AutoCodes – Generic – P1348

P1348 Code - Misfire During Start Cylinder 4

Quick Answer

As part of the CARB/OBD regulations, the Engine Control Module (ECM) must determine if a misfire is occurring and also identify the specific cylinder(s) and the severity of the misfire event and whether it is emissions relevant or catalyst damaging. Common causes include Faulty Spark Plug, Faulty Ignition Coil, Intake vacuum leak. 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: P1348 indicates Misfire During Start Cylinder 4.
Common causes: Common causes include Faulty Spark Plug, Faulty Ignition Coil, Intake vacuum leak.
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 19,860

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 May 17, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1348 Description

As part of the CARB/OBD regulations, the Engine Control Module (ECM) must determine if a misfire is occurring and also identify the specific cylinder(s) and the severity of the misfire event and whether it is emissions relevant or catalyst damaging. In order to accomplish these tasks, the control module monitors the crankshaft for acceleration losses during firing segments of each cylinder based on firing order.
The misfire/engine roughness calculation is derived from the differences in the period duration (T) of individual increment gear segments. Each segment period consists of an angular range of 120Â° crank angle that starts 78Â° before Top Dead Center (TDC).
If the expected period duration is greater than the permissible value a misfire fault for the particular cylinder is stored in the fault memory of the ECM. Depending on the level of misfire rate measured the control unit will illuminate the "Service Engine Soon" light, may cutoff fuel to the particular cylinder and may switch lambda operation to open-loop. All misfire faults are weighted to determine if the misfire is emissions relevant or catalyst damaging.

OBDII Code P1348 - Misfire During Start Cylinder 4 - AutoCodes.com — P1348 Code - Misfire During Start Cylinder 4

What does this mean?

What are the Possible Causes of the DTC P1348?

Faulty Spark Plug
Faulty Ignition Coil
Intake vacuum leak
Faulty Camshaft Position Sensor
Ignition Coil harness is open or shorted
Ignition Coil circuit poor electrical connection

How to Fix the DTC P1348?

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 P1348 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.

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Information for Specific Makes

P1348 Audi — Ignition Coil Power Output Stage 1 Open Circuit
P1348 BMW — Misfire During Start Cylinder 4
P1348 Hyundai — #8 Ion Line Open
P1348 Isuzu — Variable Valve Timing System Fault Bank 1
P1348 MINI — Misfire During Start Cylinder 4
P1348 Volkswagen — Ignition Coil Power Output Stage 1 Open Circuit

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.