AutoCodes – GMC – P1320 GMC

P1320 GMC Code - IC Module 4X Reference Circuit Intermittent No Pulses

Quick Answer

With the engine speed over 568 rpm, the Powertrain Control module (PCM) did not receive any 4X Fuel Control pulses for 400 ms. Common causes include Faulty or worn out spark plugs, Faulty fuel injectors, Faulty Camshaft Position Sensor. 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: P1320 GMC indicates IC Module 4X Reference Circuit Intermittent No Pulses.
Common causes: Common causes include Faulty or worn out spark plugs, Faulty fuel injectors, Faulty Camshaft Position Sensor.
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 4,142

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 Aug 09, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1320 GMC Description

With the engine speed over 568 rpm, the Powertrain Control module (PCM) did not receive any 4X Fuel Control pulses for 400 ms.

OBDII Code P1320 GMC - IC Module 4X Reference Circuit Intermittent No Pulses - AutoCodes.com — P1320 GMC Code - IC Module 4X Reference Circuit Intermittent No Pulses

What does this mean?

What are the Possible Causes of the DTC P1320 GMC?

Faulty or worn out spark plugs
Faulty fuel injectors
Faulty Camshaft Position Sensor
Faulty Crankshaft Position Sensor

How to Fix the DTC P1320 GMC?

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 P1320 GMC 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 P1320 GMC code?

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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.