The CVVT (Continuously Variable Valve Timing) system built on the camshaft helps the engine decrease the exhaust gas and increase engine power and fuel economy by changing the valve open/close timing of the intake camshaft continuously. The intake valve control solenoid, the main control part of the CVVT, changes the direction of the oil path through the CVVT by the duty control of the PCM and changes the open and close timing of the intake and exhaust valves.
PCM sets DTC P0077 if the PCM detects that the OCV control circuit is open or short to battery
Item
Detecting Condition
Possible Cause
DTC Strategy
? Electrical check
? Open or short to battery in control circuit
? Contact resistance in connectors
? Faulty Intake Valve Control Solenoid
Enable Conditions
? 100mS after ignition key ON
? 10 < Battery voltage < 16
Threshold Value
? Open or short to battery
Diagnostic Time
? 2 seconds
Intake valve control solenoid
Normal Parameter
Insulation Resistance (?)
above 50 ?
Temp.(?)
Resistance(?)
0
32
6.2 ~ 7.4
60
140
8.0 ~ 9.2
10
50
6.5 ~ 7.7
70
150
8.3 ~ 9.5
20
68
6.8 ~ 8.0
80
176
8.6 ~ 9.8
30
86
7.1 ~ 8.3
90
194
8.9 ~ 10.1
40
104
7.4 ~ 8.6
100
212
9.2 ~ 10.4
122
7.7 ~ 8.9