DTC P1794:00 [SKYACTIV-D 2.2]

DESCRIPTION	Capacitor (i-ELOOP) system: Capacitor (i-ELOOP) malfunction
DETECTION CONDITION	Determination conditions	Capacitor malfunction determined • Any one of the following conditions is met: ― Capacitor (i-ELOOP) internal resistance exceeds the specification. ― Capacitor (i-ELOOP) capacitance exceeds the specification. ― Capacitor (i-ELOOP) voltage exceeds the specification. Capacitor deterioration determined • Any one of the following conditions is met: ― Capacitor (i-ELOOP) internal resistance exceeds the specification. ― Capacitor (i-ELOOP) capacitance is less the than specification. Over-charge determined • Capacitor (i-ELOOP) voltage exceeds the specification.
	Preconditions	• Not applicable.
	Drive cycle	• 1
	Self test type	• CMDTC self test
	Sensor used	• PCM
FAIL-SAFE FUNCTION	• Illuminates the i-stop warning light (amber) • The following vehicle conditions differ depending on the type of malfunction ― Master warning light is illuminated (illumination during bypass mode by i-ELOOP) ― Charging system warning light is illuminated (illumination while generator output is inhibited) ― The pre-charge mode is implemented after the engine is started.
VEHICLE STATUS WHEN DTCs ARE OUTPUT	• Illuminates the i-stop warning light (amber) • Master warning light is illuminated (illumination during bypass mode by i-ELOOP) • Charging system warning light is illuminated (illumination while generator output is inhibited)
POSSIBLE CAUSE	• Engagement malfunction in capacitor (i-ELOOP), DC-DC converter (i-ELOOP) • Blown capacitor fuse • Capacitor (i-ELOOP) malfunction ― Capacitor related wiring harnesses malfunction ― Capacitor (i-ELOOP) malfunction • Generator overcharge (in this case, PCM detects DTC P2504:00) • DC-DC converter (i-ELOOP) malfunction • PCM malfunction

• The capacitor can store generated electrical energy from the generator efficiently. The electrical energy stored during deceleration fuel-cut is used during driving and while the engine is stopped by i-stop, which reduces the power generating load on the generator and the amount of fuel consumption.

• If a malfunction occurs with the capacitor, constant charging takes place by operation of the bypass mode which could cause the fuel economy to worsen. In this diagnostic, the internal resistance/capacitance is calculated from the capacitor voltage value and charge/discharge current value, and the PCM determines that there is a malfunction in the battery-related parts by the internal resistance/capacitance/capacitor voltage exceeding the specified value, and it stores a DTC.

1. If the negative battery cable is disconnected and re-connected, perform the battery condition initial setting (i-stop setting) to complete the i-stop initial setting.

2. Start the engine.

3. Turn off all electrical loads.

Note

• i-ELOOP control can switch to the mode for charging the capacitor by implementing the fuel injection amount learning.

4. Perform the “FUEL INJECTOR INJECTION AMOUNT CORRECTION”. (See FUEL INJECTOR INJECTION AMOUNT CORRECTION [SKYACTIV-D 2.2])

2. Switch the ignition on and wait for 1 min.

3. Switch the ignition off and wait for 20 min.

4. Switch the ignition on.

Item	Definition	Unit	Condition/Specification
CHRGLP	Charging system warning light	OFF/ON	• Charging system warning light illuminates: On • Charging system warning light not illuminates: Off
CAP_SYS_10	Capacitor (i-ELOOP) management system fail-New data object 10	OFF/ON	• Open circuit status in capacitor (i-ELOOP) is not normal: On • Open circuit status in capacitor (i-ELOOP) is normal: Off
CAP_SYS 13	Capacitor (i-ELOOP) management system fail-New data object 13	OFF/ON	• Capacitor (i-ELOOP) capacitance status is not normal: On • Capacitor (i-ELOOP) capacitance status is normal: Off
CAP_SYS 14	Capacitor (i-ELOOP) management system fail-New data object 14	OFF/ON	• Capacitor (i-ELOOP) capacitance status deteriorates: On • Capacitor (i-ELOOP) capacitance status is normal: Off
CAP_SYS 15	Capacitor (i-ELOOP) management system fail-New data object 15	OFF/ON	• Internal resistance status in capacitor (i-ELOOP) is not normal: On • Internal resistance status in capacitor (i-ELOOP) is normal: Off
CAP_SYS 16	Capacitor (i-ELOOP) management system fail-New data object 16	OFF/ON	• Internal resistance status in capacitor (i-ELOOP) deteriorates: On • Internal resistance status in capacitor (i-ELOOP) is normal: Off

