DTC P0079:00 [SKYACTIV-D 2.2]

id0102s4210400

DTC P0079:00

OCV circuit low input

DETECTION CONDITION

•  If the PCM detects that the OCV voltage at the PCM terminal 1CK is less than the specified value for 5 s with the following condition met, the PCM determines that the OCV circuit voltage is low.

MONITORING CONDITIONS

―  Battery voltage: 8—20 V

―  0.5 s have elapsed after the ignition was switched ON (engine off or on)

Diagnostic support note

•  This is a continuous monitor (CCM).

•  The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.

•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

•  DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

•  Inhibits the two-stage turbo control.

•  Inhibits the EGR control.

•  The fast idle up correction for the idle speed control is inhibited.

•  Inhibits engine-stop by operating the i-stop function.

POSSIBLE CAUSE

•  OCV connector or terminals malfunction

•  Short to ground or open circuit in OCV power supply circuit

―  Short to ground in wiring harness between ENGINE1 15 A fuse and OCV terminal A

―  ENGINE1 15 A fuse malfunction

―  Open circuit in wiring harness between main relay terminal D and OCV terminal A

•  Short to ground in wiring harness between OCV terminal B and PCM terminal 1CK

•  PCM connector or terminals malfunction

•  Open circuit in wiring harness between OCV terminal B and PCM terminal 1CK

•  OCV malfunction

•  PCM malfunction

DTC P0079:00	OCV circuit low input
DETECTION CONDITION	• If the PCM detects that the OCV voltage at the PCM terminal 1CK is less than the specified value for 5 s with the following condition met, the PCM determines that the OCV circuit voltage is low. MONITORING CONDITIONS ― Battery voltage: 8—20 V ― 0.5 s have elapsed after the ignition was switched ON (engine off or on) Diagnostic support note • This is a continuous monitor (CCM). • The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle. • FREEZE FRAME DATA (Mode 2)/Snapshot data is available. • DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	• Inhibits the two-stage turbo control. • Inhibits the EGR control. • The fast idle up correction for the idle speed control is inhibited. • Inhibits engine-stop by operating the i-stop function.
POSSIBLE CAUSE	• OCV connector or terminals malfunction • Short to ground or open circuit in OCV power supply circuit ― Short to ground in wiring harness between ENGINE1 15 A fuse and OCV terminal A ― ENGINE1 15 A fuse malfunction ― Open circuit in wiring harness between main relay terminal D and OCV terminal A • Short to ground in wiring harness between OCV terminal B and PCM terminal 1CK • PCM connector or terminals malfunction • Open circuit in wiring harness between OCV terminal B and PCM terminal 1CK • OCV malfunction • PCM malfunction

Diagnostic Procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.
2	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.
2		No	Go to the next step.
3	INSPECT OCV CONNECTOR CONDITION • Switch the ignition off. • Disconnect the OCV 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 9.
3		No	Go to the next step.
4	INSPECT OCV POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT • Verify that the OCV connector is disconnected. • Switch the ignition ON (engine off). • Measure the voltage at the OCV terminal A (wiring harness-side). • Is the voltage B+?	Yes	Go to the next step.
4		No	Inspect the ENGINE1 15 A fuse. • If the fuse is blown: ― Refer to the wiring diagram and verify whether or not there is a common connector between ENGINE1 15 A fuse and OCV terminal A. 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 main relay terminal D and OCV terminal A. 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 9.
5	INSPECT OCV CONTROL CIRCUIT FOR SHORT TO GROUND • Verify that the OCV connector is disconnected. • Switch the ignition off. • Inspect for continuity between OCV terminal B (wiring harness-side) and body ground. • Is there continuity?	Yes	If the short to ground circuit could be detected in the wiring harness: • Refer to the wiring diagram and verify whether or not there is a common connector between OCV terminal B and PCM terminal 1CK. 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. 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). (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].) Go to Step 9.
5		No	Go to the next step.
6	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 9.
6		No	Go to the next step.
7	INSPECT OCV CONTROL CIRCUIT FOR OPEN CIRCUIT • Verify that the OCV and PCM connectors are disconnected. • Inspect for continuity between OCV terminal B (wiring harness-side) and PCM terminal 1CK (wiring harness-side). • Is there continuity?	Yes	Go to the next step.
7		No	Refer to the wiring diagram and verify whether or not there is a common connector between OCV terminal B and PCM terminal 1CK. 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 9.
8	INSPECT OCV • Inspect the OCV. (See OIL CONTROL VALVE (OCV) INSPECTION [SKYACTIV-D 2.2].) • Is there any malfunction?	Yes	Replace the OCV, then go to the next step. (See OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
8		No	Go to the next step.
9	VERIFY DTC TROUBLESHOOTING COMPLETED • Always reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [SKYACTIV-D 2.2].) • Perform the KOEO or KOER self test. (See KOEO/KOER SELF TEST [SKYACTIV-D 2.2].) • Is the same DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].) Go to the next step.
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [SKYACTIV-D 2.2].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [SKYACTIV-D 2.2].)
10		No	DTC troubleshooting completed.