Advanced Diagnostics

Advanced Diagnostics - DTC P0706: Open in Transmission Range Switch Circuit










General Description
The transmission range switch is attached to a control shaft. Operating the shift lever makes the control shaft rotate via the shift cable. The A/T gear position indicator shows which position is selected according to the Low/High signal combinations, which vary based on the control shaft rotational angle. The control shaft changes the position of the transmission range switch, activates the manual valve, and switches hydraulic pressure to shift the transmission through forward/neutral/reverse. The transmission range switch signal is used to determine the shift schedule. The voltage is high (5 V or 12 V) at the powertrain control module (PCM) input terminal when each transmission range switch position is open, and it is low (0 V) when each switch is closed. If the FWD position signal stays open while the vehicle repeatedly accelerates to a specified vehicle speed and then stops despite being in D or S, the PCM detects a malfunction in the transmission range switch (open) and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
No FWD position signal input is detected when the vehicle speed changes from 6 mph (10 km/h) --> 25 mph (40 km/h) --> 6 mph (10 km/h) in D or S.

Driving Pattern






1. Start the engine.
2. Accelerate the vehicle in D to 25 mph (40 km/h) or more.
3. Slow down to 6 mph (10 km/h) for several seconds.
4. Stop the vehicle, and turn the ignition switch to LOCK (0) or press the engine start/stop button to select the OFF mode.
5. Repeat Driving Pattern steps 1 through 4.

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.