DTC P2798-858: Auxiliary Transmission Fluid Pump Control Circuit Low: Procedure

1. Disconnect connector A55 from the oil pump motor controller.
   Fig 1: Identifying A55 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Specified Condition
   OPST (A55-7) - Body ground	7 to 12 V

   NOTE:

   Turning the power switch on (IG) with the oil pump motor controller connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

OK → See step   3 

NG: Go to next step 

1. Turn the power switch off.
   Fig 2: Identifying A54 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect connector A54 from the hybrid vehicle control ECU.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   OPST (A54-2) - Body ground	10 kΩ or more

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   7 

1. Turn the power switch off.
   Fig 3: Identifying A55 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   OPST (A55-7) - Body ground	10 kΩ or more

NG → See step   8 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Read and record the DTCs and freeze frame data.
4. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
5. Clear the DTCs.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
4. Read output DTCs.

   Result

   DTC P2798-858 is output.

YES → See step   7 

NO: Go to next step 

1. Check for intermittent problems. Refer to CHECK FOR INTERMITTENT PROBLEMS .

NG → REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA 

OK → See step   9