P0230

2GR-FE ENGINE CONTROL: SFI SYSTEM: P0230: Fuel Pump Primary Circuit
P0230 - Fuel Pump Primary Circuit

DESCRIPTION

As shown in the illustration, when the engine is cranked, current flows from the terminal ST1 of the ignition switch into the ECM and the ST (starter) relay coil and also current flows to terminal STA of the ECM (STA signal).

When the STA signal and NE signal are input to the ECM, Tr1 (power transistor 1) is turned ON, current flows to the coil of the circuit opening relay, the relay switches on, power is supplied to the fuel pump, and the fuel pump operates.

While the NE signal is generated (engine running), the ECM keeps the Tr1 ON (C/OPN relay ON) and the fuel pump also keeps operating.

The fuel pump speed is controlled at two levels (high speed or low speed) by engine condition (starting, light load, heavy load). When the engine starts (STA ON), Tr2 (power transistor 2) in the ECM is OFF, so the fuel pump relay closes and positive battery voltage is applied directly to the fuel pump. The fuel pump operated at high speed.

During idling or under light loads, Tr2 goes ON, and then power is supplied to the fuel pump via the fuel pump resistor. The fuel pump operates at low speed.









WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
This troubleshooting procedure is based on the premise that the engine can start. If the engine cannot start, proceed to Problem Symptoms Table Symptom Related Diagnostic Procedures.

PROCEDURE

1. INSPECT F/PMP RELAY

(a) Remove the F/PMP relay from the engine room relay block.

(b) Inspect the F/PMP relay Testing and Inspection.

(c) Reinstall the F/PMP relay.

NG -- REPLACE F/PMP RELAY
OK -- Continue to next step.

2. CHECK TERMINAL VOLTAGE (F/PMP RELAY)

(a) Remove the F/PMP relay from the engine room relay block.





(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





(c) Reinstall the F/PMP relay.

NG -- CHECK FUEL PUMP CONTROL CIRCUIT Component Tests and General Diagnostics
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (F/PMP RELAY - ECM)

(a) Remove the F/PMP relay from the engine room relay block.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the ECM connector.

(e) Reinstall the F/PMP relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal