Testing Intake Manifold Change-Over Valve -N156 - Audi A8 1994 Service Manual

Audi A8 1994 ➤
Motronic injection and ignition system (6-cylinder) - Edition 02.1999
Read measured value block 95
1 2 3
- Check display values for intake manifold change-over.
Display Group 95: Intake manifold change-over at idling speed
Display xxx rpm
Indicates Engine speed
(in steps of 40 rpm)
Range min.: 550 rpm
max.: 6800 rpm
Specification 650...750 rpm
Note
- Check readout in display zone 4.
Specification: IMC-V OFF
- Increase engine speed to about 4700 rpm (display zone 1) and observe readout in display zone 4.
- The intake manifold change-over function should be activated (display zone 4).
Display Group 95: Intake manifold change-over with vehicle being driven
Display xxxx rpm
Indicates Engine speed
(in steps of 40 rpm)
Range min.: 550 rpm
max.: 6800 rpm
Specification 4500...6800 rpm
Note
- If the display shows "Stage 1" but the vacuum unit for the intake manifold change-over is not activated (fitting
location: on front left of intake manifold):
- Test intake manifold change-over valve
=> Page 64
- Check vacuum system for leaks
=> Page 67

3.3 - Testing intake manifold change-over valve -N156

Fitting location=>Page
Testing intake manifold change-over valve -N156
- Run engine at idling speed for 2 or 3 minutes to build up vacuum.
- Switch engine off.
- Switch ignition on.
-> Perform final control diagnosis and activate intake manifold change-over valve
64
24 - Mixture preparation, Injection
4
1 2
x.xx ms
Load
min.: 0.00 ms
max.: 100.00 ms
12.0... 26.0 ms
1 2
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permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
x.xx ms
with respect to the correctness of information in this document. Copyright by AUDI AG.
Load
min.: 0.00 ms
max.: 120.00 ms
16.0...120.00 ms
23 .
Display zones
3
xxx.x ° C
Coolant temperature
80.0...105.0 ° C
Display zones
3
xxx.x ° C
Coolant temperature
80.0...105.0 ° C
4
IMC-V OFF
Intake manifold change-over
IMC-V OFF
Stage 1
IMC-V OFF
4
Stage 1
Intake manifold change-over
IMC-V OFF
Stage 1
Stage 1