M20F-FXS, M20G-FXS ENGINE CONTROL SFI SYSTEM P056014 System Voltage Circuit Short to Ground or Open
MONITOR DESCRIPTION
The auxiliary battery supplies electricity to the ECM 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 auxiliary battery voltage falls below a minimum level, the memory is cleared and the ECM determines that there is a malfunction in the power supply circuit. The ECM will illuminate the MIL and store this DTC.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Note |
|---|---|---|---|---|---|
| P056014 | System Voltage Circuit Short to Ground or Open | An open or short in the ECM backup power source circuit (1 trip detection logic). | ·
Open or short in back up power source circuit ·
Auxiliary battery ·
Auxiliary battery terminals ·
ECM |
Comes on | SAE Code: P0562 |
MONITOR STRATEGY
| Required Sensors/Components | ECM |
| Frequency of Operation | Continuous |
TYPICAL MALFUNCTION THRESHOLDS
| Continuous auxiliary battery voltage | Less than 3.5 V |
CONFIRMATION DRIVING PATTERN
- HINT:
- ·
After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
·When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the GTS on.
Wait 5 seconds or more [A].
Enter the following menus: Powertrain / Engine / Trouble Codes [B].
Read the pending DTCs.
- HINT:
- ·
If a pending DTC is output, the system is malfunctioning.
·If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P056014.
Check the DTC judgment result.
| GTS Display | Description |
|---|---|
| NORMAL | ·
DTC judgment completed ·
System normal |
| ABNORMAL | ·
DTC judgment completed ·
System abnormal |
| INCOMPLETE | ·
DTC judgment not completed ·
Perform driving pattern after confirming DTC enabling conditions |
- HINT:
- ·
If the judgment result is NORMAL, the system is normal.
·If the judgment result is ABNORMAL, the system is malfunctioning.
·[A] to [B]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
·When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
- NOTICE:
- ·
Inspect the fuses for circuits related to this system before performing the following procedure.
·After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.
·Vehicle Control History may be stored in the hybrid vehicle control ECU assembly if the engine is malfunctioning. Certain vehicle condition information is recorded when Vehicle Control History is stored. Reading the vehicle conditions recorded in both the Freeze Frame Data and Vehicle Control History can be useful for troubleshooting.
(Select Powertrain in Health Check and then check the time stamp data.)
·If any "Engine Malfunction" Vehicle Control History item has been stored in the hybrid vehicle control ECU assembly, make sure to clear it. However, as all Vehicle Control History items are cleared simultaneously, if any Vehicle Control History items other than "Engine Malfunction" are stored, make sure to perform any troubleshooting for them before clearing Vehicle Control History.
- HINT:
-
Read Freeze Frame Data using the GTS. The ECM 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 moving or stationary, 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
- OK:
Auxiliary battery voltage is between 11 to 14 V.
- Result:
Proceed to OK NG
OK
NG
Check that the auxiliary battery terminals are not loose or corroded.
- OK:
Auxiliary battery terminals are not loose or corroded.
- Result:
Proceed to OK NG
OK
NG
| *a | Front view of wire harness connector
(to ECM) |
Disconnect the ECM connector.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition A47-1 (BATT) - Body ground Always 11 to 16 V
- Result:
Proceed to OK NG
OK
NG
Clear the DTCs.
- Powertrain > Engine > Clear DTCs
- 50002 372
Turn the ignition switch off and wait for at least 30 seconds.
- Result:
Proceed to NEXT
NEXT
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Read the DTCs.
- Powertrain > Engine > Trouble Codes
- 50001 372
- Result:
Result Proceed to DTCs are not output A DTC P056014 is output B
A
B