P0012
1ZZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0011: Camshaft Position "A" - Timing Over-Advanced or System Performance (Bank 1)
DTC P0011 - Camshaft Position "A" - Timing Over-Advanced or System Performance (Bank 1)
DTC P0012 - Camshaft Position "A" - Timing Over-Retarded (Bank 1)
DESCRIPTION
HINT: If DTC P0011 or P0012 is present, check the VVT (Variable Valve Timing) system.
The Variable Valve Timing (VVT) system includes the ECM, OCV and VVT controller. The ECM sends a target duty-cycle control signal to the OCV. This control signal regulates the oil pressure supplied to the VVT controller. Camshaft timing control is performed according to engine operating conditions such as the intake air volume, throttle valve position and engine coolant temperature.
The ECM controls the OCV, based on the signals transmitted by several sensors. The VVT controller regulates the intake camshaft angle using oil pressure through the OCV. As a result, the relative positions of the camshaft and crankshaft are optimized, the engine torque and fuel economy improve, and the exhaust emissions decrease under overall driving conditions. The ECM detects the actual intake valve timing using signals from the camshaft and crankshaft position sensors, and performs feedback control. This is how the target intake valve timing is verified by the ECM.
MONITOR DESCRIPTION
The ECM optimizes the intake valve timing using the VVT (Variable Valve Timing) system to control the intake camshaft. The VVT system includes the ECM, the Oil Control Valve (OCV) and the VVT controller. The ECM sends a target duty-cycle control signal to the OCV. This control signal regulates the oil pressure supplied to the VVT controller. The VVT controller can advance or retard the intake camshaft.
If the difference between the target and actual intake valve timings is large, and changes in actual intake valve timing are small, the ECM interprets this as the VVT controller stuck malfunction and sets a DTC.
Example:
A DTC is set when the following conditions 1), 2) and 3) are met:
1) The difference between the target and actual intake valve timings is more than 5°CA (Crankshaft Angle) and the condition continues for more than 4.5 seconds.
2) It takes 5 seconds or more to change the valve timing by 5°CA.
3) After above conditions 1) and 2) are met, the OCV is forcibly activated 63 times or more.
DTC P0011 (Advanced Cam Timing) is subject to 1 trip detection logic.
DTC P0012 (Retarded Cam Timing) is subject to 2 trip detection logic.
These DTCs indicate that the VVT controller cannot operate properly due to OCV malfunctions or the presence of foreign objects in the OCV.
The monitor will not run unless the following conditions are met:
- The engine is warm (the engine coolant temperature is 75°C [167°F] or more).
- The vehicle has been driven at more than 40 mph (64 km/h) for 3 minutes.
- The engine has idled for 3 minutes.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P0011:
P0012:
If the difference between the target and actual camshaft timings is greater than the specified value, the ECM operates the VVT (Variable Valve Timing) actuator.
Then, the ECM monitors the camshaft timing change for 5 seconds.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTE: DTC P0011 or P0012 may be set when foreign objects in the engine oil are caught in some parts of the system. The DTC will remain set even if the system returns to normal after a short time. Foreign objects are filtered out by the oil filter.
HINT: Read freeze frame data using Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0011 OR P0012)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(d) Read DTCs.
Result:
HINT: If any DTCs other than P0011 or P0012 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART
A -- Continue to next step.
2. PERFORM ACTIVE TEST BY TECHSTREAM (OPERATE OCV)
(a) Connect Techstream to the DLC3.
(b) Start the engine and turn the tester on.
(c) Warm up the engine.
(d) On the tester, select the following menu items: Powertrain / Engine and ECT / Active Test / Control the VVTL System (Bank1).
(e) Check the engine speed while operating the Oil Control Valve (OCV) using the tester.
OK:
NG -- CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN)
OK -- Continue to next step.
3. CHECK WHETHER DTC OUTPUT RECURS (DTC P0011 OR P0012)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Clear DTCs (DTC Check / Clear).
(d) Start the engine and warm it up.
(e) Switch the ECM from normal mode to check mode using the tester (Check Mode Procedure).
(f) Drive the vehicle for more than 10 minutes.
(g) Read DTCs using the tester.
OK:
No DTC output.
OK -- END
NG -- Continue to next step.
4. CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN)
(a) Remove the cylinder head cover (Removal).
(b) Turn the crankshaft pulley, then align its groove with the timing mark "0" on the timing chain cover.
(c) Check that the point marks on the camshaft timing gears are aligned with the timing chain cover surface as shown in the illustration.
If not, turn the crankshaft 1 revolution (360°), then align the marks as above.
OK:
Point marks on camshaft timing gears are aligned with timing chain cover surface.
(d) Reinstall the cylinder head cover (Installation).
NG -- ADJUST VALVE TIMING
OK -- Continue to next step.
5. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (OCV)
(a) Remove the OCV.
(b) Measure the resistance between the terminals of the OCV.
Standard resistance:
6.9 to 7.9 Ohms at 20°C (68°F)
(c) Apply the positive battery voltage to terminal 1 and negative battery voltage to terminal 2. Check the valve operation.
OK:
Valve moves quickly.
(d) Reinstall the OCV.
NG -- REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY
OK -- Continue to next step.
6. INSPECT OIL CONTROL VALVE FILTER
(a) Remove the generator (Removal).
(b) Remove the OCV filter (Disassembly).
(c) Check that the filter is not clogged.
OK:
Filter is not clogged.
(d) Reinstall the OCV filter (Reassembly).
(e) Reinstall the generator (Installation).
NG -- CLEAN OIL CONTROL VALVE FILTER
OK -- Continue to next step.
7. REPLACE CAMSHAFT TIMING GEAR ASSEMBLY
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Clear DTCs (DTC Check / Clear).
(d) Start the engine and warm it up.
(e) Switch the ECM from normal mode to check mode using the tester (Check Mode Procedure).
(f) Drive the vehicle for more than 10 minutes.
(g) Confirm that no DTC is set using the tester.
OK:
No DTC output.
HINT: DTC P0011 or P0012 is output when foreign objects in engine oil are caught in some parts of the system. These codes will stay registered even if the system returns to normal after a short time. These foreign objects are than captured by the oil filter, thus eliminating the source of the problem.
NG -- REPLACE ECM
OK -- END