DTC P1235 High Pressure Fuel Pump Circuit: Wiring Diagram

Fig 1: Wiring Diagram - High Pressure Fuel Pump Circuit

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (See FREEZE FRAME DATA  ).

1. INSPECT FUEL PUMP FOR HIGH PRESSURE 
   1. Disconnect the E41 fuel pump for high pressure connector.
   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      1 - 2	20°C (68°F)	1.19 to 1.39 Ω

      Fig 2: Identifying Fuel Pump For High Pressure Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Reconnect the fuel pump for high pressure connector.

   NG : REPLACE FUEL PUMP FOR HIGH PRESSURE 

   OK : GO TO NEXT STEP 

2. CHECK HARNESS AND CONNECTOR (INJECTOR DRIVER - FUEL PUMP FOR HIGH PRESSURE) 
   1. Disconnect the E27 injector driver (EDU) connector.
   2. Disconnect the E41 fuel pump for high pressure connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Specified Condition
      FP+ (E27-3) - E41-1	Below 1 Ω
      FP- (E27-4) - E41-2	Below 1 Ω

      Standard resistance (Check for short) 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Specified Condition
      FP+ (E27-3) or E41-1 - Body ground	10 kΩ or higher
      FP- (E27-4) or E41-2 - Body ground	10 kΩ or higher

      Fig 3: Identifying Injector Driver (EDU) Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. Reconnect the injector driver (EDU) connector.
   5. Reconnect the fuel pump for high pressure connector.

   NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK : GO TO NEXT STEP 

3. INSPECT ECM (FPD AND FPF1 VOLTAGE) 
   1. Start the engine, and check the waveforms between terminals FPF1 and E1, and FPD and E1 of the E6 and E4 ECM connectors.

      HINT:

      The correct waveform is as shown in the illustration.

      ECM TERMINAL NAME AND TESTER RANGE SPECIFICATION
      
      

      ECM Terminal Name	CH1: FPD (E6-33) - E1 (E4-7) CH2: FPF1 (E6-32) - E1 (E4-7)
      Tester Range	2 V/DIV. 5 ms./DIV.
      Conditions	Idling with warm engine

      Fig 4: Signal Waveform Graph

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK : REPLACE ECM 

   NG : GO TO NEXT STEP 

4. CHECK HARNESS AND CONNECTOR (INJECTOR DRIVER - ECM) 
   1. Disconnect the E6 ECM connector.
   2. Disconnect the E26 injector driver (EDU) connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Specified Condition
      FPF1 (E6-32) - FPF1 (E26-7)	Below 1 Ω
      FPD (E6-33) - FPD (E26-8 )	Below 1 Ω

      Standard resistance (Check for short) 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Specified Condition
      FPF1 (E6-32) or FPF1 (E26-7) - Body ground	10 kΩ or higher
      FPD (E6-33) or FPD (E26-8 ) - Body ground	10 kΩ or higher

      Fig 5: Identifying E6 ECM Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. Reconnect the ECM connector.
   5. Reconnect the injector driver (EDU) connector.

   NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK : REPLACE INJECTOR DRIVER