DTC P1235: High Pressure Fuel Pump Circuit [06/2016 - ]: Procedure

1. Inspect the fuel pump assembly (for high pressure) (Refer to INSPECTION [06/2016 - ] ).

Result: 

NG 

REPLACE FUEL PUMP ASSEMBLY (FOR HIGH PRESSURE) 

(Refer to REMOVAL [06/2016 - ] )

Result: 

OK 

See step  2

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

   Standard Resistance (Check for open)

   Tester Connection	Condition	Specified Condition
   C2-3 (FP-) - C29-2	Always	Below 1 Ω
   C2-4 (FP+) - C29-1	Always	Below 1 Ω

   Standard Resistance (Check for short)

   Tester Connection	Condition	Specified Condition
   C2-3 (FP-) or C29-2 - Body ground	Always	10 kΩ or higher
   C2-4 (FP+) or C29-1 - Body ground	Always	10 kΩ or higher

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 (Check for open)

   Tester Connection	Condition	Specified Condition
   A34-32 (FPD) - C1-8 (FPD)	Always	Below 1 Ω
   A34-13 (FPF) - C1-7 (FPF)	Always	Below 1 Ω

   Standard Resistance (Check for short)

   Tester Connection	Condition	Specified Condition
   A34-32 (FPD) or C1-8 (FPD) - Body ground	Always	10 kΩ or higher
   A34-13 (FPF) or C1-7 (FPF) - Body ground	Always	10 kΩ or higher

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Turn the ignition switch to ON.
2. Inspect the ECM using an oscilloscope.
   1. While idling the engine, check the waveform the terminals of the ECM connector.

      ECM Terminal Name	A34-32 (FPD) - Body ground
      Tester Range	2 V/DIV., 20 ms./DIV.
      Condition	Idling

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      TEXT IN ILLUSTRATION
      
      

      *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 ignition switch off, the system enters fail-safe mode and the waveform is not output.

Result: 

NG 

See step  6

Result: 

OK 

See step  5

1. Turn the ignition switch to ON.
2. Inspect the ECM using an oscilloscope.
   1. While idling the engine, check the waveform the terminals of the ECM connector.

      ECM Terminal Name	CH1: A34-32 (FPD) - Body ground CH2: A34-13 (FPF) - Body ground
      Tester Range	2 V/DIV., 20 ms./DIV.
      Condition	Idling

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      TEXT IN ILLUSTRATION
      
      

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

      HINT: 

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

   Result

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

Result: 

A 

REPLACE ECM 

(Refer to REMOVAL [06/2016 - ] )

Result: 

B 

REPLACE INJECTOR DRIVER (EDU) 

(Refer to REMOVAL [06/2016 - ] )

1. Turn the ignition switch to ON.
2. Disconnect the 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	A34-32 (FPD) - Body ground
      Tester Range	2 V/DIV., 20 ms./DIV.
      Condition	Cranking

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      TEXT IN ILLUSTRATION
      
      

      *a	Component with harness connected (ECM)
      *b	FPD Terminal Waveform Normal Waveform

      Standard

      Signal waveform appears as shown in the illustration.

Result: 

OK 

REPLACE INJECTOR DRIVER (EDU) 

(Refer to REMOVAL [06/2016 - ] )

Result: 

NG 

REPLACE ECM 

(Refer to REMOVAL [06/2016 - ] )