How to test intake manifold resonance electric change-over valve?
09-20-2012, 12:24 PM
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How to test intake manifold electric change-over valve?
Vehicle: c280 1998
Intake vacuum is 18 to 20 and the vacuum hose connects to electric change-over valve (part 41 - see diagram). I get no vacuum on the electric change-over valve output port regardless of the engine rpm (<1000 to >4000).
I think that electric change-over valve should open while parked or driving and if the engine is above 4000-rpm.
In park test results:
Electric change-over valve resistance: 32 Ohms
From connector's contact 1 (positive) to ground while engine on: 12v
From connector's contact 1 (positive) to ground while engine off: 0v
From connector's contact 1 (positive) to contact 2 (ground from ECU) while engine on and in park: 6-8v at all times regardless of the engine RPM
From connector's contact 2 (ground from ECU) to battery ground while in park and with rpm above 4000: NOTHING
Driving test results:
1.) Disconect connector from the intake change-over valve
2.) Got a long wires (2) and strip the ends in order to slide each end inside connector to establish proper contacts on contact 1 & 2
3.) Conect voltmeter to the other ends (+-)
4.) Drive the car on highway at least 3500-4200rpms
VOLTAGE: 6-8V AT ALL TIMES
I think the 12v is supplied at all times, but the ground is electronically activated by the ECU unit.
So, the ECU is not sending the ground!
Any advise will be appreciated. Thanks!!!
Intake vacuum is 18 to 20 and the vacuum hose connects to electric change-over valve (part 41 - see diagram). I get no vacuum on the electric change-over valve output port regardless of the engine rpm (<1000 to >4000).
I think that electric change-over valve should open while parked or driving and if the engine is above 4000-rpm.
In park test results:
Electric change-over valve resistance: 32 Ohms
From connector's contact 1 (positive) to ground while engine on: 12v
From connector's contact 1 (positive) to ground while engine off: 0v
From connector's contact 1 (positive) to contact 2 (ground from ECU) while engine on and in park: 6-8v at all times regardless of the engine RPM
From connector's contact 2 (ground from ECU) to battery ground while in park and with rpm above 4000: NOTHING
Driving test results:
1.) Disconect connector from the intake change-over valve
2.) Got a long wires (2) and strip the ends in order to slide each end inside connector to establish proper contacts on contact 1 & 2
3.) Conect voltmeter to the other ends (+-)
4.) Drive the car on highway at least 3500-4200rpms
VOLTAGE: 6-8V AT ALL TIMES
I think the 12v is supplied at all times, but the ground is electronically activated by the ECU unit.
So, the ECU is not sending the ground!
Any advise will be appreciated. Thanks!!!
Last edited by yunet; 09-20-2012 at 10:19 PM.
06-29-2019, 05:03 AM
#2
MBWorld Fanatic!
Having the same error with y22/6 - intake manifold switchover valve short
car runs strong, but I feel like it’s lost maybe 5% power at low RPMs?
car runs strong, but I feel like it’s lost maybe 5% power at low RPMs?
