Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Intermediate Shaft Speed Sensor "A" Circuit Short to Battery (P079112,P079114,P079131)

Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual / Drivetrain / U881e (automatic Transmission / Transaxle) / Automatic Transaxle System / Intermediate Shaft Speed Sensor "A" Circuit Short to Battery (P079112,P079114,P079131)

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 and NC3) signals, the ECM controls engine torque and shift timing.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P079112	Intermediate Shaft Speed Sensor "A" Circuit Short to Battery	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off. Transmission revolution sensor (NC) input signal voltage is more than 1.9 V 2 seconds 1-trip detection logic	Transmission revolution sensor (NC) Transmission wire Harness and connector ECM	Comes on	DTC stored	SAE Code P07C6
P079114	Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off. Transmission revolution sensor (NC) input signal voltage is less than 0.1 V 2 seconds 1-trip detection logic	Transmission revolution sensor (NC) Transmission wire Harness and connector ECM	Comes on	DTC stored	SAE Code P07C5
P079131	Intermediate Shaft Speed Sensor "A" No Signal	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other All of the following conditions are met: The battery voltage is 8 V or more. Park/neutral position switch D input signal is ON The vehicle speed is 16 km/h (10 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 5 seconds 1-trip detection logic	Transmission revolution sensor (NC) Transmission wire Harness and connector ECM	Comes on	DTC stored	SAE Code P0793

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P079112

Intermediate Shaft Speed Sensor "A" Circuit Short to Battery

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off.
Transmission revolution sensor (NC) input signal voltage is more than 1.9 V
2 seconds
1-trip detection logic

Transmission revolution sensor (NC)
Transmission wire
Harness and connector
ECM

Comes on

DTC stored

SAE Code

P07C6

P079114

Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off.
Transmission revolution sensor (NC) input signal voltage is less than 0.1 V
2 seconds
1-trip detection logic

Transmission revolution sensor (NC)
Transmission wire
Harness and connector
ECM

Comes on

DTC stored

SAE Code

P07C5

P079131

Intermediate Shaft Speed Sensor "A" No Signal

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

All of the following conditions are met:
1. The battery voltage is 8 V or more.
2. Park/neutral position switch D input signal is ON
3. The vehicle speed is 16 km/h (10 mph) or more.
4. Speed indicated by transmission revolution sensor (NT) is higher than specified value
Speed indicated by transmission revolution sensor (NC) is less than 300 rpm
5 seconds
1-trip detection logic

Transmission revolution sensor (NC)
Transmission wire
Harness and connector
ECM

Comes on

DTC stored

SAE Code

P0793

MONITOR DESCRIPTION

The transmission revolution sensor (NC) monitors the output shaft speed.

The ECM commands gear changes and controls the lock up timing based on the signals from the transmission revolution sensor (NC) and throttle position sensor.

If the vehicle is being driven at 16 km/h (10 mph) or more and the speed sensor (NC) signal sent to the ECM is less than 300 rpm, or if the transmission revolution sensor (NC) input signal voltage is less than 0.1 V or more than 1.9 V, the ECM will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs	P0793: Speed sensor (NC)/Verify pulse input P07C5: Speed sensor (NC)/Range check (Low voltage) P07C6: Speed sensor (NC)/Range check (High voltage)
Required sensors/Components	Speed sensor (NT), Speed sensor (NC3), Speed sensor (NC)
Frequency of operation	Continuous
Duration	P0793: 5 sec. P07C5 and P07C6: 2 sec.
MIL operation	Immediate
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

All

Battery voltage	8 V or more
Engine switch	On (IG)
Starter	OFF

P0793

The monitor will run whenever the following DTCs are not present	P07C5, P07C6 (Intermediate shaft speed sensor circuit) U0100 (CAN communication system) P2716 (Pressure control solenoid circuit)
Intermediate shaft speed sensor range check fail (P07C5, P07C6) (Pending / MIL)	Not detected
Vehicle speed	16 km/h (9.9 mph) or more
Shift change is completed and before starting next shift change operation	-
Park/neutral position switch	OFF
R range position switch	OFF
D range position switch	ON
Engine	Running
Lost communication with ECM/PCM (U0100) (Pending + MIL)	Not detected
Pressure control solenoid circuit fail (P2716) (Pending + MIL)	Not detected

One of the following condition is met: Condition (a), (b), (c), (d), (e), (f), (g) or (h) Condition (a)

ECM selected gear

1st

Turbine Speed Sensor revolution

1830 rpm or more

Condition (b)

ECM selected gear

2nd

Turbine Speed Sensor revolution

1060 rpm or more

Condition (c)

ECM selected gear

3rd

Turbine Speed Sensor revolution

680 rpm or more

Condition (d)

ECM selected gear

4th

Turbine Speed Sensor revolution

510 rpm or more

Condition (e)

ECM selected gear

5th

Turbine Speed Sensor revolution

430 rpm or more

Condition (f)

ECM selected gear

6th

Turbine Speed Sensor revolution

350 rpm or more

Condition (g)

ECM selected gear

7th

Turbine Speed Sensor revolution

300 rpm or more

Condition (h)

ECM selected gear

8th

Turbine Speed Sensor revolution

300 rpm or more

P07C5, P07C6

The monitor will run whenever the following DTCs are not stored

P0793 (Intermediate shaft speed sensor verify pulse input)

Intermediate shaft speed sensor pulse input fail (P0793)

(Pending / MIL)

Not detected

TYPICAL MALFUNCTION THRESHOLDS

P0793

Intermediate shaft speed sensor revolution

Less than 300 rpm

P07C5

Intermediate shaft speed sensor voltage

Less than 0.1 V

P07C6

Intermediate shaft speed sensor voltage

More than 1.9 V

COMPONENT OPERATING RANGE

Intermediate shaft speed sensor revolution	300 rpm or more
Intermediate shaft speed sensor voltage	0.1 V or more and 1.9 V or less

CONFIRMATION DRIVING PATTERN

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.
Click here

Connect the Techstream to the DLC3.
Turn the engine switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for 2 minutes or more.
Turn the engine switch on (IG) and turn the Techstream on.
Start the engine.
Perform the D Position Shift Test inspection in Road Test. [*1]
Click here

HINT:

[*1] : Normal judgment procedure.

