Timing chain stretched, or timing belt skipped a tooth from wear. Misaligned timing belt or chain, or a damaged belt/chain tensioner. Crankshaft or camshaft tone ring slipped or broken. Faulty crankshaft or camshaft position sensor. Damaged wiring to the crank or cam sensor. Improperly torqued, loose or missing crankshaft balancer bolt (listed by OBD-Codes.com). Camshaft actuator solenoid stuck open, or actuator stuck away from its 0-degree position (listed by OBD-Codes.com). Camshaft variable timing solenoid or variable valve timing actuator failure (listed by RepairPal). Engine oil level too low, or oil that doesn't meet the manufacturer's specification (listed by RepairPal). An engine that was rebuilt or timed incorrectly (listed by OBD-Codes.com).

Repair damaged sensor wiring. Replace a faulty crankshaft or camshaft position sensor. Correct the oil level or change to the specified oil. Replace the camshaft variable timing solenoid or actuator. Repair or replace a slipped or broken tone ring, or correctly torque the crankshaft balancer bolt. Replace the timing chain or belt and tensioner, and reset timing (RepairPal lists timing belt replacement as a common repair).

P0018🔧 Engine timing / cam and crank sensorsStop and fix promptly

P0018: Crankshaft/Camshaft Position Correlation (Bank 2 Sensor A) (Meaning, Causes, Fixes)

Q: What does P0018 mean?

P0018 means the engine computer sees the crankshaft and the Bank 2 'A' camshaft (usually the intake cam) out of time with each other by more than it allows. Causes range from a sensor or wiring fault and low or wrong engine oil affecting variable valve timing, up to a stretched timing chain or a skipped timing belt. The crankshaft position sensor (CKP) and camshaft position sensor (CMP) each read a toothed tone ring, and the engine computer (PCM) uses them to time spark and fuel injection. The timing belt or chain ties the two shafts together, so they should stay precisely in step. OBD-Codes.com explains that when the PCM sees the crank and cam signals out of time by a specific number of degrees, it sets P0018. RepairPal adds that newer engines use variable valve timing to shift the camshaft relative to the crankshaft, so if the camshaft isn't in the proper position relative to the crankshaft, the code sets. P0018 is a generic code that only appears on engines with two cylinder banks (V6, V8 and flat engines). 'Bank 2' is the side of the engine that doesn't contain cylinder 1, and OBD-Codes.com says the 'A' sensor is most likely the intake camshaft side. P0016 is the same check on Bank 1, and P0019 is the Bank 2 'B' (usually exhaust) camshaft. OBD-Codes.com notes P0018 often appears together with P0008, P0009, P0016, P0017 and P0019, and suggests GM owners with several of these codes check for service bulletins. Sources emphasize different likely causes: OBD-Codes.com focuses on the sensors, tone rings, timing belt/chain and crankshaft balancer, while RepairPal's list leads with the variable timing solenoid and actuator and with low or incorrect engine oil. RepairPal's page title also leaves out the bank and sensor letter that OBD-Codes.com gives.

Q: Can I keep driving with P0018?

Stop and fix promptly. Get this diagnosed promptly. RepairPal rates P0018 'Urgent'. Possible causes include a stretched timing chain or a timing belt that has skipped a tooth, and OBD-Codes.com notes the engine may run poorly or crank but not start. If you hear rattling from the engine, or it's running badly, avoid driving it until it's checked.

Reviewed 2026-10-24 · Based on 2 cited source(s)

What P0018 means

The crankshaft position sensor (CKP) and camshaft position sensor (CMP) each read a toothed tone ring, and the engine computer (PCM) uses them to time spark and fuel injection. The timing belt or chain ties the two shafts together, so they should stay precisely in step. OBD-Codes.com explains that when the PCM sees the crank and cam signals out of time by a specific number of degrees, it sets P0018. RepairPal adds that newer engines use variable valve timing to shift the camshaft relative to the crankshaft, so if the camshaft isn't in the proper position relative to the crankshaft, the code sets. P0018 is a generic code that only appears on engines with two cylinder banks (V6, V8 and flat engines). 'Bank 2' is the side of the engine that doesn't contain cylinder 1, and OBD-Codes.com says the 'A' sensor is most likely the intake camshaft side. P0016 is the same check on Bank 1, and P0019 is the Bank 2 'B' (usually exhaust) camshaft. OBD-Codes.com notes P0018 often appears together with P0008, P0009, P0016, P0017 and P0019, and suggests GM owners with several of these codes check for service bulletins. Sources emphasize different likely causes: OBD-Codes.com focuses on the sensors, tone rings, timing belt/chain and crankshaft balancer, while RepairPal's list leads with the variable timing solenoid and actuator and with low or incorrect engine oil. RepairPal's page title also leaves out the bank and sensor letter that OBD-Codes.com gives.

