90CS Quattro V6-2.8L (AFC) (1995)
Canister Purge Regulator Valve: Testing and Inspection
CHECKING THE CANISTER PURGE REGULATOR VALVE
NOTE:
For functional testing of Evaporative Emission Control (EVAP) canister purge regulator valve activation, also see On-Board Diagnostics,
"Read Measuring Value Block" function 08. See: Computers and Control Systems/Testing and Inspection
ELECTRICAL CHECK
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Disconnect harness connector on EVAP canister purge regulator valve.
EVAP Canister Purge Regulator Valve Test
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Measure valve resistance.
^
Specified value: 20-28 ohms
If specified values are not obtained:
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Replace EVAP canister purge regulator valve.
CHECKING BATTERY POSITIVE VOLTAGE (B+) SUPPLY
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Disconnect harness connector on valve.
2-Pin Connector
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Connect VAG 15278 voltage tester between connector terminal 1 and Ground (GND) using cable from VW 1594 test kit.
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Use On-Board Diagnostics (OBD) output diagnostic test mode (DTM) to activate fuel pump relay.
^
LED must light up
If LED does not light up, perform following tests:
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Check the Heated Oxygen Sensor (HO2S) circuit breaker -S73- (brown holder in electronics box, passenger side footwell)
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Check continuity in wiring from terminal 1 of connector on EVAP canister purge regulator valve to circuit breaker using wiring diagram.
^
Specified reading: maximum 0.5 ohms
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Check fuel pump relay and activation.
CHECKING EVAP CANISTER PURGE REGULATOR VALVE ACTIVATION
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Connect US 1115 LED tester or equivalent to EVAP canister purge regulator valve connector terminals 1 and 2 using adapters from VW 1594
connector test kit.
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Use DTM to activate EVAP canister purge regulator valve.
^
LED must blink
If LED does not blink or lights up continuously:
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Connect VAG 1598 test box to ECM wiring harness using VAG 1598/12 adapter. 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