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.
1		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. (See DTC INSPECTION [i-ELOOP].) • Are any DTCs present?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [i-ELOOP].) • Repair the malfunctioning location and go to the troubleshooting procedure to perform the procedure from Step 5.
2		No	Go to the next step.
3	PURPOSE: VERIFY IF DIAGNOSTIC RESULT IS AFFECTED BY DTC RELATED TO GENERATOR OVERCHARGE OR WIRING HARNESS BETWEEN GENERATOR AND CAPACITOR • Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 2.2].) • Has DTC P2502, P2503, or P2504:00 been recorded?	Yes	Go to the applicable PENDING CODE or DTC inspection. (See DTC P2502:00 [SKYACTIV-D 2.2] .) (See DTC P2503:00 [SKYACTIV-D 2.2].) (See DTC P2504:00 [SKYACTIV-D 2.2].) Repair the malfunctioning location and go to the troubleshooting procedure to perform the procedure from Step 5.
3		No	Go to the next step.
4	PURPOSE: Determine if the malfunction is caused by capacitor by verifying the PID related to the capacitor. • Access the following PIDs using the M-MDS (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 2.2].) ― CAP_SYS_10 ― CAP_SYS 13 ― CAP_SYS 14 ― CAP_SYS 15 ― CAP_SYS 16 • Are all of the displayed PID values turned off or is the CAP_SYS_10 display on?	Yes	Note • A capacitor malfunction due to over-voltage is possible even if all the PIDs displayed in Step 4 indicate “Off”. • Because an open circuit in the capacitor can be considered if the CAP_SYS_10 display is on, perform diagnosis from Step 1 of the malfunction diagnostic procedure. Finish the function inspection using the M-MDS and perform diagnosis from Step 1 of the malfunction diagnostic procedure.
4		No	Go to the next step.
5	PURPOSE: Determine if the malfunction is caused by capacitor by verifying the PID related to the capacitor. • Of the PID values displayed in Step 3, is On indicated for the CAP_SYS 13 display?	Yes	Note • Because a malfunction related to the capacitor capacitance can be considered if the CAP_SYS_13 display is on, replace the capacitor. Replace the capacitor (i-ELOOP). (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) Go to the troubleshooting procedure to perform the procedure from Step 5.
5		No	Go to the troubleshooting procedure to perform the procedure from Step 4.

STEP	INSPECTION	RESULTS	ACTION
1	PURPOSE: VERIFY IF MALFUNCTION DUE TO BLOWN CAPACITOR FUSE • Switch the ignition to off. • Remove the service plug. (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP]) • Remove the capacitor fuse. (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) • Is the capacitor fuse blown?	Yes	Note • Because the procedure was performed while the service plug was installed, the capacitor fuse may have blown. Replace the capacitor fuse, then go to Step 3. (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].)
1		No	Go to the next step.
2	PURPOSE: VERIFY IF MALFUNCTION IS CAUSED BY POOR TIGHTENING OF BOLTS INSTALLED TO CAPACITOR • Verify the bolt tightening condition. (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) • Is the bolt tightening condition normal?	Yes	Replace the capacitor, then go to the next step. (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].)
2		No	Tighten the bolts correctly, then go to the next step.
3	PURPOSE: VERIFICATION OF VEHICLE REPAIR COMPLETION • Make sure to reconnect all disconnected connectors. • Reinstall the service plug. (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].) • Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC [SKYACTIV-D 2.2].) • Perform the following procedure: 1. Start the engine. 2. Wait for 3 min while idling. 3. Stop the engine. • Perform the DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 2.2].) • Is the same DTC present?	Yes	If capacitor is not replaced: • Replace the capacitor, then perform the malfunction diagnostic procedure in Step 3. (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) If capacitor is replaced: • Perform diagnostic from Step 1 of the “Function inspection using M-MDS”. ― If the malfunction recurs, replace the PCM, then go to Step 7. (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
3		No	Go to Step 6.
4	PURPOSE: VERIFY IF MALFUNCTION CAUSED BY ENGAGEMENT MALFUNCTION OF EACH PART • Switch the ignition to off. • Remove the service plug. (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP]) • Verify that the following parts are engaged correctly. ― DC-DC converter (i-ELOOP) (See DC-DC CONVERTER (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) ― Capacitor (i-ELOOP) (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) • Is the engagement condition of each part normal?	Yes	Go to the next step.
4		No	Tighten the DC-DC converter (i-ELOOP) or capacitor (i-ELOOP) properly, then go to the next step.
5	PURPOSE: VERIFICATION OF VEHICLE REPAIR COMPLETION • Make sure to reconnect all disconnected connectors. • Reinstall the service plug. (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].) • Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC [SKYACTIV-D 2.2].) • Implement the repeatability verification procedure No.1. (See Repeatability Verification Procedure No.1.) • Perform the DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 2.2].) • Is the same DTC present?	Yes	If capacitor is not replaced: • Replace the capacitor, then perform the malfunction diagnostic procedure in Step 5. (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) If capacitor is replaced: • Perform diagnostic from Step 1 of the “Function inspection using M-MDS”. ― If the malfunction recurs, replace the PCM, then go to Step 7. (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
5		No	Go to the next step.
6	PURPOSE: VERIFICATION OF VEHICLE REPAIR COMPLETION • Implement the repeatability verification procedure No.2. (See Repeatability Verification Procedure No.2.) • Perform the DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 2.2].) • Is the same DTC present?	Yes	If capacitor is not replaced: • Replace the capacitor, then perform the malfunction diagnostic procedure in Step 5. (See CAPACITOR (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) If capacitor is replaced: • Perform diagnostic from Step 1 of the “Function inspection using M-MDS”. ― If the malfunction recurs, replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
6		No	Go to the next step.
7	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].)
7		No	DTC troubleshooting completed.