Follow us on Twitter and win Autohex II Scan Tool for Kia and Hyundai (worth 945.00 USD)

P0268 Cylinder 3 Injector Circuit High

AutoHex Online Help: Hyundai MATRIX(FC) 2005
COMPONENT LOCATION
GENERAL DESCRIPTION

Injectors spray specific amount of fuel which is determined by ECM into the combustion chamber as transforming liquid fuel into fog state. Power generates through combustion process of injected fuel.

The goal of increasing fuel presssure of common rail diesel engine to 1500bar is to transform liquid fuel into fog state. and foggy fuel can decrease exhaust gas and increase power generation of engine and fuel-efficiency. Oil pressure servotype is applied to control 1500bar with solenoid. Injector solenoid operates by current control as raising solenoid operating voltage to 80V. When injector solenoid releases oil pressure of B chamberamong the high pressure loaded to both chambers of needle valve inside of injector, needle valve is lifted by oil pressure and fuel isinjected. When the same intensity of oil pressure is applied to A and B chamber, needle valve is closed by spring tension and fuel injection is cut.

With not applying mechanical injectors but electronically controlled injectors, pilot injection and post injection, injection time and quantity can be controlled independantly. Thus, electronically controlled injectors improve engine performance.



DTC DESCRIPTION

P0268 is set when injector power supply circuit (HIGH side) current of each cylinder above 28A~36A - the maximum current - is detected for more than 0.3 sec. This code is due to short to ground in injector power supply circuit.

DTC DETECTING CONDITION

Item

Detecting Condition

Possible Cause

DTC Strategy

Current monitoring

Injector circuit

Injector component

Enable Conditions

Engine running

Threshold Value

HIGH side excessive current error : HIGH side current is above the maximum value (28~36A)

Diagnostic Time

300ms

Fail Safe

Fuel Cut

NO

Fuel is cut (engine shut down) when the malfunction of more than two injectors occurs.

EGR Off

NO

Fuel Limit

YES

MIL

YES

TERMINAL AND CONNECTOR INSPECTION

Electrical systems consist of a lot of harness and connectors, poor connection of terminals can cause various problems and damge of component.

Perform checking procedure as follows.

Check damage of harness and terminals : Check terminals for contact resistance, corrosion and deformation.

Check connecting condition of ECM and component connector : Check terminal seperation, damage of locking device and connecting condition between terminal and wiring

note

Disconnect the pin which requires checking at mail connector and insert it to the terminal at female connector for checking connecting condition ( after checking, reconnect the pin at correct position )

Is the problem found?

? Repair the trouble causing part and go to "Verification of Vehicle Repair"

? Go to "Power Circuit Inspection"

POWER CIRCUIT INSPECTION

Check open in power circuit

Ignition "OFF", Turn engine "OFF".

Disconnect injector connector(C324-1,2,3,4) and ECM connector(C333-2)

Check continuity between Injector connector terminal 2 and ECM connector terminal 36(No.1,4 cylinder) or 37(No.2,3 cylinder)

Is the measured resistance within the specification?

? Go to "2. Check short to ground in power circuit (HIGH side)" as follows.

? Repair open spots and go to "Verification of Vehicle Repair"

Check short to ground in power circuit (HIGH side)

Ignition "OFF", Turn engine "OFF".

Disconnect injector connector(C324-1,2,3,4) and ECM connector(C333-2)

Check continuity between injector connector terminal 2 and chasis ground.

Is the measured resistance within the specification?

? Go to "Component Inspection"

? Repair short to ground and go to "Verification of Vehicle Repair"

COMPONENT INSPECTION

Check injector component resistance

Ignition "OFF", Turn engine "OFF".

Disconnect injector connector

Measure the resistance between injector component terminal 1 and 2

Is the measured resistance within the specification?

? Go to "Verification of Vehicle Repair"

? Replace injector and go to "Verification of Vehicle Repair"

Check injector using injector test mode of scantool

Ignition "OFF", Turn engine "OFF".

Connect scantool to Data Link Cable (DLC).

Ignition "ON", Turn engine "ON".

Warm engine up to normal operating temperature.

Select 07. ENGINE TEST FUNCTION on scantool.

Perform 01.COMPRESSTION TEST and 02. IDLE SPEED COMPARISON according to TEST procedure suggested on scantool.

Regard the results of these tests in diagnostic result

Perform 03. INJECT QUANTITY COMPARISON test.

Are RPM and fuel correction quantity at certain cylinder is different from the other's a lot?

? Mount the injector whose correction quantity is very different from another's on another cylinder and if same correction quantity is detect, replace injector and go to "Verification of Vehicle Repair"

? Go to "Verification of Vehicle Repair"

? This test is not absolute standard to check failure of injectors, regard this as a reference value when engine stall occurs.

note

The class of injectors installed in engine should be same ( one out of C1, C2, C3 )

When replacing 1 or 2 injectors, subsititute with new injectors which is in the same class with already installed one. If injector class changes

when replacing all injectors, new injector class should be inputted using scantool.(For more information about injector calss, refer to P1670, P1671 )

VERIFICATION OF VEHICLE REPAIR

After a repair, it is essential to verify that the fault is corrected.

After connecting scantool select "Diagnostic Trouble Codes(DTCs)" mode to and then clear DTC.

Drive the vehicle within DTC Enable conditions in General information.

After selecting "Diagnostic Trouble Codes(DTCs)" mode and check DTC is recorded again.

Are any DTCs recorded ?

? Go to the DTC guide of recorded No. in scantool.

? System operates within specification.

SCHEMATIC DIAGRAM