded, locate and repair open circuit.
  3. Probe decoder module again and measure voltages to ground. See DECODER MODULE OUTPUT VOLTAGES table. Voltage should be less than one volt in positions not listed. If any output voltage is incorrect, check affected circuit for shorts to ground. If no short is found, replace decoder module.
DECODER MODULE OUTPUT VOLTAGES

Terminal (Wire Color) Voltage Gear Position
Lt. Green/Black Battery P
Dk. Blue/White 1.9-1.95 All
Light Green Battery R
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