AutoCodes – Generic – P034B

P034B Code - Crankshaft Position Sensor Crankshaft Direction Incorrect

Quick Answer

The Engine Control Module (ECM) monitors the speed and the direction of rotation of the crankshaft during an autostop event and memorizes the crankshaft angle at which the engine stopped to be able to start the engine quicker. Common causes include Faulty Crankshaft Position Sensor, Crankshaft Position Sensor harness is open or shorted, Crankshaft Position Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P034B indicates Crankshaft Position Sensor Crankshaft Direction Incorrect.
Common causes: Common causes include Faulty Crankshaft Position Sensor, Crankshaft Position Sensor harness is open or shorted, Crankshaft Position Sensor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,283

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 23, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P034B Description

The Engine Control Module (ECM) monitors the speed and the direction of rotation of the crankshaft during an autostop event and memorizes the crankshaft angle at which the engine stopped to be able to start the engine quicker. The Diagnostic Trouble Code (DTC) will be set when the direction of rotation of the crankshaft has changed more than 3 times within 10 s.

OBDII Code P034B - Crankshaft Position Sensor Crankshaft Direction Incorrect - AutoCodes.com — P034B Code - Crankshaft Position Sensor Crankshaft Direction Incorrect

What does this mean?

What are the Possible Causes of the DTC P034B?

Faulty Crankshaft Position Sensor
Crankshaft Position Sensor harness is open or shorted
Crankshaft Position Sensor circuit poor electrical connection

How to Fix the DTC P034B?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P034B code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P034B code?

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Need Help with the Code?

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Information for Specific Makes

P034B Buick — Crankshaft Position Sensor Crankshaft Direction Incorrect
P034B Cadillac — Crankshaft Position Sensor Crankshaft Direction Incorrect
P034B Chevrolet — Crankshaft Position Sensor Crankshaft Direction Incorrect
P034B GMC — Crankshaft Position Sensor Crankshaft Direction Incorrect

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.