The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
Input the DTC: P079112, P079114 or P079131.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Perform the universal trip to clear permanent DTCs.
Click here
Perform registration and/or initialization when parts related to the automatic transaxle are replaced.
Click here

DATA LIST

NOTICE:

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

HINT:

Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

(a) Warm up the engine.

(b) Turn the engine switch off.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Transmission / Data List / NC Sensor Speed.

(g) Read the Data List according to the display on the Techstream.

Powertrain > Transmission > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
NC Sensor Speed	Counter gear speed	Min.: 0 rpm Max.: 12750 rpm	-	-

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

NC Sensor Speed

Counter gear speed

Min.: 0 rpm

Max.: 12750 rpm

Powertrain > Transmission > Data List

Tester Display
NC Sensor Speed

HINT:

NC Sensor Speed is always 0 while driving: Open or short in the sensor or circuit.
NC Sensor Speed is always more than 0 and less than 300 rpm while driving the vehicle at 16 km/h (10 mph) or more: Sensor malfunction, improper installation, or intermittent connection malfunction in the circuit.

PROCEDURE

1.	READ VALUE USING TECHSTREAM (NC SENSOR SPEED AND NC SENSOR VOLTAGE)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Enter the following menus: Powertrain / Transmission / Data List / NC Sensor Speed and NC Sensor Voltage.

(e) Read the Data List according to the display on the Techstream.

Powertrain > Transmission > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
NC Sensor Speed	Counter gear speed	Min.: 0 rpm Max.: 12750 rpm	-	-
NC Sensor Voltage	NC sensor voltage	Min.: 0.000 V Max.: 4.999 V	0.1 to 1.9 V: Engine idling	-

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

NC Sensor Speed

Counter gear speed

Min.: 0 rpm

Max.: 12750 rpm

NC Sensor Voltage

NC sensor voltage

Min.: 0.000 V

Max.: 4.999 V

0.1 to 1.9 V: Engine idling

Powertrain > Transmission > Data List

Tester Display
NC Sensor Speed
NC Sensor Voltage

Result	Proceed to
Data List value is normal	A
Data List value is not normal	B

GO TO STEP 5

2.	INSPECT TRANSMISSION REVOLUTION SENSOR (NC) (NC TERMINAL)

(a) Disconnect the D56 transmission wire connector.

*a	Front view of wire harness connector (to Transmission Wire)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D56-22 (NCO) - Body ground	Always	99 to 101 Ω

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
D56-21 (NCB) - Body ground	Engine switch on (IG)	11 to 14 V

GO TO STEP 4

3.	INSPECT TRANSMISSION WIRE (TRANSMISSION REVOLUTION SENSOR (NC))

(a) Disconnect the transmission revolution sensor (NC) connector.

Click here

Front view of wire harness connector

(to Transmission Revolution Sensor (NC))

Component without harness connected

(Transmission Wire)

(b) Disconnect the D56 transmission wire connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
Transmission revolution sensor (NC) connector terminal 1 - D56-21 (NCB)	Always	Below 1 Ω
Transmission revolution sensor (NC) connector terminal 2 - D56-22 (NCO)	Always	Below 1 Ω
Transmission revolution sensor (NC) connector terminal 1 or D56-21 (NCB) - Body ground	Always	10 kΩ or higher
Transmission revolution sensor (NC) connector terminal 2 or D56-22 (NCO) - Body ground	Always	10 kΩ or higher

REPLACE TRANSMISSION REVOLUTION SENSOR (NC)

REPAIR OR REPLACE TRANSMISSION WIRE

4.	CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)

(a) Disconnect the D56 transmission wire connector.

(b) Disconnect the D2 ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D56-21 (NCB) - D2-73 (NCB)	Always	Below 1 Ω
D56-22 (NCO) - D2-72 (NCO)	Always	Below 1 Ω
D56-21 (NCB) or D2-73 (NCB) - Body ground	Always	10 kΩ or higher
D56-22 (NCO) or D2-72 (NCO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR (TRANSMISSION WIRE - ECM)

5.	REPLACE ECM

(a) Replace the ECM.

Click here

PERFORM A/T CODE REGISTRATION

Pressure Control Solenoid "B" Actuator Stuck Off (P07757F)

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Pressure Control Solenoid "C" Circuit Open (P079513)

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Other materials:

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Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Intermediate Shaft Speed Sensor "A" Circuit Short to Battery (P079112,P079114,P079131)

Pressure Control Solenoid "B" Actuator Stuck Off (P07757F)

Pressure Control Solenoid "C" Circuit Open (P079513)

Other materials:

Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual

ECM selected gear	1st
Turbine Speed Sensor revolution	1830 rpm or more

ECM selected gear	2nd
Turbine Speed Sensor revolution	1060 rpm or more

ECM selected gear	3rd
Turbine Speed Sensor revolution	680 rpm or more

ECM selected gear	4th
Turbine Speed Sensor revolution	510 rpm or more

ECM selected gear	5th
Turbine Speed Sensor revolution	430 rpm or more

ECM selected gear	6th
Turbine Speed Sensor revolution	350 rpm or more