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Home >> Isuzu >> 2004 >> Axiom Base, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine DRIVEABILITY And Emissions - DTC P1237 To DTC U2104 >> DTC P1240: High Fuel Pressure Regulator Circuit Open >> Test Description

Test Description

  1. Refer to HIGH FUEL PRESSURE SYSTEM  section.
DTC P1240 - HIGH FUEL PRESSURE REGULATOR CIRCUIT OPEN

Step Action Values Yes No
1 Was the "On-Board Diagnostic (OBDII) System Check" performed? - Go to Step 2 Go to On-Board Diagnostic (OBD-II) System Check
2 Check the ECM Main Relay.
Was a problem found?		 - Go to Step 3 Go to Step 4
3 Replace the ECM Main Relay.
Is the action complete?		 - Verify repair -
4
  1. Ignition "OFF".
  2. Disconnect the ECM
  3. Disconnect the High pressure regulator harness connector from the High pressure regulator.
  4. Check the High pressure regulator harness between the ECM Main Relay and the high pressure regulator for the following condition:
    1. An open circuit.
Was the problem found?		 - Go to Step 6 Go to Step 5
5
  1. Ignition "OFF".
  2. Disconnect the ECM
  3. Disconnect the High pressure regulator harness connector from the High pressure regulator.
  4. Check the High pressure regulator harness between the ECM and the High pressure regulator for the following condition:
    1. An open circuit.
Was the problem found?		 - Go to Step 6 Go to Step 7
6 Replace faulty harness.
Is the action complete?		 - Verify repair -
7 Check the high pressure regulator circuit.
If a problem found repair or replace as necessary.
Was a problem found?		 - Verify repair Go to Step 8
8 Install the test ECM.
Program the test ECM (Immobilizer system). Refer to IMMOBILIZER SYSTEM .
Check the OBD-II test for following condition:
  1. When the ignition is "ON", turn on the MIL and RPL (RPL is put out after 3 seconds).
  2. When the engine is started.

Did the DTC disappear?		 - Go to Step 9 Go to Step 2
9 Replace the original ECM.
Check the poor connection between the ECM and ECM connector.
Recheck the OBD -II test again. When the engine is started.
Did the DTC disappear?		 - Verify repair Go to Step 10
10 Disconnect the ABS control unit connector.
Reprogramming the original ECM. (Engine control and Immobilizer control)
Recheck the OBD -II.
Did the DTC disappear?		 - Verify repair Go to Step 11
11 Replace the ECM.
Recheck the OBD -II test again.
Did the DTC disappear?		 - Verify repair Refer to Diagnostic Aids
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