Engine Control System - SFI System

3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0560: System Voltage

DTC P0560 - System Voltage

DESCRIPTION

The battery supplies electricity to the ECM (Included in HV control ECU) even when the ignition switch is off. This power allows the ECM to store data such as DTC history, freeze frame data and fuel trim values. If the battery voltage falls below a minimum level, these memories are cleared and the ECM determines that there is a malfunction in the power supply circuit. When the engine is next started, the ECM will illuminate the MIL and set the DTC.





HINT: If DTC P0560 is set, the ECM (Included in HV control ECU) does not store other DTCs.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: Read freeze frame data using Techstream. The ECM (Included in HV control ECU) records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.

PROCEDURE

1. CHECK FUSE (IGCT NO. 5 FUSE)





(a) Remove the IGCT No. 5 fuse from the fusible link block.
(b) Measure the resistance.
Standard resistance:
Below 1 Ohms
(c) Reinstall the IGCT No. 5 fuse.
NG -- CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE
OK -- Continue to next step.
2. INSPECT HV CONTROL ECU (BATT VOLTAGE)





(a) Measure the voltage between the terminals of the H29 and H31 HV control ECU connectors.
Standard voltage:






NG -- CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - IGCT NO. 5 FUSE, IGCT NO. 5 FUSE - BATTERY)
OK -- REPLACE HV CONTROL ECU
3. CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - IGCT NO. 5 FUSE, IGCT NO. 5 FUSE - BATTERY)





(a) Check the harness and the connector between the IGCT No. 5 fuse and HV control ECU.
(1) Remove the IGCT No. 5 fuse from the fusible link block.
(2) Disconnect the H29 HV control ECU connector.
(3) Measure the resistance.
Standard resistance (Check for open):






Standard resistance (Check for short):






(4) Reconnect the HV control ECU connector.
(5) Reinstall the IGCT No. 5 fuse.
(b) Check the harness and the connector between the IGCT No. 5 fuse and battery.
(1) Remove the IGCT No. 5 fuse from the fusible link block.
(2) Disconnect the positive battery terminal.
(3) Measure the resistance.
Standard resistance (Check for open):






Standard resistance (Check for short):






(4) Reconnect the positive battery terminal.
(5) Reinstall the IGCT No. 5 fuse.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. INSPECT BATTERY
(a) Check that the battery is not depleted.
NG -- REPLACE BATTERY
OK -- CHECK AND REPLACE FUSIBLE LINK BLOCK