DTC P1235: High Pressure Fuel Pump Circuit [09/2014 - 11/2017]: Procedure

1. Inspect the fuel pump (for high pressure side).

   Refer to INSPECTION [09/2014 - 11/2017]

   HINT: 

   Perform "Inspection After Repair" after replacing the fuel pump (for high pressure side).

   Refer to INITIALIZATION [09/2014 - 11/2017]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE FUEL PUMP (FOR HIGH PRESSURE SIDE). Refer to  REMOVAL [09/2014 - 11/2017] 

Result: 

OK 

See step  2

1. Disconnect the injector driver (EDU) connector.
2. Disconnect the fuel pump (for high pressure side) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F36-3 (FP+) - F51-1 (FP+)	Always	Below 1 Ω
   F36-4 (FP-) - F51-2 (FP-)	Always	Below 1 Ω
   F36-3 (FP+) or F51-1 (FP+) - Body ground	Always	10 kΩ or higher
   F36-4 (FP-) or F51-2 (FP-) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Disconnect the ECM connector.
2. Disconnect the injector driver (EDU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F3-10 (FPF1) - F34-7 (FPF1)	Always	Below 1 Ω
   F3-11 (FPD) - F34-8 (FPD)	Always	Below 1 Ω
   F3-10 (FPF1) or F34-7 (FPF1) - Body ground	Always	10 kΩ or higher
   F3-11 (FPD) or F34-8 (FPD) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Turn the engine switch off.
2. Inspect the ECM using an oscilloscope.
   1. While cranking the engine, check the waveform the terminals of the ECM connector.

      ECM Terminal Name	F3-11 (FPD) - F4-1 (E1)
      Tester Range	2 V/DIV., 5 ms./DIV.
      Condition	Cranking

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      *a

      Component with harness connected (ECM)

      *b

      FPD Terminal Waveform Normal Waveform

      Standard

      Signal waveform appears as shown in the illustration.

      HINT: 

      The FPD terminal waveform is output only right after the engine starts. If this DTC is stored when the engine is started from engine switch off, the system enters fail-safe mode and the waveform is not output.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  6

Result: 

OK 

See step  5

1. Turn the engine switch off.
2. Inspect the ECM using an oscilloscope.
   1. While cranking the engine, check the waveform the terminals of the ECM connector.

      ECM Terminal Name	CH1: F3-11 (FPD) - F4-1 (E1) CH2: F3-10 (FPF1) - F4-1 (E1)
      Tester Range	2 V/DIV., 5 ms./DIV.
      Condition	Cranking

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      *a	Component with harness connected (ECM)	*b	FPD Terminal and FPF1 Terminal Waveform Normal Waveform
      *c	FPF1 Terminal Waveform NG Waveform 1	*d	FPF1 Terminal Waveform NG Waveform 2

      HINT: 

      FPD terminal waveform is output only right after the engine starts.

   Result

   FPD Terminal Waveform	FPF1 Terminal Waveform		Proceed to
   OK	OK		A
   OK	NG waveform 1*	Does not change from NG waveform 1 (FPF1 terminal waveform remains at GND even after disconnecting the injector driver (EDU) connector and cranking the engine)
   		Changes to NG waveform 2 (FPF1 terminal waveform rises from GND after disconnecting the injector driver (EDU) connector and cranking the engine)	B
   OK	NG waveform 2

   HINT: 

   *: If the FPF1 terminal waveform is similar to the FRF1 terminal waveform NG waveform 1, stop the engine and disconnect F34 injector driver (EDU) connector. Then, while cranking the engine, check to see if there is a difference between the FPF1 terminal waveform and the previous one.

Result: 

A 

REPLACE ECM. Refer to  REMOVAL [09/2014 - 11/2017] 

Result: 

B 

REPLACE INJECTOR DRIVER (EDU). Refer to  REMOVAL [09/2014 - 11/2017] 

1. Turn the engine switch off.
2. Disconnect the F34 injector driver (EDU) connector.
3. Inspect the ECM using an oscilloscope.
   1. While cranking the engine, check the waveform the terminals of the ECM connector.

      ECM Terminal Name	F3-11 (FPD) - F4-1 (E1)
      Tester Range	2 V/DIV., 5 ms./DIV.
      Condition	Cranking

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      *a

      Component with harness connected (ECM)

      *b

      FPD Terminal Waveform Normal Waveform

      Standard

      Signal waveform appears as shown in the illustration.

      HINT: 

      FPD terminal waveform8 is output only right after the engine starts.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE INJECTOR DRIVER (EDU). Refer to  REMOVAL [09/2014 - 11/2017] 

Result: 

NG 

REPLACE ECM. Refer to  REMOVAL [09/2014 - 11/2017]