AutoCodes – Dodge – U1421 Dodge

U1421 Dodge Code - Implausible Ignition Key Off Time Received

Quick Answer

The Body Control Module (BCM) monitors the time the ignition is in the off or accessory position between key cycles and then broadcasts the signal called Ignition Off Time (IOT) via the CANC Bus. Common causes include Faulty Body Control Module (BCM), Body Control Module (BCM) harness is open or shorted, Body Control Module (BCM) 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: U1421 Dodge indicates Implausible Ignition Key Off Time Received.
Common causes: Common causes include Faulty Body Control Module (BCM), Body Control Module (BCM) harness is open or shorted, Body Control Module (BCM) 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 2,447

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 23, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1421 Dodge Description

The Body Control Module (BCM) monitors the time the ignition is in the off or accessory position between key cycles and then broadcasts the signal called Ignition Off Time (IOT) via the CANC Bus. The Powertrain Control Module (PCM) saves the value from a previous key cycle into powerdown flash and if certain When Monitored conditions are met compares to the current value. If the Set Conditions are met, then a fault U1421 is set indicating the timer is stuck. If this fault becomes active the PCM will light the MIL light immediately. If the MIL is set and the fault goes stored the PCM turns off the MIL after 3 consecutive drive cycles. If the difference between two Ignition Off Times (IOT) sent from the BCM to the PCM during two separate diagnostic decisions is less than 3 minutes for 5 consecutive decisions this fault will set.

OBDII Code U1421 Dodge - Implausible Ignition Key Off Time Received - AutoCodes.com — U1421 Dodge Code - Implausible Ignition Key Off Time Received

What does this mean?

What are the Possible Causes of the DTC U1421 Dodge?

Faulty Body Control Module (BCM)
Body Control Module (BCM) harness is open or shorted
Body Control Module (BCM) circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC U1421 Dodge?

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 U1421 Dodge 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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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 U1421 Dodge Code

1. What are the common symptoms of OBDII code U1421 in a Dodge vehicle?

The common symptoms include issues with starting the vehicle, intermittent stalling, and the engine running rough.

2. What does the OBDII code U1421 Dodge mean?

The code U1421 indicates an implausible ignition key off time received by the vehicle's powertrain control module (PCM).

3. What are the possible causes of the U1421 code in a Dodge?

Potential causes include a faulty ignition switch, a wiring issue in the ignition system, a malfunctioning PCM, or a communication error between modules.

4. How can I diagnose the U1421 code in my Dodge?

Diagnosis typically involves using a diagnostic scanner to retrieve the code, checking for other related codes, inspecting the ignition system components, and testing the PCM and communication circuits.

5. Is it safe to drive with the U1421 fault code present in a Dodge vehicle?

It is generally not recommended to drive with the U1421 code present, as it can lead to unpredictable engine behavior and potential safety hazards.

6. Can I reset the U1421 code in my Dodge without fixing the underlying issue?

While you can clear the code with a diagnostic scanner, it is crucial to address the root cause to prevent the code from reappearing and to ensure proper vehicle operation.

7. How much does it typically cost to repair the U1421 code in a Dodge?

The cost of repair can vary depending on the specific cause of the code, but it may involve replacing the ignition switch, repairing wiring issues, or reprogramming the PCM. Costs can range from a few hundred to over a thousand dollars.

8. Can a DIY enthusiast fix the U1421 code issue in a Dodge?

DIY enthusiasts with experience in automotive repair and access to the necessary tools may be able to diagnose and address simpler causes of the U1421 code, such as checking and repairing wiring connections.

9. How urgent is it to address the U1421 fault code in a Dodge?

It is advisable to address the U1421 code promptly to prevent potential drivability issues, further damage to engine components, and ensure the safety and reliability of the vehicle.

10. Will the U1421 code cause my Dodge to fail an emissions test?

The U1421 code alone may not cause a vehicle to fail an emissions test, but it is essential to address the underlying issue to maintain proper engine performance and emissions control.