- Valve timing
- Oil control valve (OCV) for exhaust camshaft
- OCV filter
- Camshaft timing exhaust gear
- ECM
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000000XH8032X |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
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 exhaust valve timing is verified by the ECM.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P0014 P0024 |
Exhaust valve timing is not adjusted in valve timing advance range (2 trip detection logic) |
|
|
P0015 P0025 |
Exhaust valve timing is not adjusted in valve timing retard range (1 trip detection logic) |
|
MONITOR DESCRIPTION
- 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, Oil Control Valve (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. 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 stores a DTC.
Example:
A DTC is stored when the following conditions 1, 2 and 3 are met:
1. The difference between the target and actual exhaust valve timing is more than 5°CA (Crankshaft Angle) and the condition continues for more than 4.5 seconds (Procedure "A").
2. It takes 5 seconds or more to change the valve timing by 5°CA (Procedure "B").
3. After above procedures "A" and "B" are met, the OCV is forcibly activated 63 times or more.
- DTCs P0014 and P0024 (Advanced Cam Timing) are subject to 2 trip detection logic.
-
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.
-
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 64 km/h (40 mph) for 3 minutes.
- The engine has idled for 3 minutes.
MONITOR STRATEGY
|
Related DTCs |
P0014: Advanced camshaft timing (for Bank 1) P0015: Retarded camshaft timing (for Bank 1) P0024: Advanced camshaft timing (for Bank 2) P0025: Retarded camshaft timing (for Bank 2) |
|
Required sensors / components (Main) |
VVT OCV and VVT Actuator |
|
Required sensors / components (Related) |
Crankshaft position sensor, Camshaft position sensor and Engine coolant temperature sensor |
|
Frequency of operation |
Once per driving cycle |
|
Duration |
Within 10 seconds |
|
MIL operation |
Advanced camshaft timing: 2 driving cycles Retarded camshaft timing: Immediate |
|
Sequence of operation |
None |
TYPICAL ENABLING CONDITIONS
|
Monitor runs whenever following DTCs are not present |
P0100 - P0103 (MAF sensor) P0115 - P0118 (ECT sensor) P0125 (insufficient ECT for closed loop) P0335 (CKP sensor) P0351 - P0358 (igniter) |
|
Battery voltage |
11 V or more |
|
Engine RPM |
500 to 4000 rpm |
|
Engine coolant temperature |
75 to 100°C (167 to 212°F) |
TYPICAL MALFUNCTION THRESHOLDS
Advanced Camshaft Timing
|
Valve timing |
No change |
|
Valve timing |
Advanced position |
Retarded Camshaft Timing
|
Valve timing |
No change |
|
Valve timing |
Retarded position |
WIRING DIAGRAM
Refer to DTC P0013
.
INSPECTION PROCEDURE
|
Abnormal Bank |
Advanced Timing Over (Valve Timing Out of Specified Range) |
Retarded Timing Over (Valve Timing Out of Specified Range) |
|---|---|---|
|
Bank 1 |
P0014 |
P0015 |
|
Bank 2 |
P0024 |
P0025 |
- 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 No. 1 cylinder.
- 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 No. 1 cylinder.
-
Read freeze frame data using the 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 P0014, P0015, P0024 OR P0025) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read DTCs.
Result
|
Result |
Proceed to |
|---|---|
|
P0014, P0015, P0024 or P0025 |
A |
|
P0014, P0015, P0024 or P0025 and other DTCs |
B |
HINT:
If any DTCs other than P0014, P0015, P0024 or P0025 are output, troubleshoot those DTCs first.
|
|
2. |
PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE OCV) |
(a) Connect the Techstream to the DLC3.
(b) Turn the Techstream on.
(c) Warm up the engine.
(d) Enter the following menus: Powertrain / Engine / Active Test / Control the VVT Exhaust Linear (Bank1) or Control the VVT Exhaust Linear (Bank2).
(e) Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream.
OK:
|
Tester Operation |
Specified Condition |
|---|---|
|
0% |
Normal engine speed |
|
100% |
Engine idles roughly or stalls |
|
|
3. |
CHECK WHETHER DTC OUTPUT RECURS (DTC P0014, P0015, P0024 OR P0025) |
(a) Connect the Techstream to the DLC3.
(b) Turn the Techstream on.
(c) Clear DTCs
.
(d) Warm up the engine.
(e) Switch the ECM from normal mode to check mode using the Techstream
.
(f) With the engine warmed up, idle it for 1 minute. Then drive the vehicle for 5 minutes.
(g) Read DTCs using the Techstream.
OK:
No DTC output.
|
|
6. |
CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN) |
(a) Remove the cylinder head cover LH and RH.
(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 and camshaft timing exhaust gears are at the positions shown in the illustration.
OK:
Alignment marks on camshaft timing gears are aligned as shown in the illustration.
|
|
7. |
INSPECT CAMSHAFT OIL CONTROL VALVE ASSEMBLY (OCV FOR EXHAUST CAMSHAFT) |
|
(a) Remove the OCV
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1 - 2 |
20°C (68°F) |
6.9 to 7.9 Ω |
(c) Apply positive (+) battery voltage to terminal 1 and negative (-) battery voltage to terminal 2. Check the valve operation.
OK:
Valve moves quickly.
|
|
8. |
INSPECT OIL CONTROL VALVE FILTER |
(a) Remove the oil control valve filter
.
(b) Check that the filter is not clogged.
OK:
Filter is not clogged.
|
|
9. |
REPLACE CAMSHAFT TIMING EXHAUST GEAR |
(a) Replace the camshaft timing exhaust gear
.
|
|
10. |
CHECK WHETHER DTC OUTPUT RECURS |
(a) Connect the Techstream to the DLC3.
(b) Turn the Techstream on.
(c) Clear DTCs
.
(d) Warm up the engine.
(e) Switch the ECM from normal mode to check mode using the Techstream
.
(f) With the engine warmed up, idle it for 1 minute. Then drive the vehicle for 5 minutes.
(g) Read the output DTCs using the Techstream.
OK:
No DTC output.
HINT:
DTC P0014, P0015, P0024 or P0025 is output when foreign objects in the 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 filter, thus eliminating the source of the problem.
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