DTC P0A94:00 [SKYACTIV-D 2.2]

id0102s4004400

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 (Without i-ELOOP)

DC-DC converter (i-ELOOP): control circuit signal error (With i-ELOOP)
DETECTION CONDITION
Determination conditions
Without i-ELOOP
•  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.
With i-ELOOP
•  Internal malfunction signal from DC-DC converter (i-ELOOP) is received.
•  Condition in which DC-DC converter (i-ELOOP) output voltage, based on demand voltage of PCM, is low continues.
•  When PCM outputs drive command signal for each type of relay in DC-DC converter (i-ELOOP), relay condition signal returned from DC-DC converter (i-ELOOP) differs from drive command, or not returned
•  Condition in which DC-DC converter (i-ELOOP) 2A terminal current value of 30 A or more continues
Preconditions
•  Not applicable
Drive cycle
•  1
Self test type
•  CMDTC self test
Sensor used
•  Not applicable
FAIL-SAFE FUNCTION
•  Inhibits engine-stop by operating the i-stop function.
•  The following fail-safe differ depending on the type of malfunction (with i-ELOOP)
―  Transition to i-ELOOP bypass mode.
―  i-ELOOP bypass mode inhibited.
VEHICLE STATUS WHEN DTCs ARE OUTPUT
•  Flashes i-stop warning light (amber).
•  The following vehicle conditions differ depending on the type of malfunction
―  Illuminates the master warning light
―  Illuminates the charging system warning light
―  The pre-charge mode is implemented after the engine is started. (with i-ELOOP)
POSSIBLE CAUSE
Without i-ELOOP
•  Connector or terminal malfunction of the following parts:
―  PCM
―  Battery
―  DC-DC converter
•  Short to ground in wiring harness between the following terminals:
―  DC-DC converter terminal L—GLOW 80 A fuse
―  GLOW 80 A fuse and/or DCDC DE 40 A fuse malfunction
―  Battery positive terminal—GLOW 80 A fuse
•  Open circuit in wiring harness between the following terminals:
―  DC-DC converter terminal L—GLOW 80 A fuse
―  GLOW 80 A fuse and/or DCDC DE 40 A fuse malfunction
―  Battery positive terminal—GLOW 80 A fuse
•  Battery malfunction
•  DC-DC converter malfunction
•  Front body control module (FBCM) malfunction
•  PCM malfunction
With i-ELOOP
•  Connector or terminal malfunction of the following parts:
―  PCM
―  Battery
―  DC-DC converter (i-ELOOP)
•  Short to ground in wiring harness between the following terminals:
―  DC-DC converter (i-ELOOP) terminal 1F—PCM 2P
―  DC-DC converter (i-ELOOP) terminal 1G—PCM 2A
―  DC-DC converter (i-ELOOP) terminal 1I—PCM 2B
•  Open circuit in wiring harness between the following terminals:
―  DC-DC converter (i-ELOOP) terminal 1F—PCM 2P
―  DC-DC converter (i-ELOOP) terminal 1G—PCM 2A
―  DC-DC converter (i-ELOOP) terminal 1I—PCM 2B
•  High-power load, non-genuine part installed to line connected to DC-DC converter (i-ELOOP) terminal 2A
•  DC-DC converter (i-ELOOP) malfunction
•  PCM malfunction


System Wiring Diagram


Without i-ELOOP

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With i-ELOOP

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Function Explanation (DTC Detection Outline)

Without i-ELOOP
•  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.
With i-ELOOP
•  With the DC-DC converter (i-ELOOP) function, the PCM performs malfunction determination, and verification of vehicle malfunctions/safety assurance is performed.
―  The DC-DC converter (i-ELOOP) is equipped with a voltage lowering function which supplies power to the 12 V line from the 25 V line. If this function does not operate, it may not be possible to supply power to the vehicle’s electrical devices. In this diagnostic, the system detects whether the DC-DC converter (i-ELOOP) can respond to the command voltage from the PCM, or it detects a malfunction in the voltage lowering circuit based on the on-board diagnostic of the DC-DC converter (i-ELOOP).
―  The DC-DC converter (i-ELOOP) is equipped with a discharge circuit which discharges a certain amount of capacitor voltage when the ignition is switched off. If this function does not operate, the capacitor may deteriorate. In this diagnostic, a discharge circuit malfunction condition is detected in the DC-DC converter (i-ELOOP), and a malfunction is determined by the PCM.
―  The DC-DC converter (i-ELOOP) is equipped with a bypass circuit which supplies voltage generated by the generator to the 12 V line. If this function does not operate, a power supply shortage may occur. In this diagnostic, a bypass circuit malfunction condition is detected in the DC-DC converter (i-ELOOP), and a malfunction is determined by the PCM. In addition, a malfunction is determined by the PCM from a mismatch with the response signal of the DC-DC converter (i-ELOOP) in relation to the bypass relay drive command signal from the PCM.
―  To stabilize the power supply of the vehicle’s electrical devices when the engine is restarted by i-stop, the DC-DC converter (i-ELOOP) is equipped with a function which disconnects the power supply of the instrument cluster from the battery and supplies electricity directly through the DC-DC converter (i-ELOOP). If this function does not operate, the power supplied to the vehicle’s electrical devices when the engine is restarted by i-stop could decrease. In this diagnostic, an i-stop relay circuit malfunction condition is detected in the DC-DC converter (i-ELOOP), and a malfunction is determined by the PCM. In addition, a malfunction is determined by the PCM from a mismatch with the response signal of the DC-DC converter (i-ELOOP) in relation to the bypass relay drive command signal from the PCM.
―  The DC-DC converter (i-ELOOP) monitors the input/output voltage and the output current, and the PCM performs charge/discharge control of the generator based on each of the signals to assure the vehicle’s power supply. If the output current of the DC-DC converter (i-ELOOP) exceeds the assurance value of the internal circuit, or each input/output value indicates an abnormal value, normal supply of electricity may not be possible. In this diagnostic, each input/output terminal of the DC-DC converter (i-ELOOP) is detected as an abnormal value/exceeding assurance value, and a malfunction is determined by the PCM.

