AutoCodes – Infiniti – P0078 Infiniti

P0078 Infiniti Code - Exhaust Valve Timing Control Magnet Retarder Circuit Bank 1

Quick Answer

Exhaust valve timing control magnet retarder controls the shut/open timing of the exhaust valve by ON/OFF pulse duty signals sent from the Engine Control Module (ECM). Common causes include Faulty Exhaust Valve Timing Control Magnet Retarder, Exhaust Valve Timing Control Magnet Retarder harness is open or shorted, Exhaust Valve Timing Control Magnet Retarder circuit poor electrical circuit connector. 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: P0078 Infiniti indicates Exhaust Valve Timing Control Magnet Retarder Circuit Bank 1.
Common causes: Common causes include Faulty Exhaust Valve Timing Control Magnet Retarder, Exhaust Valve Timing Control Magnet Retarder harness is open or shorted, Exhaust Valve Timing Control Magnet Retarder circuit poor electrical circuit connector.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 15,767

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 Oct 25, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0078 Infiniti Description

Exhaust valve timing control magnet retarder controls the shut/open timing of the exhaust valve by ON/OFF pulse duty signals sent from the Engine Control Module (ECM). The longer pulse width retards valve angle. The shorter pulse width advances valve angle.

OBDII Code P0078 Infiniti - Exhaust Valve Timing Control Magnet Retarder Circuit Bank 1 - AutoCodes.com — P0078 Infiniti Code - Exhaust Valve Timing Control Magnet Retarder Circuit Bank 1

What does this mean?

What are the Possible Causes of the DTC P0078 Infiniti?

Faulty Exhaust Valve Timing Control Magnet Retarder
Exhaust Valve Timing Control Magnet Retarder harness is open or shorted
Exhaust Valve Timing Control Magnet Retarder circuit poor electrical circuit connector

How to Fix the DTC P0078 Infiniti?

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 P0078 Infiniti 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 P0078 Infiniti code?

Need more information on how to fix the P0078 Infiniti code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0078 Infiniti code diagnosed by a professional: Find a repair shop in your area

Information for Specific Infiniti Models

P0078 2005 Infiniti G35 — Exhaust Valve Timing Control Magnet Retarder Circuit Bank 1
P0078 2006 Infiniti G35 — Exhaust Valve Timing Control Magnet Retarder Circuit Bank 1

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.