AutoCodes – Infiniti – P1820 Infiniti

P1820 Infiniti Code - Engine Speed Signal

Quick Answer

The Engine Control Module (ECM) transmits the engine speed signal via CAN communication to the transfer control unit. Common causes include Faulty Engine Control Module (ECM), Faulty Transfer Control Unit, Engine Control Module (ECM) harness is open or shorted. 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: P1820 Infiniti indicates Engine Speed Signal.
Common causes: Common causes include Faulty Engine Control Module (ECM), Faulty Transfer Control Unit, Engine Control Module (ECM) harness is open or shorted.
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 3,936

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 21, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1820 Infiniti Description

The Engine Control Module (ECM) transmits the engine speed signal via CAN communication to the transfer control unit. DTC P1820 will set when either of the following occur:
- Malfunction is detected in engine speed signal that is output from the ECM.
- Improper signal is input while driving.

OBDII Code P1820 Infiniti - Engine Speed Signal - AutoCodes.com — P1820 Infiniti Code - Engine Speed Signal

What does this mean?

What are the Possible Causes of the DTC P1820 Infiniti?

Faulty Engine Control Module (ECM)
Faulty Transfer Control Unit
Engine Control Module (ECM) harness is open or shorted
Engine Control Module (ECM) circuit poor electrical connection

How to Fix the DTC P1820 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 P1820 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 P1820 Infiniti code?

Need more information on how to fix the P1820 Infiniti code? Get Access to Factory Service Manuals

Need Help with the 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.

Frequently Asked Questions about P1820 Infiniti Code

1. What does the OBDII code P1820 mean on an Infiniti?

P1820 indicates an issue with the engine speed signal, which is critical for proper transmission and engine operation.

2. What are the common symptoms of a P1820 code on an Infiniti?

Symptoms may include erratic shifting, reduced engine performance, the transmission stuck in one gear, or the check engine light turning on.

3. What causes the P1820 code on an Infiniti?

Common causes include a faulty engine speed sensor, damaged wiring or connectors, or a malfunctioning transmission control module (TCM).

4. Can I still drive my Infiniti with the P1820 code?

Driving with a P1820 code may result in poor performance and potential damage to the transmission, so itâ€™s best to address the issue promptly.

5. How is the P1820 code diagnosed?

A mechanic will use a scan tool to confirm the code, inspect the engine speed sensor and related wiring, and perform tests on the TCM if necessary.

6. How do you fix the P1820 code on an Infiniti?

Repairs may include replacing the engine speed sensor, repairing damaged wiring, or reprogramming or replacing the TCM.

7. How much does it cost to repair the P1820 code on an Infiniti?

The repair cost varies depending on the issue, but sensor replacement typically ranges from $150 to $300, including labor.

8. What tools are needed to troubleshoot a P1820 code?

A diagnostic scan tool, multimeter, and possibly an oscilloscope are needed to properly diagnose and troubleshoot this code.

9. Can a dirty or contaminated transmission fluid cause the P1820 code?

While uncommon, dirty or contaminated transmission fluid can sometimes lead to sensor issues or poor signal transmission, contributing to the code.

10. Is the P1820 code specific to Infiniti vehicles?

No, P1820 is a generic OBDII code, but the exact meaning and repair procedures can vary depending on the make and model. For Infiniti, it relates to the engine speed signal.