Cabriolet V6-2.8L (AFC) (1995)
/Page-1224001.png)
Intake Manifold Change-Over Valve: Testing and Inspection
ELECTRICAL CHECK
-
Disconnect harness connector on intake manifold change-over valve -N156-.
Intake Manifold Change-over Valve Test
-
Measure valve resistance.
^
Specified value: 25-35 ohms
If specified value is not obtained:
-
Replace intake manifold change-over valve.
CHECKING BATTERY POSITIVE VOLTAGE (B+) SUPPLY
-
Disconnect harness connector on intake manifold change-over valve.
2-Pin Connector
-
Connect US 1115 LED tester or equivalent between harness connector terminal 1 (positive) and Ground (GND) using adapter from VW 1594
connector test kit.
-
Use On-Board Diagnostics (OBD) Output Diagnostic Test Mode (DTM) to activate fuel pump relay -J17-. See: Computers and Control
Systems/Testing and Inspection
^
LED must light up
If LED does not light up:
-
Check HO2S circuit breaker -S73- (brown holder in electronics box, passenger side footwell).
-
Check wiring for continuity between valve harness connector terminal 1 and circuit breaker using wiring diagram.
^
Specified reading: 0.5 ohms
-
Check fuel pump relay and activation.
CHECKING INTAKE MANIFOLD CHANGE-OVER VALVE ACTIVATION
-
Connect US 1115 LED tester or equivalent across terminals 1 and 2 of intake manifold change-over valve connector using adapter from VW
1594 connector test kit.
-
Use On-Board Diagnostics (OBD) Output Diagnostic Test Mode (DTM) to activate intake manifold change-over valve. See: Computers and
Control Systems/Testing and Inspection
^
LED must blink when intake manifold change-over valve is activated.
If LED does not blink or lights up continuously:
-
Connect VAG 1598 test box to ECM wiring harness for using adapter harness VAG 1598/11. Refer to Computer and Control Systems, System
Diagnosis, VAG 1598 Pin Out Box Connecting. See: Computers and Control Systems/Testing and Inspection/Scan Tool Testing and
Procedures/Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/31 Test Box
^
Adapter harness for ECM is not connected.
If LED lights up continuously:
