P0004

The signal of the fuel pressure sensor for the low pressure circuit is implausible.

Test 1: Check component B4/7 (Fuel pressure sensor).

Test 2: Possible cause:

- B4/7 (Fuel pressure sensor)
Affected functions:

- Engine diagnosis
- Fuel system

1. Check component B4/7 (Fuel pressure sensor).

Test 1.1: Check component B4/7 (Fuel pressure sensor) using actual value.

Test 1.2: Check power supply of component B4/7 (Fuel pressure sensor).

Test 1.3: Test wiring to component B4/7 (Fuel pressure sensor).

1.1. Check component B4/7 (Fuel pressure sensor) using actual value.
Figure legend

- 043Pressure gage(103 589 00 21 00)
- 055Measuring beaker
- 069Pressure hose(119 589 04 63 00)
Preparation for test

- Switch off ignition.
- Connect test pressure gauge.
- Operate engine at idling speed.
Start check with button F2.







Warning!Communication with ECU required.


1.2. Check power supply of component B4/7 (Fuel pressure sensor).
Test prerequisite

- The actual value is not o.k.
Test sequence

- Switch off ignition.
- Unplug connector of pressure sensor B4/7 (Fuel pressure sensor).
- Measure direct voltage with multimeter between sockets (B4/7) 3 and (B4/7) 1
- Switch on ignition.
Specified values

- Voltage : [4.8 ... 5.3] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further possible causes of fault

- Inspect plug connections for corrosion, pinched insulation and loose contact.
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Test wiring of voltage supply between component N118 (Fuel pump control module) and component B4/7 (Fuel pressure sensor).
- Inspect plug connections for corrosion, pinched insulation and loose contact.
End of test

1.3. Test wiring to component B4/7 (Fuel pressure sensor).
Test prerequisite

- The actual value is not o.k.
Test sequence

- Switch off ignition.
- Unplug 8-pin connector from control module N118 (Fuel pump control module).
- Disconnect connector at component B4/7 (Fuel pressure sensor).
Open circuit

- (N118) 2.Measure resistance with multimeter between sockets 6 and 3 (B4/7)
- (N118) 2.Measure resistance with multimeter between sockets 7 and 2 (B4/7)
- (N118) 2.Measure resistance with multimeter between sockets 8 and 1 (B4/7)
- Specified values
- Resistors< 1ohms
-
Short circuit

- Test cable to component B4/7 (Fuel pressure sensor) for short circuit to each other.
- N118.2.6
- N118.2.7
- N118.2.8
- Specified values
- Resistorsinfiniteohms
-
Question

- Was the test o.k.?







YES
The measurement value is OK.Further possible causes of fault

- Inspect plug connections for corrosion, pinched insulation and loose contact.
- Replace component B4/7 (Fuel pressure sensor).
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Repair / replace faulty wiring between N118 (Fuel pump control module) and B4/7 (Fuel pressure sensor)
End of test

2. No further information available.