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System Diagnosis

On California models equipped with Digifant II system, an "On-Board Diagnostic System" is used. Trouble codes/fault memory can be read through the "Check" indicator switch which illuminates when a fault is detected and stored in memory or by activating fault memory. To activate fault memory/code(s), turn ignition switch to "ON" position, engine off. Depress "Check" indicator switch for at least 4 seconds. Indicator light on switch will start flashing codes. A flash code consists of 4 flash impulse groups, with a maximum of 4 flash impulse per group. Between each impulse group there is a 2.5 second pause between codes.

To erase fault codes from memory, turn ignition switch to "OFF" position, press and hold down indicator switch and turn ignition switch to "ON" position. Continue depressing switch for about 5 seconds and turn ignition switch off. Test drive vehicle for a minimum of 10 minutes. Recheck codes and correct if necessary. Repeat fault erasing procedure until memory is cleared.

FAULT/TROUBLE CODES - DIGIFANT II

Flash Code Circuit Affected
2312 Coolant Temperature Sensor
2322 Intake Air Temperature Sensor
2232 Airflow Sensor Potentiometer
2142 Knock Sensor
2342 Oxygen Sensor
4444 No Fault(s) in Memory
0000 End of Test Sequence
Fig 1: ECU Connector Pin Location
G62165Courtesy of VOLKSWAGEN UNITED STATES, INC.
GOLF, GOLF GT & JETTA AFC DIGIFANT SYSTEM RESISTANCE CHECKS (1)

Terminals Components Checked Specifications
No. 12 & No. 14 Injectors 15-20 ohms with only 1 injector connected
No. 6 (2) & No. 11 Throttle Valve Switch (Idle & Full) 0 ohms at idle & full throttle
No. 2 & No. 13 Oxygen Sensor 0 ohms with O2 sensor disconnected & grounded/infinity with sensor connected
No. 6 (2) & No. 17 Airflow Meter Approximately 500-1000 ohms
No. 21 & No. 17 Airflow Meter Ohms varies when moving air sensor
No. 6 (2) & No. 8/No. 6 (2) & No. 18 Hall Sender Wiring Continuity should exist w/sensor removed & all 3 connectors jumped together
No. 4 & No. 5/No. 4 & No. 7 Knock Sensor Continuity should exist w/sensor removed & all 3 connectors jumped together
No. 22 & No. 23 Idle Stabilizer Continuity
No. 16 & No. 13 A/C Compressor Continuity should exist w/Green wire on brake booster grounded
(1) Resistance checks are performed with ignition OFF. To prevent electrical damage, only check terminals listed.
(2) NEVER connect test light to this terminal if multi-pin plug is connected to ECU.
GOLF, GOLF GT & JETTA AFC DIGIFANT SYSTEM VOLTAGE CHECKS (1)

Terminals Components Checked Specifications
No. 13 & No. 14/No. 14 & No. 19 ECU Voltage Supply About battery voltage
No. 13 & No. 25 To Ignition Coil Term. 1 About battery voltage
No. 1 & No. 13 Voltage to Idle Stabilizer Pull injector plugs off. Cranking voltage should be present when cranking engine
No. 3 & No. 13 Fuel Pump Relay Place jumper wire across terminals. Turn ignition on and fuel pump must run
(1) All system checks are performed with ignition ON.
VANAGON AFC DIGIFANT SYSTEM RESISTANCE CHECKS (1)

Terminals Components Checked Specifications
No. 12 & No. 14 Injectors Connect only one injector at a time. 15-20 ohms
No. 6 (2) & No. 11 Throttle Valve Switch Continuity when closed or fully open
No. 6 (2) & No. 17 Intake Air Sensor 500-1000 ohms
No. 17 & No. 21 Intake Air Sensor Resistance changes when moving air sensor plate
No. 6 (2) & No. 8/No. 6 (2) & No. 18 Hall Sender Wiring Continuity should exist with Hall sender removed and all 3 connectors jumped together
No. 2 & No. 13 Oxygen Sensor Wiring Continuity should exist with connector removed from oxygen sensor and Green wire grounded. No continuity with connector installed
(1) All system checks performed with ignition OFF and ambient temperature of 32-104°F (0-40°C).
(2) NEVER connect test light to this terminal if multi-pin plug is connected to ECU.
VANAGON AFC DIGIFANT SYSTEM VOLTAGE CHECKS (1)

Terminals Components Checked Specifications
No. 13 & No. 14/No. 14 & No. 19 Control Unit Voltage Supply Approximate battery voltage
No. 13 & No. 25 Voltage To Ignition Coil Terminal No. 1 Approximate battery voltage
No. 1 & No. 13 Voltage To Idle Stabilizer Unplug all 4 injectors. Voltage at starter terminal No. 50 when cranking should be minimum 8 volts
No. 3 & No. 13 Voltage To Fuel Pump Relay Connect jumper wire between terminals. Fuel pump should operate
(1) All system checks performed with ignition on and ambient temperature of 32-104°F (0-40°C).
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