GR-FE EINE CONTROL SYSTEM SFI SYSTEM 6 DTC P030 Fuel Pump Primary Circuit DCRIPTION In the diagram below, when the engine is cranked, current flows from terminal ST of the ignition switch into the ECM to the ST (starter) relay coil and also current flows to terminal ST of the ECM (ST signal). When the ST signal and NE signal are input to the ECM, Tr (power transistor ) 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 Tr ON (circuit opening 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 (ST ON), Tr (power transistor ) 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 operates at high speed. During idling or under light loads, Tr goes ON, and then power is supplied to the fuel pump via the fuel pump resistor. The fuel pump operates at low speed.
6 GR-FE EINE CONTROL SYSTEM SFI SYSTEM EFI EFI Relay ECM Fuel Pump Resistor MREL Circuit Opening Relay Fuel Pump Relay Tr Ignition IGN Fuel Pump LT M M M IG ST M IG ST ST Relay ST P N * * Park/Neutral Position * FC Tr * Clutch Start * ST attery Starter *: /T *: M/T Crankshaft Position Sensor (NE Signal) NE G0363E0 DTC No. DTC Detection Condition Trouble rea P030 Open or short in fuel pump relay circuit Open or short in fuel pump relay circuit Fuel pump relay ECM
GR-FE EINE CONTROL SYSTEM SFI SYSTEM 63 WIRI DIGRM Engine Room R/ ECM EFI Relay L 3 W-G 3 IC4 W-G 8 E8 MREL W- -O C J4 J/C C -O E 3 IGN C/OPN Relay Engine Room R/ D 6 6 IG Driver Side J/ I8 Ignition 3 GR- -W -W 33 0 GR- IC4 E8 FC EFI M 7 M Engine Room J/ attery R J J/C J3 W- E I 4 O F4 Fuel Pump 4 3 W- -Y Y- Fuel Pump Relay IC4 9 Y- F8 IM Fuel Pump Resistor J4 J40 Engine Room R/ J4 Y- J/C 30 L W- HINT: This DTC chart is on the premise that the engine is started normally. If the engine is difficult to start, proceed to the problem symptoms table (See page -0). G03683E0
64 GR-FE EINE CONTROL SYSTEM SFI SYSTEM INSPECTION PROCEDURE HINT: Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred. INSPECT ECM ( VOLTGE) ECM Connector Measure the voltage of the ECM connector. Standard voltage Tester Connection Condition Specified Condition (-30) - E (-) ST signal ON 9 to 4 V (-30) - E (-) ST signal OFF 0 to 3 V E (-) (+) REPLCE ECM E84E3 INSPECT FUEL PUMP RELY (b) Remove the fuel pump relay from the engine room R/. Measure the resistance of the fuel pump relay. Standard resistance 0309E0 Tester Connection Specified Condition 3-4 elow Ω 3-0 kω or higher 3-4 3-0 kω or higher (when battery voltage applied to terminals and ) elow Ω (when battery voltage applied to terminals and ) REPLCE FUEL PUMP RELY
GR-FE EINE CONTROL SYSTEM SFI SYSTEM 6 3 CHECK HRNS ND CONNECTOR (FUEL PUMP RELY - ECM) (b) (c) Remove the fuel pump relay from the engine room R/. Disconnect the ECM connector. Measure the resistance between wire harness side connectors. Standard resistance (Check for open) Tester Connections Specified Conditions ECM Connector Engine Room R/: Fuel pump relay () - (-30) Standard resistance (Check for short) Tester Connections Fuel pump relay () or (-30) - ody ground elow Ω Specified Conditions 0 kω or higher (d) (e) Reconnect the ECM connector. Reinstall the fuel pump relay. Fuel Pump Relay REPIR OR REPLCE HRNS OR CONNECTOR 3878E0 REPLCE ECM