Understanding P0016 and P0018 Codes on a Toyota

Troubleshooting P0016 and P0018 Codes on a Toyota

The P0016 and P0018 codes on a Toyota are very common and not difficult to fix. These codes relate to the engine’s timing system and can indicate serious issues if not addressed promptly. This article will delve into the causes, symptoms, and solutions for these codes.

What Are P0016 and P0018 Codes?

DTCs P0016 and P0018 are both related to the engine’s timing system. They specifically refer to the correlation between the camshaft and crankshaft positions.
P0016: Camshaft Position (CMP) Correlation Error with Crankshaft Position (CKP) Sensor Bank 1 Sensor A.
P0018: Crankshaft Position (CKP) Correlation Error with Camshaft Position Sensor Bank 2 Sensor A.

These codes indicate that the Engine Control Module (ECM) has detected a misalignment between the camshaft and crankshaft positions, which is critical for the engine’s proper operation.

How Toyotas Variable Valve Timing Works

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.

The Most Common Causes of P0016 and P0018 codes on a Toyota

• Sludge buildup in OCV due to neglected oil changes.
• Worn or inoperative OCV
• A Stretched timing chain due to neglected oil changes

VVT solenoid oil control valve

Diagnose the root cause of P0016 and P0018 codes on a 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.

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.

©, 2019 Rick Muscoplat