P0025
4GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0014: Camshaft Position "B" - Timing Over-Advanced or System Performance (Bank 1)
DTC P0014 - Camshaft Position "B" - Timing Over-Advanced or System Performance (Bank 1)
DTC P0015 - Camshaft Position "B" - Timing Over-Retarded (Bank 1)
DTC P0024 - Camshaft Position "B" - Timing Over-Advanced or System Performance (Bank 2)
DTC P0025 - Camshaft Position "B" - Timing Over-Retarded (Bank 2)
DESCRIPTION
HINT:
If DTC P0014, P0015, P0024 or P0025 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 exhaust 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 exhaust 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
1 The ECM optimizes the exhaust valve timing using the VVT (Variable Valve Timing) system to control the exhaust camshaft. The VVT system includes the ECM, the Oil Control Valve (OCV) and the VVT controller.
2 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 exhaust camshaft.
If the difference between the target and actual exhaust valve timing is large, and changes in actual exhaust 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 "A" and "B" are met:
1 It takes 5 seconds or more to change the valve timing by 5°CA (Condition "A").
2 After the above condition is met, the OCV is forcibly activated 10 seconds (Condition "B").
3 DTCs P0014 and P0024 (Advanced Cam Timing) are subject to 2 trip detection logic.
4 DTCs P0015 and P0025 (Retarded Cam Timing) are subject to 1 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.
5 The monitor will not run unless the following conditions are met:
1 The engine is warm (the engine coolant temperature is 75°C [167°F] or more).
2 The vehicle has been driven at more than 40 mph (64 km/h) for 3 minutes.
3 The engine has idled for 3 minutes.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
Advanced camshaft timing:
Retarded camshaft timing:
WIRING DIAGRAM
INSPECTION PROCEDURE
- If DTC P0014 or P0015 is displayed, check the bank 1 VVT system for exhaust camshaft circuit.
- Bank 1 refers to the bank that includes cylinder No. 1.
- If DTC P0024 or P0025 is displayed, check the bank 2 VVT system for exhaust camshaft circuit.
- Bank 2 refers to the bank that does not include cylinder No. 1.
- 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 Freeze Frame Data.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0014, P0015, P0024 OR P0025)
(a) Connect Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the tester on.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(d) Read DTCs.
Result:
HINT:
If any DTCs other than P0014, P0015, P0024 or P0025 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART
A -- Continue to next step.
2. PERFORM ACTIVE TEST USING USING TECHSTREAM (OPERATE OCV)
(a) Connect Techstream to the DLC3.
(b) Start the engine and turn the tester on.
(c) Warm up the engine.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Exhaust Linear (Bank 1) or Control the VVT Exhaust Linear (Bank 2).
(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 P0014, P0015, P0024 OR P0025)
(a) Connect Techstream to the DLC3.
(b) Turn the engine switch on (IG) 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.
NG -- CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN)
OK -- END
4. CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN)
(a) Remove the cylinder head covers RH and LH.
(b) Turn the crankshaft pulley, and align its groove with the timing mark "0" of the timing chain cover.
(c) Check that the timing marks of the camshaft timing gears are aligned with the timing 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:
Timing marks on crankshaft timing gears are aligned as shown in the illustration.
(d) Reinstall the cylinder head covers.
NG -- ADJUST VALVE TIMING
OK -- Continue to next step.
5. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (OCV FOR EXHAUST CAMSHAFT)
(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 AND PIPE
(a) Remove the oil pipe No. 1 or No. 2.
(b) Remove the oil control valve filter.
(c) Check that the filter and pipe are not clogged.
OK:
Filter is not clogged.
NG -- CLEAN OIL CONTROL VALVE FILTER AND PIPE
OK -- Continue to next step.
7. REPLACE CAMSHAFT TIMING GEAR ASSEMBLY (FOR EXHAUST CAMSHAFT)
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS
(a) Clear the DTCs.
(1) Operate Techstream, or disconnect the EFI and ETCS fuses more than 60 sec. to erase the codes.
(b) Start the engine and warm up the engine.
(c) Switch the ECM from normal mode to check mode using Techstream Check Mode Procedure.
(d) Drive the vehicle for more than 10 minutes or more.
(e) Read output DTCs using Techstream.
OK:
No DTC output.
HINT:
DTC P0014, P0015, P0024 or P0025 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 then captured by the oil, thus eliminating the source of the problem.
OK -- SYSTEM IS OK
NG -- REPLACE ECM