[2] Check component Y27/9 (Left EGR positioner).: Short circuit to ground

[2] Check component Y27/9 (Left EGR positioner).: Short circuit to ground


Possible cause:

- Y27/9 (Left EGR positioner)
Affected functions:

- Engine diagnosis

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Test 1: Check component Y27/9 (Left EGR positioner).

1. Check component Y27/9 (Left EGR positioner).

Test 1.1: Check component Y27/9 (Left EGR positioner) using actual value.

Test 1.2: Check component Y27/9 (Left EGR positioner) by means of actuation.

Test 1.3: Check power supply of component Y27/9 (Left EGR positioner).

Test 1.4: Automatic test of exhaust gas recirculation

1.1. Check component Y27/9 (Left EGR positioner) using actual value.
Test prerequisites

- Coolant temperature > 20° C
- Operate engine at idling speed.
- Briefly blip throttle.
- When the idle speed is reached again, the actual values must be within the specified value ranges for a period of approx. 180 s.
Communication with ECU required

1.2. Check component Y27/9 (Left EGR positioner) by means of actuation.
Warning!Communication with ECU required.


1.3. Check power supply of component Y27/9 (Left EGR positioner).
Check power supply of component Y27/9 (Left EGR positioner).
Figure legend

- Y27/9 (Left EGR positioner)
Test prerequisite

- The actuation was not okay.
Test sequence

- Switch off ignition.
- Detach coupling at component Y27/9 (Left EGR positioner).
- Measure direct voltage with multimeter between sockets (Y27/9x1) 3 and (Y27/9x1) 2
- Switch on ignition.
Specified value

- Voltage[11...14]V
Question

- Is the measurement value OK?







YES
Test signal cable to component N3/9 (CDI control unit).
Figure legend

- Y27/9 (Left EGR positioner)
Special tools

- Test cable 266 589 01 63 00
- Socket box 129 589 00 21 00
Test sequence

- Switch off ignition.
- Connect 126-pole socket box at engine wiring harness.
- Measure resistance with multimeter between socket (M.71) 71 of the 126-pole socket box tester and (Y27/9) 1
Specified value

- Resistor< 1ohms
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further procedure

- If faults with high fault frequency counters or customer complaints are stored, inspect cables and plug connections between control module N3/9 (CDI control unit) and component Y27/9 (Left EGR positioner) for loose contact and corrosion.
- Replace component Y27/9 (Left EGR positioner).
End of test

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

- Inspect cables, electrical connections and plug connections for damage, correct connection, loose contact and corrosion, and repair or replace if necessary.
End of test

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

- Test wiring of voltage supply between component Y27/9 (Left EGR positioner) and component N3/9 (CDI control unit).
End of test

1.4. Automatic test of exhaust gas recirculation
Automatic test of exhaust gas recirculation
Test prerequisites:Coolant temperature between 80 °C and 100 °COil temperature between 80 °C and 100 °C Lambda value between 1 and 10All electrical accessories must be switched off.Switch off the air conditioning.Intake and exhaust system without leakage; Operate parking brake.Take out gear.Engine at idle. Status of the relevant actual values:
- Coolant temperature:Warning! Communication with ECU required.

- Oil temperature:Warning! Communication with ECU required.

- Lambda value:Warning! Communication with ECU required.
Continue with button F2