DTC P0AA1-231: Hybrid Battery Positive Contactor Circuit Stuck Closed: Procedure

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. Check if DTCs are output.

   Result

   Result	Proceed to
   P0AA1-231 only is output.	A
   Any of the following DTCs are also output.	B

   DTC No.	Relevant Diagnosis
   P0A1A-151, 155, 156, 200, 201, 658, 659, 791, 792, 793	Generator Control Module
   P0A1B-163, 164, 168, 192, 193, 511, 512, 661, 794, 795, 796, 786, 788	Drive Motor "A" Control Module
   P0A3F-243	Drive Motor "A" Position Sensor Circuit
   P0A41-245	Drive Motor "A" Position Sensor Circuit Low
   P0A40-500	Drive Motor "A" Position Sensor Circuit Range / Performance
   P0A4B-253	Generator Position Sensor Circuit
   P0A4C-513	Generator Position Sensor Circuit Range / Performance
   P0A4D-255	Generator Position Sensor Circuit Low
   P0A78-266, 267, 586	Drive Motor "A" Inverter Performance
   P0A94-442	DC / DC Converter Performance
   P0ADC-226	Hybrid Battery Positive Contactor Control Circuit High
   P0AE2-161, 773	Hybrid Battery Precharge Contactor Circuit Stuck Closed
   P0C76-523	Hybrid Battery System Discharge Time Too Long
   P3004-132	Power Cable Malfunction
   P3240-443	DC / DC Converter Control Circuit

B → See step   6 

A: Go to next step 

1. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
2. Read the freeze frame data of DTC P0AA1-231.

   Result

   Result	Proceed to
   Pre-boost voltage (VL) is less than 60 V.	A
   Post-boost voltage (VL) is 60 V or more.	B

A → See step   5 

B: Go to next step 

1. Turn the power switch off.
2. Remove the service plug grip. Refer to PRECAUTION .
   Fig 1: Identifying HV Battery Junction Block

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE:

   After removing the service plug grip, do not turn the power switch on (READY) unless instructed by the repair information because this may cause a malfunction.

   HINT: 

   For the removal and installation procedures related to inspection of the HV battery junction block. Refer to COMPONENTS .

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

   Standard resistance

   Tester Connection	Switch Condition	Specified Condition
   g2-1 - z30-1	Power switch off	10 kΩ or higher

   HINT: 

   • If a system main relay is stuck closed, impacts or vibrations during the inspection may cause it to open.
   • If the result of reading the freeze frame data in the previous step was B, the HV battery junction block must be replaced. Measuring resistance can determine whether this is either a present or past malfunction.

NG → See step   4 

OK → See step   4