P0012
2ZR-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 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 timings 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
Advanced camshaft timing:
Retarded camshaft timing:
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
NOTICE: 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 a 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 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 a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester 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 FOR INTAKE CAMSHAFT)
(a) Connect a Techstream to the DLC3.
(b) Start the engine.
(c) Turn the tester ON.
(d) Turn the air conditioning switch to ON.
(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 OCV (for intake camshaft) using the tester.
OK:
HINT: If the result is not acceptable, cool the engine and perform the Active Test again.
(g) Start the engine when the engine coolant temperature is 30 °C (86 °F) or less.
(h) Turn the tester ON.
(i) Turn the air conditioning switch to ON.
(j) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1).
(k) Check the engine speed while operating the OCV (for intake camshaft) using the tester with the engine coolant temperature is 50 °C (122 °F) or less.
OK:
NG -- INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (FOR INTAKE CAMSHAFT)
OK -- Continue to next step.
3. CHECK WHETHER DTC OUTPUT RECURS (DTC P0011 OR P0012)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester 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 tester Check Mode Procedure.
(g) Drive the vehicle for more than 10 minutes.
(h) Read DTCs.
Result:
B -- ADJUST VALVE TIMING
A -- CHECK FOR INTERMITTENT PROBLEMS
4. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (FOR INTAKE CAMSHAFT)
(a) Remove the OCV (for intake camshaft) 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 OCV (for intake camshaft) Installation.
NG -- REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (FOR INTAKE CAMSHAFT)
OK -- Continue to next step.
5. INSPECT CAMSHAFT TIMING GEAR ASSEMBLY (FOR INTAKE CAMSHAFT)
(a) Inspect the camshaft timing gear assembly (for intake camshaft) Engine Unit.
NG -- REPLACE CAMSHAFT TIMING GEAR ASSEMBLY (FOR INTAKE CAMSHAFT)
OK -- Continue to next step.
6. INSPECT OIL CONTROL VALVE FILTER
(a) Remove the OCV filter Disassembly.
(b) Check that the filter is not clogged.
OK:
Filter is not clogged.
(c) Reinstall the OCV filter Reassembly.
NG -- CLEAN OIL CONTROL VALVE FILTER
OK -- Continue to next step.
7. ADJUST VALVE TIMING
HINT: There are no marks on the cylinder head to match-up for the purpose of checking valve timing. Valve timing can only be inspected by lining up the colored plates on the timing chain with the marks on the pulleys. It may be necessary to remove and re-install the chain to match up the alignment marks Reassembly.
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS (DTC P0011 OR P0012)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester 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 tester.
(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 part 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