DTC B2281: "P" Signal Malfunction: Procedure

1. Connect Techstream to the DLC3.
2. Turn the engine switch on (IG) and press Techstream main switch on.
3. Read the DATA LIST according to the displays on the tester.
   POWER SOURCE CONTROL:
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Shift P Signal	Shift P Signal / ON or OFF	ON: Shift P signal ON (Shift position is P) OFF: Shift P signal OFF (Shift position is not P)	-

   OK

   "ON" (P signal is ON) appears on the screen.

   Result

   Condition	Proceed to
   NG	C
   OK (When troubleshooting according to the PROBLEM SYMPTOM TABLE)	B
   OK (When troubleshooting according to the DTC chart)	A

B → PROCEED TO  PROBLEM SYMPTOMS TABLE  NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

C → See step   2 

A → REPLACE POWER SOURCE CONTROL ECU 

1. Disconnect the D44 ECU connector.
   Fig 1: Identifying D44 ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D25 ECU connector.
   Fig 2: Identifying D25 ECU Connector Terminals

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

   Resistance

   Terminal No. (Symbol)	Specified Condition
   D44-5 (P) - D25-11 (P2)	Below 1 Ω
   D44-5 (P) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. After replacing the power source control ECU with a normally functioning ECU, check that the push button start function can start normally.

   OK

   Push button start function can start normally.

NG → GO TO  AUTOMATIC TRANSAXLE SYSTEM  SHIFT CONTROL SYSTEM 

OK → END (POWER SOURCE CONTROL ECU DEFECTIVE)