P0012
2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: DTC P0012 - Camshaft Position "A" - Timing Over-Retarded (Bank 1)
DESCRIPTION
The VVT (variable valve timing) system adjusts the intake valve timing to improve the driveability. The engine oil pressure turns the VVT controller to adjust the valve timing. The Camshaft Timing Oil Control Valve (OCV) is a solenoid valve and switches the engine oil line. The valve moves when the ECM applies the 12 V to the solenoid. The ECM changes the energizing time to the solenoid (duty-cycle) in accordance with the camshaft position, crankshaft position, throttle position, etc.
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 Camshaft Timing Oil Control Valve (OCV) and the VVT controller (camshaft timing gear assembly). 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 the 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 and 2 are met for 10 seconds or more:
1. The difference between the target and actual intake valve timing is more than 5°CA (Crankshaft Angle) and the condition continues for more than 5 seconds.
2. It takes 5 seconds or more to change the valve timing by 5°CA.
- 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 run if all of 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 64 km/h (40 mph) for 3 minutes.
- The engine has idled for 3 minutes.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
- If the difference between the target and actual camshaft timings is greater than the specified value, the ECM operates the VVT actuator.
- Then, the ECM monitors the camshaft timing change for 5 seconds.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
- 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.
- Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0011 OR P0012)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream ON.
(d) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(e) 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 USING TECHSTREAM (OPERATE OCV)
(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream ON.
(d) Warm up the engine.
(e) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1).
(f) Check the engine speed while operating the Camshaft Timing Oil Control Valve (OCV) using the Techstream.
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 the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream ON.
(d) Clear DTCs DTC Check / Clear.
(e) Start the engine and warm it up.
(f) Switch the ECM from normal mode to check mode using the Techstream Check Mode Procedure.
(g) Drive the vehicle for more than 10 minutes.
(h) Read DTCs.
Result
B -- CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN)
A -- CHECK FOR INTERMITTENT PROBLEMS
4. CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN)
(a) Remove the cylinder head cover Adjustments.
(b) Turn the crankshaft pulley, and align its groove with the alignment mark "0" of the timing chain cover.
(c) Check that the alignment marks of the camshaft timing gears are aligned with the alignment marks of the bearing cap as shown in the illustration.
If not, turn the crankshaft 1 revolution (360°), then align the marks as above.
OK:
Alignment marks on camshaft timing gears are aligned as shown in the illustration.
(d) Reinstall the cylinder head cover Adjustments.
NG -- ADJUST VALVE TIMING
OK -- Continue to next step.
5. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY
(a) Remove the camshaft timing oil control valve assembly Removal.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(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 camshaft timing oil control valve assembly Installation.
NG -- REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY
OK -- Continue to next step.
6. INSPECT OIL CONTROL VALVE FILTER
(a) Remove the oil control valve filter Disassembly.
OK:
Filter is not clogged.
(b) Remove the oil control valve filter Reassembly.
NG -- CLEAN OIL CONTROL VALVE FILTER
OK -- Continue to next step.
7. REPLACE CAMSHAFT TIMING GEAR ASSEMBLY
(a) Replace the camshaft timing gear assembly Removal.
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream ON.
(d) Clear DTCs DTC Check / Clear.
(e) Start the engine and warm it up.
(f) Switch the ECM from normal mode to check mode using the Techstream Check Mode Procedure.
(g) Drive the vehicle for more than 10 minutes.
(h) Read DTCs.
Result
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 output for a short time even after the system returns to normal. These foreign objects are then captured by the oil filter, thus eliminating the source of the problem.
B -- REPLACE ECM
A -- END