Severity: can I keep driving?

Stop and fix promptly

Get this diagnosed promptly. RepairPal rates P0018 'Urgent'. Possible causes include a stretched timing chain or a timing belt that has skipped a tooth, and OBD-Codes.com notes the engine may run poorly or crank but not start. If you hear rattling from the engine, or it's running badly, avoid driving it until it's checked.

Common symptoms

Check engine light on
Reduced engine performance
Increased fuel consumption (listed by RepairPal)
Engine starts and runs, but poorly
Engine cranks but doesn't start
Rattle near the harmonic balancer, which can indicate a damaged tone ring (listed by OBD-Codes.com)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Timing chain stretched, or timing belt skipped a tooth from wear
Misaligned timing belt or chain, or a damaged belt/chain tensioner
Crankshaft or camshaft tone ring slipped or broken
Faulty crankshaft or camshaft position sensor
Damaged wiring to the crank or cam sensor
Improperly torqued, loose or missing crankshaft balancer bolt (listed by OBD-Codes.com)
Camshaft actuator solenoid stuck open, or actuator stuck away from its 0-degree position (listed by OBD-Codes.com)
Camshaft variable timing solenoid or variable valve timing actuator failure (listed by RepairPal)
Engine oil level too low, or oil that doesn't meet the manufacturer's specification (listed by RepairPal)
An engine that was rebuilt or timed incorrectly (listed by OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Read all stored codes. Related codes such as P0016, P0017, P0008, P0335 or P0345 help show whether the problem is on one bank, one sensor, or the timing drive as a whole.
Check the engine oil level and condition, and that the oil meets your owner's manual specification, since RepairPal lists low or incorrect oil as a common cause.
Visually inspect the Bank 2 cam sensor, the crank sensor, and their wiring and connectors. Repair any broken or frayed wires, clear the code and recheck.
If the vehicle is still under powertrain warranty, OBD-Codes.com recommends letting the dealer handle it.
Listen for rattling from the timing cover or harmonic balancer area, and don't keep driving an engine that's rattling or running badly.

Typical fixes

Repair damaged sensor wiring
Replace a faulty crankshaft or camshaft position sensor
Correct the oil level or change to the specified oil
Replace the camshaft variable timing solenoid or actuator
Repair or replace a slipped or broken tone ring, or correctly torque the crankshaft balancer bolt
Replace the timing chain or belt and tensioner, and reset timing (RepairPal lists timing belt replacement as a common repair)

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

Checking the cam and crank signal patterns needs an oscilloscope (OBD-Codes.com)
Inspecting the tone rings or timing chain/belt means removing the cam gear, harmonic balancer or timing cover
The engine cranks but won't start, or rattles
The code returns after you've corrected the oil and checked the wiring

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

What's the difference between P0016 and P0018?

Both mean the crankshaft and an intake ('A') camshaft signal don't agree. P0016 is Bank 1 (the side with cylinder 1) and P0018 is Bank 2, so P0018 only shows up on V-type or flat engines.

Is P0018 always a timing chain problem?

No. Sources list sensor and wiring faults, low or incorrect oil, and variable valve timing solenoid or actuator failures as causes, as well as a stretched chain or skipped belt. Check the simple things first, but don't ignore it.

Can I keep driving with P0018?

RepairPal rates it 'Urgent'. Because a skipped or stretched timing belt/chain is one possible cause, have it diagnosed promptly, and stop driving if the engine rattles or runs badly.

Sources

Last reviewed 2026-10-24. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.