Repeatability Verification Procedure

Without i-ELOOP
1.  Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC [SKYACTIV-D 2.2].)
2.  Start the engine.
3.  Stop the engine by operating the i-stop function.
With i-ELOOP
1.  Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC [SKYACTIV-D 2.2].)
2.  Start the engine.
3.  Leave for 30 s while idling with no electrical load.
4.  Leave for 30 s while idling with high electrical load.
5.  Stop the engine by operating the i-stop function.

PID Item/Simulation Item Used In Diagnosis

•  Not applicable

Function Inspection Using M-MDS (Without i-ELOOP)

STEP

INSPECTION

RESULTS

ACTION
1
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.
2
PURPOSE: VERIFY IF BATTERY VOLTAGE IS FALSELY RECOGNIZED BY DTC RELATED CAN OR LIN COMMUNICATION
•  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 2.2].)
(See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)
Go to the next step.
No
Go to the troubleshooting procedure to perform the procedure from Step 1.
3
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.
•  Is the PENDING CODE for this DTC 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 (Without i-ELOOP)

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 2.2].)
(See BATTERY REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
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:
―  Repair or replace the wiring harness for a possible short to ground.
―  Replace the malfunctioning fuse.
•  If the fuse is deteriorated:
―  Replace the malfunctioning fuse.
•  If all fuses are normal:
―  Repair or replace the wiring harness for a possible open circuit.
Go to Step 8.
4
PURPOSE: INSPECT DC-DC CONVERTER SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Verify that the DC-DC converter connector is disconnected.
•  Inspect for continuity between DC-DC converter terminal F (wiring harness-side) and body ground.
•  Is there continuity?
Yes
If the short to ground circuit could be detected in the wiring harness:
•  Repair or replace the wiring harness for a possible short to ground.
If the short to ground circuit could not be detected in the wiring harness:
•  Replace the PCM (short to ground in the PCM internal circuit).
Go to Step 8.
No
Go to the next step.
5
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.
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
Repair or replace the wiring harness for a possible short to power supply, then 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
Repair or replace the wiring harness for a possible open circuit, then 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.
•  Perform the KOER self test.
•  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 2.2 (WITHOUT i-ELOOP)].)
•  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 2.2].)
No
DTC troubleshooting completed.


Function Inspection Using M-MDS (With i-ELOOP)

STEP

INSPECTION

RESULTS

ACTION
1
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.
2
PURPOSE: VERIFY IF POWER SUPPLY IS AFFECTED BY DTC RELATED TO DC-DC CONVERTER (i-ELOOP)
•  Switch the ignition to off, then to ON (engine off or on).
•  Perform the DC-DC converter (i-ELOOP) DTC inspection using the M-MDS.
•  Is the PENDING CODE/DTC U3000:49 also present?
Yes
Go to the applicable PENDING CODE or DTC inspection.
(See DTC U3000:49 [i-ELOOP].)
No
Go to the next step.
3
PURPOSE: VERIFY IF POWER SUPPLY IS AFFECTED BY DTC RELATED TO PCM
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Is the PENDING CODE/DTC P0A12:00 also present?
Yes
Go to the applicable PENDING CODE or DTC inspection.
(See DTC P0A12:00 [SKYACTIV-D 2.2].)
No
Go to the next step.
4
PURPOSE: DETERMINE IF MALFUNCTION CAUSED BY DC-DC CONVERTER (i-ELOOP)
•  Start the engine.
•  Is illuminate the master warning light?
Yes
Go to the troubleshooting procedure to perform the procedure from Step 1.
No
Go to the next step.
5
PURPOSE: DETERMINE IF MALFUNCTION CAUSED BY DC-DC CONVERTER (i-ELOOP)
•  Is the charging system warning light illuminated after the engine is restarted by i-stop, or is there an abnormality in the navigation/audio unit behavior?
Yes
Go to the troubleshooting procedure to perform the procedure from Step 3.
No
Go to the troubleshooting procedure to perform the procedure from Step 5.


