Power Source Mode does not Change: Description

If the certification ECU detects the key inside the vehicle when the shift lever position is P (A/T) and the brake pedal (A/T) or the clutch pedal (M/T) is not depressed, each press of the engine switch changes the power source mode in the following order: off, on (ACC), on (IG), off. If one of the DTCs shown in the following illustration is detected, correct the DTCs according to the DTC chart. If the power source mode is still malfunctioning, one of the following may have occurred: 1) the MPX circuit has a malfunction, 2) the certification ECU has determined that the electrical key is not inside the vehicle, 3) the engine switch has a malfunction, or 4) the power source control ECU has a malfunction.

Fig 1: Power Source Mode Not Change Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. CHECK FOR DTCS 
   1. Delete the DTCs (See DIAGNOSIS SYSTEM  ).

      HINT:

      After all DTCs are cleared, check if the trouble occurs again 5 seconds after the engine switch is turned on (IG).

   2. Check for DTCs again.

      OK: No DTC is output. 

   NG : GO TO  DTC CHART  

   OK : GO TO NEXT STEP 

2. CHECK BASIC FUNCTION 
   1. Check the basic function.
      1. A/T Models: When the key is inside the vehicle and the shift lever position is in P, check that depressing the brake pedal causes the engine switch indicator to turn green.
      2. M/T Models: When the key is inside the vehicle, check that depressing the clutch pedal and brake pedal causes the engine switch indicator to turn green.

         Result 

         RESULT CHART
         
         

         Result	Proceed to
         Indicator turns green	A
         Engine switch indicator circuit is normal but the indicator does not turn green	B
         Room oscillator recognizes key but the indicator does not turn green	C

      B : GO TO ROOM OSCILLATOR CIRCUIT 

      C : GO TO  ENGINE SWITCH INDICATOR CIRCUIT  

      A : SYSTEM IS OK