ECD SYSTEM, Diagnostic DTC:P1266

DTC Code DTC Name
P1266 Supply Pump Pressure Malfunction

DESCRIPTION


P1266
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Warm up the engine, race the engine so that the engine speed reaches 3000 rpm or more a few times, and then idle the engine for 17 minutes or more.

The pressure limiter valve remains open for 17 minutes or more due to the suction control valve being stuck open.

(1 trip detection logic)

  • Open or short in injection or supply pump assembly (suction control valve) circuit

  • Injection or supply pump assembly (suction control valve)

  • Fuel filter

  • Fuel pipe

  • ECM
Warm up the engine, and then race the engine at a speed 2000 rpm or higher for 20 seconds.

"Fuel Press" is lower than "Target Common Rail Pressure" by the specified amount or more for 20 seconds or more.

(1 trip detection logic)

Tech Tips


  • The pressure limiter valve is determined to be open when the suction control valve is stuck open.

  • Low fuel pressure indicates that "Fuel Press" cannot increase to the value of "Target Common Rail Pressure" for some reason. Usually, this is detected due to the injection or supply pump assembly not being able to pump an adequate amount of fuel due to a clogged fuel line, etc.

WIRING DIAGRAM

Refer to DTC P0088 Click here.

INSPECTION PROCEDURE

Note


  • After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

  • After replacing the injection or supply pump assembly, the ECM needs initialization Click here.

Tech Tips

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 moving or stationary, whether the engine was warmed up or not, as well as other data recorded at the time of a malfunction.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR


    1. Disconnect the suction control valve connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      E37-23 (PCV+) - S31-1 (SCV+) Always Below 1 Ω
      E37-12 (PCV-) - S31-2 (SCV-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      E37-23 (PCV+) or S31-1 (SCV+) - Body ground Always 10 kΩ or higher
      E37-12 (PCV-) or S31-2 (SCV-) - Body ground Always 10 kΩ or higher

    4. Reconnect the suction control valve connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  2. INSPECT SUCTION CONTROL VALVE


    1. Inspect the suction control valve Click here.


    NG

    CHECK FUEL INJECTION SYSTEM Click here

    OK

  3. INSPECT DIESEL FUEL FILTER ASSEMBLY


    1. Check that the fuel filter is not clogged.

      OK
      Fuel filter is not clogged.

    NG

    REPLACE DIESEL FUEL FILTER ASSEMBLY

    OK

  4. CHECK CLOGGED FUEL PIPE


    1. Check the clogged fuel pipe.


    NG

    REPAIR OR REPLACE FUEL PIPE

    OK

    REPLACE ECM Click here