DTC P0873: Transmission Fluid Pressure Sensor / Switch "C" Circuit High [11/2021 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / ECT / Active Test / Control the Shift Position / Data List / TPS 1 Switch.

   Powertrain > ECT > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Control the Shift Position	Operates the shift solenoid valves to allow gears to be selected manually.	Press "→" button: Upshift occurs Press "←" button: Downshift occurs	Possible to check operation of the shift solenoid valves. [Vehicle Condition] Vehicle speed: 50 km/h (31 mph) or less

   Powertrain > ECT > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   TPS 1 Switch	Oil pressure switch status	ON or OFF	ON: Gear is 1st to 5th OFF: Gear is 6th to 8th; or shift lever is in P, N or R	-

   Powertrain > ECT > Active Test 

   Active Test Display
   Control the Shift Position

   Data List Display
   TPS 1 Switch

   Result

   Result	Proceed to
   When the engine is idling with the shift lever in P, N or R, ON is displayed for TPS 1 Switch on the Data List.	A
   When the vehicle is being driven in a gear position between 6th and 8th or when the engine is idling with the shift lever in P, N or R, OFF is displayed for TPS 1 Switch on the Data List.	B
   When the vehicle is being driven in a gear position between 6th and 8th, ON is displayed for TPS 1 Switch on the Data List.	C

Result: 

B 

See step  6

Result: 

C 

See step  7

Result: 

A 

See step  2

1. Turn the engine switch off.

   HINT: 

   Before checking, perform visual and contact pressure checks on the TCM connectors.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (TCM)

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F156-9 (TPS1) - Body ground	Engine switch off	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  5

Result: 

OK 

See step  3

1. Remove the shift solenoid valve SL1.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component without harness connected (Shift Solenoid Valve SL1)

   Refer to DISASSEMBLY [11/2021 - ]

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Terminal 1 of the shift solenoid valve SL1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω

3. Connect a positive (+) lead from the battery with a 21 W bulb to terminal 2 and a negative (-) lead to terminal 1 of the solenoid valve connector. Check that the valve moves and makes an operating sound.

   OK

   Valve moves and makes an operating sound.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE SHIFT SOLENOID VALVE SL1. Refer to  COMPONENTS [11/2021 - ] 

Result: 

OK 

See step  4

1. Check the transmission valve body assembly.

   Refer to REMOVAL [11/2021 - ]

   OK

   There is no foreign matter on each valve and they operate smoothly.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY. Refer to  COMPONENTS [11/2021 - ] 

Result: 

NG 

REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY. Refer to  COMPONENTS [11/2021 - ] 

1. Disconnect the F156 TCM connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Rear view of wire harness connector (to TCM)

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F156-9 (TPS1) - Body ground	Engine switch off	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  6

Result: 

NG 

See step  7

1. Replace the TCM.

   Refer to COMPONENTS [11/2021 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

PERFORM A/T CODE REGISTRATION. Refer to  REGISTRATION [11/2021 - ] 

1. Disconnect the F175 transmission wire connector.
2. Disconnect the F156 TCM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F175-17 (TPS1) - F156-9 (TPS1)	Always	Below 1 Ω
   F175-17 (TPS1) or F156-9 (TPS1) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

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

Result: 

OK 

See step  8

1. Disconnect the oil pressure switch connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Oil Pressure Switch Connector)
   *b	Component without harness connected (Transmission Wire)
   *c	Connector

   Refer to DISASSEMBLY [11/2021 - ]

2. Disconnect the F175 transmission wire connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Oil pressure switch connector - 17 (TPS1)	Always	Below 1 Ω
   Oil pressure switch connector or 17 (TPS1) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE OIL PRESSURE SWITCH. Refer to  COMPONENTS [11/2021 - ] 

Result: 

NG 

REPAIR OR REPLACE TRANSMISSION WIRE. Refer to  COMPONENTS [11/2021 - ]