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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission System (UA80F) - Diagnostic Codes (2 Of 2) & Symptom Tests >> Automatic Transaxle System >> DTC P0791-12: Intermediate Shaft Speed Sensor "A" Circuit Short to Battery; DTC P0791-14: Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open; DTC P0791-31: Intermediate Shaft Speed Sensor "A" No Signal [12/2019 - 10/2022] >> Description

DTC P0791-12: Intermediate Shaft Speed Sensor "A" Circuit Short to Battery; DTC P0791-14: Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open; DTC P0791-31: Intermediate Shaft Speed Sensor "A" No Signal [12/2019 - 10/2022]: Description

The transmission revolution sensor (NC) detects the rotation speed of the counter gear which shows the output shaft speed of automatic transaxle assembly.

Based on the transmission revolution sensor (NC) signal and the transmission revolution sensor (NT) signal, the ECM controls engine torque and shift timing.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory Note
P0791-12 Intermediate Shaft Speed Sensor "A" Circuit Short to Battery All of the following conditions are met (1-trip detection logic):
  • The battery voltage is 8 V or more.
  • The ignition switch is ON.
  • The starter is off.
  • Transmission revolution sensor (NC) input voltage is more than 1.9 V for 2 seconds.
  • Transmission revolution sensor (NC)
  • Transmission wire
  • Harness and connector
  • ECM
Comes on DTC stored SAE Code:
P07C6
P0791-14 Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open All of the following conditions are met (1-trip detection logic):
  • The battery voltage is 8 V or more.
  • The ignition switch is ON.
  • The starter is off.
  • Transmission revolution sensor (NC) input voltage is less than 0.1 V for 2 seconds.
  • Transmission revolution sensor (NC)
  • Transmission wire
  • Harness and connector
  • ECM
Comes on DTC stored SAE Code:
P07C5
P0791-31 Intermediate Shaft Speed Sensor "A" No Signal All of the following conditions are met (1-trip detection logic):
  • The battery voltage is 8 V or more.
  • Park/neutral position switch D input signal is ON.
  • The vehicle speed is 25 km/h (16 mph) or more.
  • Speed indicated by transmission revolution sensor (NT) is higher than specified value.
  • Speed indicated by transmission revolution sensor (NC) is less than 300 rpm for 2 seconds.
  • Transmission revolution sensor (NC)
  • Transmission wire
  • Harness and connector
  • ECM
Comes on DTC stored SAE Code:
P0793
DTC DETECTION CONDITION PATTERNS (P0791-31):

  Vehicle Condition
Pattern 1 Pattern 2 Pattern 3 Pattern 4
Diagnostic Condition The battery voltage is 8 V or more.
Park/neutral position switch D input signal is ON.
The vehicle speed is 25 km/h (16 mph) or more.
When the vehicle is being driven in 1st gear, the transmission revolution sensor (NT) value is 2390 rpm or more. - - -
When the vehicle is being driven in 2nd gear, the transmission revolution sensor (NT) value is 1380 rpm or more. - - -
When the vehicle is being driven in 3rd gear, the transmission revolution sensor (NT) value is 890 rpm or more. - - -
When the vehicle is being driven in 4th gear, the transmission revolution sensor (NT) value is 620 rpm or more. - - -
Malfunction Condition Speed indicated by transmission revolution sensor (NC) is less than 300 rpm.
Duration 2 seconds or more 2 seconds or more 2 seconds or more 2 seconds or more
Detection Logic 1-trip detection logic 1-trip detection logic 1-trip detection logic 1-trip detection logic
DTC DETECTION CONDITION PATTERNS (P0791-31):

  Vehicle Condition
Pattern 5 Pattern 6 Pattern 7 Pattern 8
Diagnostic Condition The battery voltage is 8 V or more.
Park/neutral position switch D input signal is ON.
The vehicle speed is 25 km/h (16 mph) or more.
When the vehicle is being driven in 5th gear, the transmission revolution sensor (NT) value is 540 rpm or more. - - -
When the vehicle is being driven in 6th gear, the transmission revolution sensor (NT) value is 440 rpm or more. - - -
When the vehicle is being driven in 7th gear, the transmission revolution sensor (NT) value is 350 rpm or more. - - -
When the vehicle is being driven in 8th gear, the transmission revolution sensor (NT) value is 300 rpm or more. - - -
Malfunction Condition Speed indicated by transmission revolution sensor (NC) is less than 300 rpm.
Duration 2 seconds or more 2 seconds or more 2 seconds or more 2 seconds or more
Detection Logic 1-trip detection logic 1-trip detection logic 1-trip detection logic 1-trip detection logic

HINT: 

DTC P0791-31 is stored when any of the above detection patterns is met.