Electronic Control System Gas Plus Engines – 019-123   Throttle Actuator Circuit

Disconnect the throttle actuator from the engine harness. Disconnect engine harness ECM connector 1 from the ECM. Set the multimeter to measure resistance.

Measure the resistance from the throttle actuator (+) pin in the throttle actuator harness connector to the throttle actuator (+) pin in engine harness ECM connector 1. The multimeter must show a measurement of 10 ohms or less (closed circuit). If the circuit is not closed, repair or replace the engine harness. Refer to Procedure 019-201, 019-204 or 019-043.

Repeat the resistance check from the throttle actuator (-) pin in the throttle actuator harness connector to the throttle actuator (-) pin in the engine harness ECM connector. Then, measure the resistance from the throttle position (+) pin in the throttle actuator harness connector to the throttle position (+) pin in engine harness ECM connector 1.

The multimeter must show a measurement of 10 ohms or less (closed circuit). If the circuit is not closed, repair or replace the engine harness. Refer to Procedure 019-201, 019-204 or 019-043.

Disconnect the 31-pin OEM connector. Measure the resistance from the switched battery (+) pin in the throttle actuator harness connector to the switched battery (+) pin in the 31-pin OEM connector, engine harness side.

The multimeter must show a measurement of 10 ohms or less (closed circuit). If the circuit is not closed, repair or replace the engine harness. Refer to Procedure 019-208, 019-201 or 019-043.

Measure the resistance from the throttle actuator (-) pin in the 31-pin connector, engine harness side, to the throttle actuator (-) pin in engine harness ECM connector 1. Repeat the resistance check from the ECM end of harness to the 31-pin end of the harness, between the throttle position (-) pins, and between the battery (-) pins. The multimeter must show a measurement of 10 ohms or less (closed circuit) at each return pin resistance check. If the circuit is not closed, repair or replace the engine harness. Refer to Procedure 019-208,019-204 or 019-043.

Disconnect the throttle actuator from the engine harness. Disconnect engine harness ECM connector 1 from the ECM. Disconnect the engine harness from the OEM harness at the 31-pin OEM connector. Set the multimeter to measure resistance.

Measure the resistance from the throttle actuator (+) pin in the throttle actuator harness connector to engine block ground. The multimeter must show a measurement of 100k ohms or more (open circuit). If the circuit is not open, repair or replace the engine harness. Refer to Procedure 019-201 or 019-043.

Check the other throttle actuator circuit pins in the throttle actuator harness connector. Repeat the short-to-ground check from the throttle actuator (-) pin to ground, the throttle position (+) pin to ground, and the switched battery (+) to ground.

The multimeter must show a measurement of 100k ohms or more (open circuit) at each short-to-ground check. If the circuit is not open, repair or replace the engine harness. Refer to Procedure 019-201 or 019-043.

Measure the resistance from the switched battery (+) pin in the 31-pin OEM connector to engine block ground.

The multimeter must show a measurement of 100k ohms or more (open circuit).

If the circuit is not open, repair or replace the OEM harness. Refer to the OEM manual.

Measure the resistance from the throttle actuator (+) pin in the engine harness ECM connector to engine block ground. Repeat the short-to-ground check from the throttle actuator (-) pin to ground, the throttle position (+) pin to ground, and the switched battery (+) pin to ground.

The multimeter must show a measurement of 100k ohms or more (open circuit) at each short-to-ground check. If the circuit is not open, repair or replace the engine harness. Refer to Procedure 019-204 or 019-043.

Disconnect the throttle actuator from the engine harness. Disconnect both engine harness ECM connectors from the ECM. Disconnect the engine harness from the OEM harness at the 31-pin OEM connector. Set the multimeter to measure resistance.

Measure the resistance from the switched battery (+) pin in the 31-pin OEM connector, OEM side, to all other pins in the connector. The multimeter must show a measurement of 100k ohms or more (open circuit) at all pins. If the circuit is not open, repair or replace the OEM harness. Refer to the OEM manual.

Measure the resistance from the throttle actuator (+) pin in engine harness ECM connector 1 to all other pins in the connector. Repeat the short-pin-to-pin check from the throttle actuator (-) pin to all other pins in the connector.

The multimeter must show a measurement of 100k ohms or more (open circuit) at each pin. If the circuit is not open, repair or replace the engine harness. Refer to Procedure 019-204 or 019-043.

Measure the resistance from the throttle position (+) pin in engine harness ECM connector 1 to all other pins in the connector. The multimeter must show a measurement of 100k ohms or more (open circuit) at all pins. If the circuit is not open, repair or replace the engine harness. Refer to Procedure 019-204 or 019-043.

Measure the resistance from the throttle actuator (+) pin in engine harness ECM connector 1 to all pins in engine harness ECM connector 2. Repeat the short-pin-to-pin check from the throttle actuator (-) pin in engine harness ECM connector 1 to all pins in engine harness ECM connector 2, and from the throttle position (+) pin in connector 1 to all pins in connector 2.

The multimeter must show a measurement of 100k ohms or more (open circuit) at all pins. If the circuit is not open, repair or replace the engine harness. Refer to Procedure 019-204 or 019-043.