Troubleshooting Diagnostic Procedure (With i-ELOOP)

Intention of troubleshooting procedure
•  Step 1—2
―  Verifying malfunction related to DC-DC converter (i-ELOOP) 1G or 1I terminal
•  Step 3—4
―  Verifying malfunction related to DC-DC converter (i-ELOOP) 1F terminal
•  Step 5—6
―  Verifying/replacing malfunctioning part
•  Step 7—8
―  Verify that primary malfunction is resolved and there are no other malfunctions.

STEP

INSPECTION

RESULTS

ACTION
1
PURPOSE: VERIFY IF SHORT TO GROUND IN EACH WIRING HARNESS AFFECTS DIAGNOSTIC RESULTS
•  Switch the ignition to off.
•  Disconnect the service plug.
•  Disconnect the connector of the following parts.
―  PCM
―  DC-DC converter (i-ELOOP)
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
―  PCM terminal 2A
―  PCM terminal 2B
―  DC-DC converter (i-ELOOP) terminal 1G
―  DC-DC converter (i-ELOOP) terminal 1I
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  PCM terminal 2A—DC-DC converter (i-ELOOP) terminal 1G
•  PCM terminal 2B—DC-DC converter (i-ELOOP) terminal 1I
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 7.
No
Go to the next step.
2
PURPOSE: VERIFY IF OPEN CIRCUIT IN EACH WIRING HARNESS AFFECTS DIAGNOSTIC RESULTS
•  Verify that the generator, capacitor (i-ELOOP), and DC-DC converter (i-ELOOP) connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  PCM terminal 2A—DC-DC converter (i-ELOOP) terminal 1G
―  PCM terminal 2B—DC-DC converter (i-ELOOP) terminal 1I
•  Is there continuity?
Yes
Replace the DC-DC converter (i-ELOOP).
(See DC-DC CONVERTER (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].)
Go to Step 7.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  PCM terminal 2A—DC-DC converter (i-ELOOP) terminal 1G
•  PCM terminal 2B—DC-DC converter (i-ELOOP) terminal 1I
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 7.
3
PURPOSE: VERIFY IF SHORT TO GROUND IN EACH WIRING HARNESS AFFECTS DIAGNOSTIC RESULTS
•  Switch the ignition to off.
•  Disconnect the service plug.
•  Disconnect the connector of the following parts.
―  PCM
―  DC-DC converter (i-ELOOP)
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
―  PCM terminal 2P
―  DC-DC converter (i-ELOOP) terminal 1F
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  PCM terminal 2P—DC-DC converter (i-ELOOP) terminal 1F
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 7.
No
Go to the next step.
4
PURPOSE: VERIFY IF OPEN CIRCUIT IN EACH WIRING HARNESS AFFECTS DIAGNOSTIC RESULTS
•  Verify that the generator, capacitor (i-ELOOP), and DC-DC converter (i-ELOOP) connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  PCM terminal 2P—DC-DC converter (i-ELOOP) terminal 1F
•  Is there continuity?
Yes
Replace the DC-DC converter (i-ELOOP).
(See DC-DC CONVERTER (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].)
Go to Step 7.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  PCM terminal 2P—DC-DC converter (i-ELOOP) terminal 1F
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 7.
5
PURPOSE: VERIFY IF MALFUNCTION OCCURRING IS CAUSED BY WIRING HARNESS/CONNECTOR LOSS
•  Have all the wiring harnesses/connectors which can be considered the cause of DTC P0A94:00 been inspected?
Yes
Go to the next step.
No
Inspect all the related wiring harnesses/connectors.
If there is a malfunction
•  Repair or replace the connector and/or terminals, then go to Step 7.
If there is no malfunction
•  Go to the next step.
6
PURPOSE: VERIFY DC-DC converter (i-ELOOP) REPLACEMENT RECORD
•  Is the DC-DC converter (i-ELOOP) being replaced within the troubleshooting diagnostic procedure this time?
Yes
Replace the PCM.
(See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
Go to the next step.
No
Replace the DC-DC converter (i-ELOOP).
(See DC-DC CONVERTER (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].)
Go to the next step.
7
PURPOSE: VERIFICATION OF VEHICLE REPAIR COMPLETION
•  Make sure to reconnect all disconnected connectors.
•  Reconnect the service plug.
•  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
Repeat the inspection from Step 5.
No
Go to the next step.
8
PURPOSE: VERIFY IF THERE IS ANY OTHER MALFUNCTION
•  Is any other DTC or pending code stored?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-D 2.2].)
No
DTC troubleshooting completed.