April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pin Voltage Charts

Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the ECU determines whether it's receiving and transmitting proper voltage signals. Charts may also help determine if ECU harness is shorted or opened.

NOTE: Voltage readings may vary slightly due to battery condition or charging rate. All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in testing procedure.

Fig 1: Typical ECU Terminal Pin Connector

G121509

Courtesy of VOLKSWAGEN UNITED STATES, INC.

NOTE: Cabriolet voltage and resistance checks are not available from manufacturer.

Fig 2: ECU Voltage & Resistance (Fox)

G121518

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Fig 3: ECU Voltage & Resistance (Corrado)

G90A21907

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Fig 4: ECU Voltage & Resistance (Golf & Jetta CIS-E, 1 of 2)

G121519

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Fig 5: ECU Voltage & Resistance (Golf & Jetta CIS-E, 2 of 2)

G121520

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Fig 6: ECU Voltage & Resistance (Golf & Jetta Digifant II 1 of 2)

G50C17006

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Fig 7: ECU Voltage & Resistance (Golf & Jetta Digifant II 2 of 2)

G50D17007

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Fig 8: ECU Voltage & Resistance (Vanagon)

G90B21908

Courtesy of VOLKSWAGEN UNITED STATES, INC.