DTC B22A1: Battery Current Sensor: Procedure

Fig 1: Measuring Battery Current

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Put the vehicle in a no load test condition. Then set the headlights to high beam, set the heater blower switch to Hi, and run the engine at 2000 rpm. Using an electrical tester and probes, measure the current.
2. Using the Techstream, read the Data List.
   ELECTRIC POWER CONTROL
   
   

   Item	Measurement Item/Display (Range)	Normal Condition	Diagnostic Note
   Electrical Charge Current	Current battery current value display/ Min.: -300, Max.: 100 [A]	Amperage value is displayed	-

   OK

   Values of electrical tester and the Techstream are almost the same.

NG → See step   4 

OK: Go to next step 

Fig 2: Identifying A49 Sensor Connector Terminals With Resistance Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the A49 sensor connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A49-1 (THB) - A49-4 (E2)	20 to 30°C (68 to 86°F)	1.5 to 2.1 kΩ
   	(0 to 70°C (32 to 158°F))	(0.3 to 6.0 kΩ)

   NOTE: The temperature shown in the inspection condition is for the area surrounding the sensor, not the sensor itself.

NG → See step   8 

OK: Go to next step 

Fig 3: Identifying A69 ECU And A49 Sensor Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the A69 ECU connector.
2. Disconnect the A49 sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A69-20 (THB) - A49-1 (THB)	Always	Below 1 Ω
   A69-20 (THB) or A49-1 (THB) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE PASSENGER SIDE JUNCTION BLOCK (ELECTRIC POWER CONTROL ECU) 

Fig 4: Identifying A49 Sensor Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the A49 sensor connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Switch Condition	Specified Condition
   A49-2 (VC5) - A49-4 (E2)	Engine switch on (IG)	4.5 to 5.5 V

OK → See step   6 

NG: Go to next step 

Fig 5: Identifying A49 Sensor Connector And A69 ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the A69 ECU connector.
2. Disconnect the A49 sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A69-6 (VC) - A49-2 (VC5)	Always	Below 1 Ω
   A69-10 (E2) - A49-4 (E2)	Always	Below 1 Ω
   A69-6 (VC) or A49-2 (VC5) - Body ground	Always	10 kΩ or higher
   A69-10 (E2) or A49-4 (E2) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE PASSENGER SIDE JUNCTION BLOCK (ELECTRIC POWER CONTROL ECU) 

Fig 6: Identifying A49 Sensor Connector And A69 ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the A69 ECU connector.
2. Disconnect the A49 sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A69-9 (IB) - A49-3 (IB)	Always	Below 1 Ω
   A69-9 (IB) or A49-3 (IB) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Temporarily replace the battery current sensor with a new or normally functioning one. Refer to REMOVAL .
2. Delete the DTC. Refer to DTC CHECK/CLEAR .
3. Check for DTC again. Refer to DTC CHECK/CLEAR .

   OK

   No DTC is output.

NG → REPLACE PASSENGER SIDE JUNCTION BLOCK (ELECTRIC POWER CONTROL ECU) 

OK → END (BATTERY CURRENT SENSOR IS DEFECTIVE)