Engine-Codes - Buick - P0018 BUICK

P0018 BUICK - Crankshaft Position - Camshaft Position Correlation Bank 2 Sensor 'A'

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

P0018 BUICK Possible Causes

  • Mechanical timing fault
  • Blocked oil passage
  • Low oil level
  • Faulty Intake ('A') Camshaft Position (CMP) Sensor
  • Faulty Crankshaft Position (CKP) Sensor

How is the P0018 BUICK code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Tech Notes

If this Diagnostic Trouble Code (DTC) started after recent internal engine repairs, inspect for proper engine mechanical timing. With the camshaft cover removed and the #1 cylinder at top dead center, make sure that the darkened chain links are lined up with the alignment marks on the exhaust and intake cam sprockets.

There is a factory service bulletin for the following Buick models:
2007 Buick Allure
2007-2012 Buick LaCrosse
2008-2012 Buick Enclave
Buick Factory Service Bulletin OBDII Code P0018

What is the cost to diagnose the P0018 BUICK code

Labor: 1.0

The cost to diagnose the P0018 BUICK code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

When is the code detected?

The Powertrain Control Module (PCM) has detected the actual Camshaft Position (CMP) Sensor angle of one camshaft is greater or less than the commanded state.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Engine hard to start
  • Engine stall while driving

P0018 BUICK Meaning

The Crankshaft Position (CKP) sensor is a permanent magnet generator, known as a variable reluctance sensor. The magnetic field of the sensor is altered by a crankshaft mounted reluctor wheel that has seven machined slots, 6 of which are equally spaced 60 degrees apart. The seventh slot is spaced 10 degrees after one of the 60 degree slots. The CKP sensor produces seven pulses for each revolution of the crankshaft. The pulse from the 10 degree slot is known as the sync pulse. The sync pulse is used to synchronize the coil firing sequence with the crankshaft position. The CKP sensor is connected to the Powertrain Control Module (PCM) by a signal circuit and a low reference circuit.
The Camshaft Position (CMP) sensor is triggered by a notched reluctor wheel built into the exhaust camshaft sprocket. The CMP sensor provides 6 signal pulses every camshaft revolution. Each notch, or feature of the reluctor wheel is of a different size for individual cylinder identification. This means the CMP and crankshaft position (CKP) signals are pulse width encoded to enable the PCM to constantly monitor their relationship. This relationship is used to determine camshaft actuator position and control its phasing at the correct value. The PCM also uses this signal to identify the compression stroke of each cylinder, and for sequential fuel injection. The CMP sensor is connected to the PCM by a 12-volt, low reference, and signal circuit.

More Information

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