DTC P0A94:00 [PCM (SKYACTIV-G 2.5T)]

id0102s8004400

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

Without i-ELOOP


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
•  Inhibits engine-stop by operating the i-stop function.
VEHICLE STATUS WHEN DTCs ARE OUTPUT
•  Flashes i-stop warning light (amber).
•  A warning message is displayed in the display.
•  Illuminates charging system warning light.
POSSIBLE CAUSE
•  Front body control module (FBCM) malfunction
•  Battery malfunction
•  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 DCDC1 50 A fuse and DC-DC converter terminal L
?  DCDC1 50 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
•  DC-DC converter malfunction
•  PCM malfunction


System wiring diagram

ac9wzw00005777


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 [PCM (SKYACTIV-G 2.5T)].)
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 [PCM (SKYACTIV-G 2.5T)].)
(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 primary malfunction is resolved and there are no other malfunctions.

Diagnostic Procedure

STEP

INSPECTION

RESULTS

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.)
(See BATTERY REMOVAL/INSTALLATION.)
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 DCDC1 50 A fuse.
•  If the fuse is blown:
?  Refer to the wiring diagram and verify whether or not there is a common connector between DCDC1 50 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 fuse.
•  If the fuse is damaged:
?  Replace the fuse.
•  If the fuse is 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 [WITHOUT i-ELOOP (SKYACTIV-G 2.5T)].)
•  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 [PCM (SKYACTIV-G 2.5T)].)
No
DTC troubleshooting completed.


With i-ELOOP


Details on DTCs

DESCRIPTION

DC-DC converter (i-ELOOP): control circuit signal error
DETECTION CONDITION
Determination conditions
•  The PCM receives a response signal from the DC-DC converter (i-ELOOP) which differs from the relay operation command voltage of the PCM.
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.
•  Depending on the type of malfunction, any of the following controls may be implemented.
?  Transition to i-ELOOP bypass mode.
?  i-ELOOP bypass mode inhibited.
VEHICLE STATUS WHEN DTCs ARE OUTPUT
•  Flashes i-stop warning light (amber).
•  A warning message is displayed in the display.
•  The following vehicle conditions differ depending on the type of malfunction
?  Illuminates the master warning light (without multi-information display)
?  Illuminates the charging system warning light
POSSIBLE CAUSE
•  Connector or terminal malfunction of the following parts:
?  PCM
?  DC-DC converter (i-ELOOP)
•  Short to ground in wiring harness between the following terminals:
?  DC-DC converter (i-ELOOP) terminal 1L—PCM terminal 2P
?  DC-DC converter (i-ELOOP) terminal 1D—PCM terminal 2L
•  Open circuit in wiring harness between the following terminals:
?  DC-DC converter (i-ELOOP) terminal 1L—PCM terminal 2P
?  DC-DC converter (i-ELOOP) terminal 1D—PCM terminal 2L
•  DC-DC converter (i-ELOOP) malfunction
•  PCM malfunction


System wiring diagram

ac9wzw00004517


Function explanation (DTC detection outline)

•  The PCM performs malfunction determination of the relay ON/OFF command function for the DC-DC converter (i-ELOOP) for verification of vehicle malfunction/safety assurance.
?  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 occurs.
?  With this diagnosis, a malfunction is determined by the PCM, in which a bypass circuit of the DC-DC converter (i-ELOOP) from the PCM is on or the response signal of the DC-DC converter (i-ELOOP) related to the off command voltage does not match.
?  To stabilize the power supply of the 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 electrical devices from the battery and supplies electricity directly through the DC-DC converter (i-ELOOP). If this function does not operate, the power supply of the electrical devices is turned off instantaneously due to the effect of cranking when the engine is restarted by i-stop.
?  With this diagnosis, a malfunction is determined by the PCM, in which an i-stop relay circuit of the DC-DC converter (i-ELOOP) from the PCM is on or the i-stop relay circuit operation condition of the DC-DC converter (i-ELOOP) related to the off command voltage does not match.


Repeatability verification procedure

1.  Disconnect the negative battery terminal and wait for 10 s or more. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)
2.  Connect the negative battery terminal, start the engine, and maintain the idle status.


PID item/simulation item used in diagnosis

•  Not applicable


Function inspection using M-MDS

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: 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 troubleshooting procedure to perform the procedure from Step 1.


Troubleshooting diagnostic procedure

Intention of troubleshooting procedure
•  Step 1—2
?  Verifying malfunction related to DC-DC converter (i-ELOOP) terminal 1D
•  Step 3—4
?  Verifying malfunction related to DC-DC converter (i-ELOOP) terminal 1L
•  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 off.
•  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:
?  DC-DC converter (i-ELOOP) terminal 1D
•  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 2L—DC-DC converter (i-ELOOP) terminal 1D
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 DC-DC converter (i-ELOOP) and PCM connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
?  PCM terminal 2L—DC-DC converter (i-ELOOP) terminal 1D
•  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 the following terminals:
•  PCM terminal 2L—DC-DC converter (i-ELOOP) terminal 1D
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
•  Verify that the DC-DC converter (i-ELOOP) and PCM connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
?  DC-DC converter (i-ELOOP) terminal 1L
•  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 1L
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 DC-DC converter (i-ELOOP) and PCM connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
?  PCM terminal 2P—DC-DC converter (i-ELOOP) terminal 1L
•  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 the following terminals:
•  PCM terminal 2P—DC-DC converter (i-ELOOP) terminal 1L
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 any 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-G 2.5T].)
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
•  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
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 [PCM (SKYACTIV-G 2.5T)].)
No
DTC troubleshooting completed.