Tip & How-To about Ford F

Understanding Variable Camshaft Timing (VCT)

Variable Camshaft Timing
With all of the gadgets on cars today, most of us find enough to boggle our minds inside of the passenger compartment let alone what's under the hood. Recently, many manufacturers have moved torward VCT's to improve performance, emissions and to eliminate other components. Let's start with the EGR valve or exhaust gas recirculation system. By installing a variable camshaft system on the exhaust camshaft, the manufacturers were able to eliminate the EGR valve, save money, and lower emissions.

VCT's have been installed on exhaust cams, intake cams, both cams and single overhead cams. The system is operated by using engine oil pressure to move a phaser that is mounted to the end of the camshaft and adjusts the camshaft timing while the engine is running. This is a brilliant system and the performance gained is amazing. The oil that is pressurized by the oil pump moves through oil channels to a solenoid that is controlled by the vehicles computer. The computer takes input signals from various sensors, processes the information and sends a signal to the solenoid that operates the cam phaser and in turn, adjusts the camshaft as needed.

How can I keep my variable camshaft system in good working order?
The best way to keep your VCT system is good condition is to perform regular oil changes and use a factory approved oil filter. Use of an aftermarket filter that is not factory approved can damage your engine. The material that makes up the internal portion of the filter must meet strict guidelines to assure that the material doesn't break away and enter the engines oil channels. This could block the oils path to the camshaft phaser and cause conditions such as rough running, noise and poor emissions/fuel economy. Dirty oil is a VCT's worse enemy. A few dollars extra can save thousands in repairs.

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what does the code p0012 mean


Hi Craig, hope your doing well today. The code you have P0012 means: Camshaft Timing Over-Retarded. It could be the Camshaft Position Actuator on Bank 1 or Computer and even Wiring Related. Without checking it out there is no way of knowing which is the problem. Unless you have a lot of money and just want to try the actuator, I suggest you have it checked out. Hope this helps and have an awesome day Craig!

Jun 03, 2014 | Ford Taurus Cars & Trucks

1 Answer

ford bf fault code p1388


Hi there:DTC P1388 - Variable Cam Timing Overretarded (Bank #2)
Over-******** timing is detected. The PCM detected that the Variable Cam Timing "VCT" position indicated that the camshaft timing was over-******** when compared to a calibrated limit
Possible causes are::- Camshaft timing improperly set. - No oil flow to piston chamber. - VCT (variable cam timing) solenoid stuck open. - Camshaft advance mechanism binding (VCT unit).
Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.
Thank you for using FixYa, have a nice day.

Jun 21, 2012 | Cars & Trucks

1 Answer

where is vct solenoid


Hi there:A code P0012 refers to the VVT (Variable Valve Timing) or VCT (Variable Camshaft Timing) components and the car's PCM (Powertrain Control Module, also called an ECM).
That consists of a few different components but the P0012 DTC specifically refers to the camshaft (cam) timing. In this case, if the cam timing is over-********, the engine light will be illluminated and the code will be set. The "A" camshaft is either the intake, left, or front camshaft.


A P0012 DTC trouble code may be caused by one or more of the following:

- Incorrect camshaft timing

- Wiring problems (harness/wiring) in intake timing control valve control solenoid system

- Continuous oil flow to VCT piston chamber

- Failed timing valve control solenoid (stuck open)



On Ford, the VCT solenoid is located at top of cylinder head underneath the valve cover and goes around one camshaft. You will need to remove the valve cover, the timing cover, then remove the timing belt, the camshaft sprockets, and finally the camshafts to remove the vct solenoid as it goes around the camshaft. You can use 2001-2003 models with same engine.



VCT or Variable Cam Timing solenoid is a device used in modern engines to change camshaft position timing in relevance to engine speed and engine timing allowing the engine to produce more horsepower without adding excessive overlap to the camshaft design.


The way the VCT Solenoid works is as follows:
The VCT solenoid works with oil pressure, it receives a signal from the ECM when the camshaft needs to be rotated either in the advanced mode or ******** mode depending on engine load and speed.The VCT solenoid is able to accomplish that by altering the oil flow in the passages that lead to the cam phaser(s), there are passages to advance the valve timing ( open the valves earlier), and passages that direct the oil to ****** the valve timing ( open them later)

The purpose of the VCT or Variable Cam Timing system is to allow the engine to move larger volumes of air in and out of the cylinders to generate maximum horsepower.
Vehicles with DOHC ( Dual Overhead Cam ) engines usually have two VCT solenoids mounted in each cylinder head, one for each camshaft, allowing the Engine Control Computer to activate each VCT timing mechanism in each Camshaft separately.
NOTE: The Cam phaser is mounted on the front of the camshaft(s) it is driven by the engine's timing chain or timing belt depending on the engine's design.



Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Jun 20, 2012 | Cars & Trucks

1 Answer

have a code p0010 on my 06 ford fusion. where do i find it for bank 1. or what is causing it


P0010 - Intake Camshaft Position Actuator Circuit Open Bank 1

Possible Causes:
- Variable Camshaft Timing (VCT) position circuit is open or shorted
- Variable Camshaft Timing (VCT) position circuit poor electrical connection
- Faulty Variable Camshaft Timing (VCT) position solenoid

Jan 03, 2011 | Ford Fusion Cars & Trucks

1 Answer

i need to know how to set thte timing chain


Discoverd this indepth expalaination of process steps involved in the installation of the timing chain from an ASE certified technician. I hope this helps. See the repair manual on the link below.<br /> <br /> Link: <a href="http://www.2carpros.com/forum/2002-jaguar-xj8--gearbox-default-appear-on-dashboard/2000-jaguar-xj8-timing-chain-replacement-vt218070.html">http://www.2carpros.com/forum/2002-jaguar-xj8--gearbox-default-appear-on-dashboard/2000-jaguar-xj8-timing-chain-replacement-vt218070.html</a><br /> <table id="table14" style="BORDER-RIGHT: #000000 1px dashed; BORDER-TOP: #000000 1px dashed; BORDER-LEFT: #000000 1px dashed; BORDER-BOTTOM: #000000 1px dashed" bordercolordark="#000000" width="100%" bordercolorlight="#000000" border="0"> <tbody> <tr> <td style="BORDER-TOP-WIDTH: 1px" width="700"></td></tr> <tr> <td style="BORDER-TOP-WIDTH: 1px" width="700"><span class="name" roundtrip="0" lastvisited="3">By <a name="755408"></a><b roundtrip="0" lastvisited="0">Dave H</b>,<b> </b></span><span class="postdetails" roundtrip="0" lastvisited="0">Certified ASE Technician</span></td></tr> <tr> <td style="BORDER-TOP-WIDTH: 1px" width="100%" roundtrip="0" lastvisited="6"></td></tr> <tr> <td style="BORDER-TOP-WIDTH: 1px" width="700"></td></tr> <tr> <td style="BORDER-LEFT-WIDTH: 1px; BORDER-BOTTOM-WIDTH: 1px; BORDER-RIGHT-WIDTH: 1px"> </td> </tr> <tr> <td colspan="2"> <span class="postbody" roundtrip="0" lastvisited="77">PRIMARY TIMING CHAINS (NON-SUPERCHARGED) <br />NOTE:The 4.0L V8 has no engine timing alignment marks on the crankshaft or camshafts. Engine timing is achieved by installing the Crankshaft Setting Peg (303-531) and Camshaft Locking Tool (303-530). With the crankshaft setting peg in position, ensure the timing flat on each camshaft is in the uppermost position before installing camshaft locking tool. Variable camshaft timing unit may also be referred to as Variable Valve Timing (VVT) unit. <br /><br />NOTE:Special Tools Required: Crankshaft Setting Peg (303-531), Camshaft Locking Tool (303-530), Chain Tensioning Tool (303-532), Primary Chain Wedge (303-533) and Variable Camshaft Timing Oil Control Unit Setting Tool (303-654). See Fig. 232-Fig. 236 . <br /><br />NOTE:"A" bank refers to the right/passenger side of the vehicle and "B" bank refers to left/driver side of the vehicle. <br /><br />NOTE:Each door glass automatically drops 12 mm when the door is opened or when the convertible top is raised or lowered. It is important that windows are lowered before battery is disconnected to allow doors to shut properly. <br /><br />Removal ("A" Bank) <br />Tips Click a link to view tip <br />Tech1Tip: special tool <br /><br /><br />Remove timing cover. See TIMING CHAIN COVER (NON-SUPERCHARGED). <br />Remove the variable camshaft timing oil control solenoid. </span><br /> <span class="postbody" roundtrip="0" lastvisited="77">Remove the variable camshaft timing oil control unit housing retaining bolts and remove the variable camshaft timing oil control unit housing. </span><br /> <span class="postbody" roundtrip="0" lastvisited="77">Remove and discard the variable camshaft timing oil control unit housing "O" rings. <br />Raise and support vehicle. Remove the bolt which secures the Crankshaft Position (CKP) sensor to the flywheel housing. Remove the CKP sensor and allow it to hang free under the engine. Remove the torque converter bolts access grommet from the flywheel housing. </span><br /> <span class="postbody" roundtrip="0" lastvisited="77">Install the crankshaft damper bolt (old one) to the crankshaft, hand-tight only. Rotate crankshaft until the triangular arrow indent on the flywheel is visible through the access hole. See Fig. 144. Confirm that the timing flat on each camshaft is uppermost position. <br />Position the crankshaft so that the Crankshaft Setting Peg (303-531) engages fully into the timing slot. Install and tighten the bolt to secure the crankshaft setting peg. See Fig. 145. Remove the crankshaft damper bolt from the crankshaft and lower the vehicle. <br />Install the Camshaft Locking Tool (303-530) to the "A" bank camshafts, aligning the shafts slightly as necessary. Loosen the bolt that secures the exhaust camshaft sprocket and the bolt that secures the variable camshaft timing oil control unit. See Fig. 146. Remove camshaft