Rick's Free Auto Repair Advice

P0016, P0018 Toyota

P0016, P0018 Toyota

Diagnose and fix P0016, P0018 Toyota

P0016, P0018 Toyota trouble codes are defined as:


On engines with variable valve timing the ECM commands the variable valve timing (VVT) system to advance or retard camshaft timing. The system accomplishes this by duty cycling an oil control valve (OCV) that pulses oil pressure to the VVT controller.

The ECM sets the intake camshaft to the most retarded angle while the engine is idling by closing the OCV to retard the cam. The ECM examines the data from the crankshaft position sensor and stores this value as the VVT learning value.

Next, the ECM monitors the CKP values while driving and when it sees a difference between the target and actual intake valve timings is 5 degrees CA (Crankshaft Angle) or less, the ECM stores it.

The system sets a P0016 or P0018 trouble code if the ECM sees a CKP signal that is either less than 27 degrees CA, or more than 49 degrees CA for 18 seconds or more. These trouble codes indicate that the intake camshaft has been installed toward the crankshaft at an incorrect angle, caused by factors such as the timing chain having jumped a tooth.

This monitor begins to run after the engine has idled for 5 minutes.

Causes of P0016, P0018 Toyota

Sludge buildup in OCV due to neglected oil changes.

Worn or inoperative OCV

Stretched timing chain, due to neglected oil changes

Diagnose root cause of P0016, P0018 Toyota

1. Clear the trouble codes

2. Start the engine and let it idle for 20-30 minutes without touching the pedal. If the codes return, the problem is likely NOT the OCV or the VVT mechanism. If it does reset either code, remove the OCV and check for sludge deposits, electrical contact issues or improper OCV operation.

3. If you rule out the OCV, check for timing chain stretch or a jumped tooth.

4. Remove valve cover

5. Turn crankshaft pulley and align the crank groove with the o° timing mark on the timing chain cover.

P0016 Toyota

This diagram is for a 4.0L engine. Refer to the diagram for your particular engine.

Check the timing marks on the camshaft timing gears to ensure they’re aligned with the marks on the bearing caps. If not, rotate the engine a full 360° and check again.
P0016 toyota

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Posted on by Rick Muscoplat


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