Electronic Control System Gas Plus Engines – 019-351   Fuel Control Valve Circuit

Disconnect engine harness ECM connector 1 from the ECM. Disconnect the fuel control valve from the engine harness. Set the multimeter to measure resistance.

Measure the resistance from the fuel control valve (+) pin in the engine harness ECM connector to the corresponding pin in the engine harness valve connector.

The multimeter must show a closed circuit (10 ohms or less).

If the circuit is not closed, there is an open circuit in the fuel control valve (+) wire.

Repair or replace the engine harness. Refer to Procedure 019-205, 019-204, or 019-043.

Measure the resistance from the fuel control valve (-) pin in the engine harness ECM connector to the corresponding pin in the engine harness valve connector.

The multimeter must show a closed circuit (10 ohms or less).

If the circuit is not closed, there is an open circuit in the fuel control valve (-) wire. Repair or replace the engine harness. Refer to Procedure 019-205, 019-204, or 019-043.

Disconnect engine harness ECM connector 1 from the ECM. Disconnect the fuel control valve from the engine harness. Set the multimeter to measure resistance.

Measure the resistance from the fuel control valve (+) pin in the engine harness ECM connector to engine block ground.

The multimeter must show an open circuit (100k ohms or more).

If the circuit is not open, there is a short circuit to ground in the fuel control valve (+) wire.

Repair or replace the engine harness. Refer to Procedure 019-204, or 019-043.

Measure the resistance from the fuel control valve (-) pin in the engine harness ECM connector to engine block ground.

The multimeter must show an open circuit (100k ohms or more).

If the circuit is not open, there is a short circuit to ground in the fuel control valve (-) wire. Repair or replace the engine harness. Refer to Procedure 019-204, or 019-043.

Disconnect engine harness ECM connectors 1 and 2 from the ECM. Disconnect the fuel control valve from the engine harness. Set the multimeter to measure resistance.

Measure the resistance from the fuel control valve (+) pin in engine harness ECM connector 1 to all other pins in the connector.

Repeat the pin-to-pin check from the fuel control valve (-) pin in engine harness ECM connector 1 to all other pins in the connector.

The multimeter must show an open circuit at all pins.

If any pin-to-pin check does not show an open circuit, there is a short circuit between the applicable pins.

Repair or replace the engine harness. Refer to Procedure 019-204, or 019-043.

Measure the resistance from the fuel control valve (+) pin in engine harness ECM connector 1 to all pins in engine harness ECM connector 2.

Repeat the pin-to-pin check from the fuel control valve (-) pin in engine harness ECM connector 1 to all pins in engine harness ECM connector 2.

If any pin-to-pin check does not show an open circuit, there is a short circuit between the applicable pins.

Repair or replace the engine harness. Refer to Procedure 019-204, or 019-043.