locking tool. <br />Remove the primary chain tensioner bolts, primary chain tensioner and tensioner backing plate. See Fig. 147. <br />Remove the primary timing chain tensioner pivot bolt and remove the primary timing chain tensioner blade. See Fig. 148. <br />Remove the bolt which secures the primary timing chain guide. Noting the position of the primary timing chain guide, remove the primary timing chain guide from the upper retaining pin. See Fig. 149. <br />Remove the primary timing chain from the variable camshaft timing oil control unit and from the crankshaft sprocket. Clean and inspect all components. <br />Installation <br />If "B" bank timing chain was removed, see INSTALLATION. If not, go to next step. <br />If previously removed, install the timing chain sprocket to the crankshaft. The teeth of the "A" bank and the "B" bank timing chain sprockets on the crankshaft must be out of phase with each other. If they are in phase after installing, remove the sprocket, turn it on its vertical axis and reinstall sprocket. See Fig. 150. <br />Install the chain tensioning tool to the exhaust camshaft sprocket. Reposition the sprocket (and the variable camshaft timing oil control unit) for the most advantageous position for use of the tool. See Fig. 151. Remove the tool. <br />Install the primary timing chain into position over the crankshaft sprocket and the variable camshaft timing oil control unit. There must be no slack on the drive side of the primary timing chain and the sprockets must not be rotated on the camshafts, or the tensioning tool may not fit. See Fig. 152. <br />Install the primary timing chain tensioner blade to the cylinder block. See Fig. 148. Install the pivot bolt and tighten specification. See TORQUE SPECIFICATIONS. <br />Push the primary timing chain tensioner piston into the tensioner body to provide clearance for installing the primary timing chain. Insert a thin rigid wire through the hole in the end of the tensioner piston to displace the ball from the non-return valve seat. See Fig. 153. With the wire in position, press the piston fully into the tensioner body. Remove the wire. <br />Install the 2 primary timing chain tensioner bolts to the primary timing chain tensioner and locate the tensioner backing-plate on to the 2 bolts. Align and install the primary timing chain tensioner to the cylinder block and to the mating slot on the rear face of the primary timing chain tensioner blade. See Fig. 147. Tighten the primary timing chain tensioner bolts to specification. See TORQUE SPECIFICATIONS. <br />Use a Primary Chain Wedge (303-533), or 2 if needed, between the primary timing chain tensioner and primary timing chain tensioner blade, to take up the slack in the chain for tightening of the variable camshaft timing control unit and exhaust camshaft sprocket. See Fig. 154. <br />Using the chain tensioning tool, apply force to the tool in an counterclockwise direction to tension the chain on its drive side. See Fig. 151. While applying opposing force to the sprocket and chain, tighten the exhaust camshaft sprocket bolt to specification. See TORQUE SPECIFICATIONS. <br />Using the Variable Camshaft Timing Oil Control Unit Setting Tool (303-654), rotate the variable camshaft timing oil control unit fully counterclockwise to the fully retarded position. See Fig. 155. <br />Check that the primary chain wedges are still in place. While applying opposing force to the sprocket and chain using the chain tensioning tool, tighten the variable camshaft timing oil control unit bolt to specification. See TORQUE SPECIFICATIONS. Remove the chain tensioning tool and the primary chain wedges and camshaft locking tool. <br />Raise and support vehicle. Remove crankshaft setting peg. Install the CKP sensor and bolt to the flywheel housing. See Fig. 143. Tighten the CKP sensor bolt to specification. See TORQUE SPECIFICATIONS. Install the access grommet to the housing and lower the vehicle. <br />WARNING:Check that the ring dowels are engaged squarely. Fully locate the assembly as much as possible by hand. Failure to follow this procedure may result in damage to the vehicle. <br /><br />Install NEW "O" rings to the variable camshaft timing oil control unit housing. Lubricate the "O" rings and the bushing. Install the variable camshaft timing oil control unit housing. See Fig. 142. Install the variable camshaft timing oil control unit housing bolts. Tighten to specification. See TORQUE SPECIFICATIONS. <br />Install the variable camshaft timing oil control solenoid. See Fig. 141. Install and tighten the variable camshaft timing oil control solenoid bolt to specification. See TORQUE SPECIFICATIONS. <br />Install the timing chain cover. See TIMING CHAIN COVER (NON-SUPERCHARGED). </span><br /></td></tr></tbody></table>

Aug 26, 2010 | 2001 Jaguar XJ8

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