GM
Type:
    Powertrain - Manufacturer Controlled DTC - Manufacturer Controlled
Description:
    Internal Mode Switch Circuit 'A' Low (4T80-E Transmission)
Cause:
    Engine runtime over 5 seconds, system voltage from 8-18v, Fuel Cutoff inactive, engine torque from 30-148 ft-lb (40-200 Nm), then the PCM detected that the IMS signal indicated PARK for 2 seconds and then the IMS indicated a transitional state between D4 and D3, conditions met for 5 seconds.