The CVVT (Continuously
Variable Valve Timing) system is installed to the chain sprocket of the
intake camshaft. This system controls the intake camshaft to provide the
optimal valve timing. The PCM controls the Oil Control Valve(OCV), based
on the signals output from mass air flow, throttle position and engine
coolant temperature. The CVVT controller regulates the intake camshaft
angle using oil pressure through the OCV. As result, the relative position
between the camshaft and the crankshaft becomes optimal, and the engine
torque improves, fuel economy improves, exhaust emissions decrease under
overall driving conditions.
PCM detects CAM phasing
average rate while cam signal is normally generating.
PCM determines that a
fault exists and a DTC is stored while vehicle is tip - in and out driving
for 5 minutes.
Item
|
Detecting
Condition
|
Possible cause
|
DTC
Strategy
|
| •
|
Determines if the phaser is moving at an
expected rate | |
| •
|
Excessive phasing system
leakage |
| •
|
Binding Oil Pressure
(ex. Blockage in OCV
filter) |
|
EnableConditions
|
| •
|
CAM signal is normally
generating |
| •
|
Perform tip-in and out more than 10 time
for 5 min. while
driving | |
Threshold
value
|
| •
|
Cam phasing is abnormally fast or
slow | |
Diagnosis
Time
|
| •
|
Continuous (Within
5min.) | |
MIL On
Condition
|
|
This example shows a
typical Crankshaft Position Sensor (CKPS) and Camshaft Position Sensor
(CMPS) waveform at idle. If the 17th signal of the CKPS after missing
tooth is aligned with the high signal of the CMPS at idle, PCM recognizes
that Synchronization between CKPS and CMPS is completed.
| 1. |
Check DTC Status
| (1) |
Connect scantool to Data Link
Connector(DLC). |
| (3) |
Select "DTC" button, and then Press "DTC
Status" to check DTC's information from the DTCs
menu. |
| (4) |
Read "DTC Status"
parameter.
|
| (5) |
Is parameter displayed "Present
fault"?
|
|
▶ Go
to "System Inspection" procedure.
|
|
|
▶
Fault is intermittent caused by PCM memory was not
cleared after repair. Erase DTC and drive the vehicle to
satisfy the enable condition then, go to "System
Inspection"
procedure.
|
| |
■ Visual Inspection
| 1. |
Check oil level is
O.K. |
| 2. |
Check Oil and OCV is
contaminated. |
| 3. |
Check that any oil leakage is occurred around
OCV. |
| 4. |
Has a problem been found?
|
|
▶ Repair or
replace as necessary and then, go to "Verification of Vehicle
Repair" procedure.
|
|
|
▶ Go to
"Component Inspection"
procedure.
|
|
■ Check OCV resistance
| 1. |
IG "OFF" and disconnect OCV
connector. |
| 2. |
Measure resistance between power and signal
terminals of OCV. (Component Side)
Specification
: 6.7 ~ 7.7 Ω
| |
| 3. |
Is the measured resistance within
specification ?
|
|
▶ Go to
"Check CAM PHASER with actuation test" as
follows.
|
|
|
▶
Substitute with a known - good OCV and check for proper
operation.
If the problem is
corrected, replace OCV and go to "Verification of Vehicle
Repair"
procedure.
|
|
■ Check Cam Phaser With Actuation Test
| 1. |
Connect scantool and IG
"ON" |
| 2. |
Select "CAM PHASER INTAKE BANK 1" on the
Actuation Test. |
| 3. |
Select "OIL CONTROL VALVE" on the Actuation
Test. |
| 4. |
Activates "CAM PHASER INTAKE BANK 1" by
pressing "STRT(F1)" key. |
| 5. |
Activates "OIL CONTROL VALVE" by pressing
"STRT(F1)" key. |
| 6. |
Repeat this procedure 4 or 5 times to ensure
CAM PHASER and intake valve control solenoid
reliability.
|
| 7. |
Has a problem been found ?
|
|
▶
Substitute with a known - good CVVT or OCV and check for
proper operation.
If the problem is
corrected, replace CVVT or OCV and go to "Verification of
Vehicle Repair" procedure.
|
|
|
▶ Fault is
intermittent. Drive the vehicle to meet the enable condition
for the DTC. and Go to "Verification of Vehicle Repair"
procedure.
|
|
| Verification Of Vehicle
Repair |
After a repair, it is
essential to verify that the fault has been corrected.
| 1. |
Connect scantool and select "DTC"
button. |
| 2. |
Press "DTC Status" button and confirm that
"DTC Readiness Flag" indicates "Completed". If not, drive the
vehicle within conditions noted in the freeze frame data or enable
conditions |
| 3. |
Read "DTC Status"
parameter |
| 4. |
Is parameter displayed "History(Not Present)
fault"?
|
|
▶ System
performing to specification at this time. Clear the
DTC
|
|
|
▶ Go to the
applicable troubleshooting
procedure.
|
|
