LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Volkswagen >> 1987 >> Quantum Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> BOSCH Cis-E System >> Testing >> Electrical Components >> Fuel Pump Relay - 4-Cylinder Models
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Fuel Pump Relay - 4-Cylinder Models

NOTE: No testing procedure was available from manufacturer for 5-cylinder Volkswagen models.
  1. Remove fuel pump relay from relay board. Turn ignition on. Using multimeter, measure voltage at following relay board sockets: between terminal No. 2 and ground, between terminals No. 2 and 1 and between terminals No. 4 and 1. Reading should be battery voltage or slightly less.
  2. If reading is low or zero, check wiring. Refer to WIRING DIAGRAMS  to check circuits. Measure voltage between relay board sockets No. 5 and 1. Battery voltage should be present. If reading is correct, ground middle wire of ignition distributor connector.
  3. Voltage reading should drop for short time. If reading does drop, replace relay. Reading should be battery voltage or slightly less.
  4. If reading is low or zero, check wiring. Refer to WIRING DIAGRAMS  to check circuits. Measure voltage between relay board sockets No. 5 and 1. Battery voltage should be present. If reading is correct, ground middle wire of ignition distributor connector.
  5. Voltage reading should drop for short time. If reading does drop, replace fuel pump relay and check Hall sender. If reading does not drop, check Hall ignition ECU.
scientia non olet · About LEMON Manuals