DTC P0A94:00 [SKYACTIV-D 1.5]

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Note
•  To determine the malfunctioning part, proceed with the diagnostics from "Function Inspection Using M-MDS".

Details On DTCs

DESCRIPTION

DC-DC converter: control circuit signal error
DETECTION CONDITION
Determination conditions
•  Internal malfunction signal from DC-DC converter via front body control module (FBCM) is received. (CAN/LIN communication).
•  Input signal from the DC-DC converter limits the pressure increase time.
•  Input signal from the DC-DC converter does not implement pressure increase after a pressure increase command to the DC-DC converter.
Preconditions
•  Not applicable
Drive cycle
•  1
Self test type
•  CMDTC self test
Sensor used
•  Not applicable
FAIL-SAFE FUNCTION
•  Not applicable
VEHICLE STATUS WHEN DTCs ARE OUTPUT
•  Flashes i-stop warning light (amber).
POSSIBLE CAUSE
•  DC-DC converter connector or terminals malfunction
•  Short to ground or open circuit in DC-DC converter power supply circuit
―  Short to ground in wiring harness between GLOW 80 A fuse and DC-DC converter terminal L
―  GLOW 80 A fuse and/or DCDC DE 40 A fuse malfunction
―  Open circuit in wiring harness between battery positive terminal and DC-DC converter terminal L
•  PCM connector or terminals malfunction
•  Short to ground in wiring harness between DC-DC converter terminal F and PCM terminal 2P
•  Short to power supply in wiring harness between DC-DC converter terminal F and PCM terminal 2P
•  Open circuit in wiring harness between DC-DC converter terminal F and PCM terminal 2P
•  Battery malfunction
•  DC-DC converter malfunction
•  Front body control module (FBCM) malfunction
•  PCM malfunction


System Wiring Diagram

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Function Explanation (DTC Detection Outline)

•  The DC-DC converter is equipped with a boost function to stabilize the power supply to the vehicle’s electrical devices when the engine is restarted by i-stop. If the DC-DC converter does not operate, the supply voltage to the vehicle’s electrical devices decreases. In this diagnostic, the response condition of the DC-DC converter to the boost demand from the PCM, or the boost by the on-board diagnostic function of the DC-DC converter is not detected, and verification of vehicle malfunctions/safety assurance is performed.

Repeatability Verification Procedure

1.  Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC [SKYACTIV-D 1.5].)
2.  Start the engine.
3.  Stop the engine by operating the i-stop function.

PID Item/Simulation Item Used In Diagnosis

•  Not applicable

Function Inspection Using M-MDS

STEP

INSPECTION

RESULTS

ACTION
1
PURPOSE: RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
Note
•  Recording can be facilitated using the screen capture function of the PC.
•  Record the snapshot data on the repair order.
—
Go to the next step.
2
PURPOSE: VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
PURPOSE: VERIFY IF BATTERY VOLTAGE IS FALSELY RECOGNIZED BY DTC RELATED CAN OR LIN COMMUNICATION
•  Switch the ignition off, then ON (engine off).
•  Perform the PCM and front body control module (FBCM) DTC inspection using the M-MDS.
•  Are DTCs related CAN or LIN communication recorded?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [SKYACTIV-D 1.5].)
(See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)
Go to the next step.
No
Go to the next step.
4
PURPOSE: VERIFY IF THE CURRENT SENSOR IS MISIDENTIFYING MALFUNCTIONS DUE TO A FRONT BODY CONTROL MODULE (FBCM) MALFUNCTION
•  Perform the front body control module (FBCM) DTC inspection using the M-MDS.
•  Are any DTCs present?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)
Go to the troubleshooting procedure to perform the procedure from Step 1.
No
Go to the troubleshooting procedure to perform the procedure from Step 1.


Troubleshooting Diagnostic Procedure

Intention of troubleshooting procedure
•  Step 1
―  Perform a unit inspection of the battery.
•  Step 2—7
―  Verify if a malfunction is occurring due to a malfunction in each signal transmission and the boost demand line.
•  Step 8—9
―  Verify that the primary malfunction is resolved and there are no other malfunctions.

Diagnostic Procedure

STEP

INSPECTION

ACTION
1
PURPOSE: INSPECT BATTERY
•  Switch the ignition off.
•  Inspect the battery.
•  Is there any malfunction?
Yes
Recharge or replace the battery, then go to Step 8.
(See BATTERY RECHARGING [SKYACTIV-D 1.5].)
(See BATTERY REMOVAL/INSTALLATION [SKYACTIV-D 1.5].)
No
Go to the next step.
2
PURPOSE: INSPECT DC-DC CONVERTER CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the DC-DC converter connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 8.
No
Go to the next step.
3
PURPOSE: INSPECT DC-DC CONVERTER POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT
•  Verify that the DC-DC converter connector is disconnected.
•  Measure the voltage at the DC-DC converter terminal L (wiring harness-side).
•  Is the voltage B+?
Yes
Go to the next step.
No
Inspect the GLOW 80 A fuse and DCDC DE 40 A fuse.
•  If the fuse is blown:
―  Refer to the wiring diagram and verify whether or not there is a common connector between GLOW 80 A fuse and DC-DC converter terminal L.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
•  Replace the malfunctioning fuse.
•  If the fuse is damaged:
―  Replace the malfunctioning fuse.
•  If all fuses are normal:
―  Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and DC-DC converter terminal L.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 8.
4
PURPOSE: INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 8.
No
Go to the next step.
5
PURPOSE: INSPECT DC-DC CONVERTER SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Verify that the DC-DC converter and PCM connectors are disconnected.
•  Inspect for continuity between DC-DC converter terminal F (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between DC-DC converter terminal F and PCM terminal 2P.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 8.
No
Go to the next step.
6
PURPOSE: INSPECT DC-DC CONVERTER SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the DC-DC converter and PCM connectors are disconnected.
•  Switch the ignition ON (engine off).
Note
•  Another DTC may be stored by the PCM detecting an open circuit.
•  Measure the voltage at the DC-DC converter terminal F (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between DC-DC converter terminal F and PCM terminal 2P.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 8.
7
PURPOSE: INSPECT DC-DC CONVERTER SIGNAL CIRCUIT FOR OPEN CIRCUIT
•  Verify that the DC-DC converter and PCM connectors are disconnected.
•  Switch the ignition off.
•  Inspect for continuity between DC-DC converter terminal F (wiring harness-side) and PCM terminal 2P (wiring harness-side).
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between DC-DC converter terminal F and PCM terminal 2P.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to the next step.
8
PURPOSE: VERIFY DTC TROUBLESHOOTING COMPLETED
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Implement the repeatability verification procedure.
•  Perform the DTC Reading Procedure.
•  Is the same DTC present?
Yes
Replace the DC-DC converter, and then perform Step 8 again.
(See DC-DC CONVERTER REMOVAL/INSTALLATION [SKYACTIV-D 1.5].)
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
9
PURPOSE: VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-D 1.5].)
No
DTC troubleshooting completed.