Toyota Celica 2005 Repair Manual page 839

DI−640
DTC P2645
CIRCUIT DESCRIPTION
In order to improve the engine performance at both high and low engine speeds, the VVTL−i system varies
valve lift using the standard cam and high lift cam. This provides the high power engine performance as well
as an emission reduction and good fuel economy.
When the engine speed reaches 6,000 rpm, the ECM sends signals the OCV for VVTL−i to switch the effec-
tive cam from standard one to high lift one hydraulically.
The ECM controls the OCV to apply hydraulic pressure to the piston in the rocker arm and switches the rocker
arm by locking the slipper for high speed.
DTC No.
P2645 Open or short in oil control valve for VVTL circuit
MONITOR DESCRIPTION
When the engine RPM is high, the VVTL−i actuator advances shims under the high−lift cam followers using
engine oil pressure. Switching to the high−lift cam increases the valve lift as well as the intake air volume
and exhaust capacity. These changes increase the engine's power output.
When the engine RPM is 6,000 rpm or more, the ECM increases the OCV control signal duty−ratio and it
opens the oil passage to the VVTL−i actuator. The engine oil pressure powered actuator advances the cam
follower shims and valves begin using the high−lift cam.
The ECM senses the current flow to the OCV to determine the "actual" duty−ratio of the control signal. If the
duty−ratio is out of the normal range, the ECM interprets this as a malfunction in the OCV. The ECM will illumi-
nate the MIL and a DTC will be set.
MONITOR STRATEGY
Related DTCs
Required sensors/components
Frequency of operation
Duration
MIL operation
Sequence of operation
TYPICAL ENABLING CONDITIONS
Item
The monitor will run whenever this DTC is
not present
Battery Voltage
Starter
2005 CELICA (RM1131U)
DIAGNOSTICS
OCV for VVTL Circuit (Bank 1)
DTC Detecting Condition
OCV for VVTL−i
Continuous
1 sec.
Immediate
None
Minimum
− ENGINE (2ZZ−GE)
S Open or short in OCV circuit
S OCV for VVTL−i
S Oil pressure switch for VVTL−i
S ECM
P2645
Specification
See page DI−295
11 V
OFF
838
Trouble Area
OCV for VVTL−i circuit is open/shorted
Maximum
−
DIC7X−02