LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Volkswagen >> 1991 >> Jetta GLI, 2.0 J >> Repair and Diagnosis >> Engine Performance >> Engine Controls - Pin Voltage Charts >> Pin Voltage Charts
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pin Voltage Charts

ECU PIN VOLTAGE (DIGIFANT I) - ECU CONNECTED TO VAG 1598

Terminals Component To Be Tested & Condition Specification
13 & 14 Voltage Supply (Control Unit), Ign. ON Battery Voltage
14 & 19 Voltage Supply (Control Unit), Ign. ON Battery Voltage
3 & 13 (Jumper) Wires To Fuel Pump Relay, Ignition ON Pumps Must Run Audibly
1 & 25 (M/T) Wires From Starter Terminal 50 Ign. OFF, Operate Starter 8 Volts Minimum
19 & 34 (M/T) Ground To Pin No. 34, Ignition OFF Battery Voltage
19 & 25 (A/T) Wiring To Starter Lockout Relay Ignition ON, Select "P" Then "N" Battery Voltage
Wiring To Starter Lockout Relay, Ign. ON Select "1", "2", "3", "D" & "R" No Voltage
34 & 35 (A/T) Wiring To Starter Lockout Relay, Select "P", Operate Starter Less Than Battery Voltage
1 & 19 Voltage To Control Unit, Ignition On Battery Voltage
19 & 35 Voltage To Control Unit, Ignition On Battery Voltage
1 & 6 Wires To Coil, Ignition On Battery Voltage
1 & 4 Fault Indicator Light, Ignition On Battery Voltage
1 & 23 Idle Stabilizer Valve, Ignition On Battery Voltage
1 & 24 (Jumper) Wires To Fuel Pump Relay, Ignition On Pumps Must Run Audibly
1 & 20 Wiring To Injector - Cyl. No. 1 (1) Battery Voltage
1 & 21 Wiring To Injector - Cyl. No. 2 (1) Battery Voltage
1 & 3 Wiring To Injector - Cyl. No. 3 (1) Battery Voltage
1 & 2 Wiring To Injector - Cyl. No. 4 (1) Battery Voltage
33 & 19 A/C Compressor ON, Jumper Terminals, DO NOT Use Multimeter Click From Comp. Clutch
28 & 34 Throttle Potentiometer (Power), Ign. ON 4.5-5.0 Volts
33 & 28 Throttle Potentiometer, Connect Potentiometer, Ignition On Throttle Setting: Idle 0.3-1.7 Volts
Throttle Potentiometer, Connect Potentiometer, Ignition On Throttle Setting: Full Throttle 3-5 Volts
28 & 38 Hall Sender (Power), Ignition ON 10 Volts Min.
37 & 38 Hall Sender (Signal), (2) Ignition OFF Operate Starter LED Must Flicker
1 & 6 Ignition Signal Function, (2) Ignition Off Operate Starter LED Must Flicker
(1) With Ignition ON and fuse No. 18 removed, jump terminals No. 1 and 24 together.
(2) Perform test only if engine will not start. Turn ignition off. Instead of multimeter, connect LED Tester (US 1115) using Adapter Kit (VW 1594). Disconnect harness from rail (main injector connector).
ECU PIN VOLTAGE (DIGIFANT I) - ECU NOT CONNECTED TO VAG 1598

Terminals Component To Be Tested & Condition Specification
1 & 2 Control Unit Voltage & Ground Connection Ignition ON Battery Voltage
1 & 2 Voltage Supply, Ignition OFF, Operate Starter 8 Volts Minimum
2 & 3 Power Supply Wires, Ignition ON Battery Voltage
2 & 4 Power Supply Wires, Ignition ON Battery Voltage
2 & 5 Ignition ON, Operate Full Throttle Switch Battery Voltage
2 & 13 Ignition ON, Operate Throttle Idle Switch Battery Voltage
2 & 6 With A/C Ignition & A/C On Battery Voltage
2 & 16 With A/C Ignition & A/C On Battery Voltage
2 & 19 With A/C Ignition & A/C On Battery Voltage
2 & 24 With A/C Ignition Off, Operate Starter 8 Volts Minimum
2 & 25 With A/C Hall Sender (Signal), (1) Ignition Off, Operate Starter LED Must Flicker
(1) Connect LED Tester (US 1115) instead of DVOM (US 1119).
VOLTAGE CHECKS (DIGIFANT II) - ECU NOT CONNECTED TO VAG 1598

Terminals Component To Be Tested & Condition Specification
13 & 14 Voltage Supply To Control Unit, Ign. On Battery Voltage
14 & 19 Voltage Supply To Control Unit, Ign. On Battery Voltage
1 & 13 Wire To Starter Term. 50, Operate Starter 8 Volts Minimum
12 & 14 Circuit To Fuel Injectors, Ign. Off 3.7-5.5 Ohms
5 (1) & 14 Circuit To Fuel Injectors, 5-Pin, Connector Disconnected 3.7-5.5 Ohms
6 (1) & 5 Hall Control Unit Circuit, Harness Connector Disconnected .5 Ohm Maximum
6 & 10 Coolant Temperature Sensor, (2) (2)
6 & 11 Idle/Full Throttle Switch, Throttle Closed .5 Ohm Maximum
Idle/Full Throttle Switch, Throttle Partly Open Infinity
Idle/Full Throttle Switch, Throttle Fully Open .5 Ohm Maximum
6 & 17 Airflow Potentiometer, Ign. Off 500-1000 Ohms
17 & 21 Airflow Potentiometer, Move Airflow Sensor Flap Or Operate Starter Change In Resistance
6 & 9 Intake Air Temp. Sensor, (2) (2)
3 & 13 (Jumper) Fuel Pump Relay Circuit, Ign. On Fuel Pump Must Operate
6 & 8 Hall Sender Circuit, (3) Harness Connector Disconnected .5 Ohm Maximum
6 & 18 Hall Sender Circuit, (2) Harness Connector Disconnected .5 Ohm Maximum
4 & 5 Knock Sensor Circuit, (2) Harness Connector Disconnected .5 Ohm Maximum
4 & 7 Knock Sensor Circuit, (2) Harness Connector Disconnected .5 Ohm Maximum
22 & 23 Idle Stabilizer Circuit, Ign. Off 2-10 Ohms
13 & 16 A/C Compressor Wiring, (3) .5 Ohm Maximum
2 & 13 O2 Sensor Circuit, O2 Harness Connector .5 Ohms Maximum
Disconnected & Grounded 3-Pin Term. No. 1 & 2 Jumpered Infinity
(1) Terminal number indicated is the component's connector terminal number and not of ECU or Test Box.
(2) Harness connector disconnected and all 3 harness connector terminals jumpered.
(3) Harness connector, located near brake booster, disconnected and Green wire jumpered to ground.
VOLTAGE CHECKS (DIGIFANT II) - ECU CONNECTED TO VAG 1598

Terminals (1) Component To Be Tested & Condition Specification
6 & 8 Voltage Supply To Hall Sender, Ign. On 10 Volts Minimum
6 & 18 (2) Signal From Hall Sender, Operate Starter LED Must Flicker
13 & 25 (2) ECU Ign. Switching Function, Operate Starter LED Must Flicker
(1) Terminal number indicated is the component's connector terminal number and not of ECU or Test Box.
(2) Connect LED Tester (US 1115) to test box instead of DVOM (US 1119).
scientia non olet · About LEMON Manuals