AutoCodes – Chrysler – U1421 Chrysler

U1421 Chrysler 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 Chrysler 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 2,132

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

What does this mean?

What are the Possible Causes of the DTC U1421 Chrysler?

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 Chrysler?

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 Chrysler 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 Chrysler Code

1. What does the OBDII code U1421 for Chrysler mean?

The U1421 code indicates an issue with the Ignition Key Off Time Received that is deemed implausible by the vehicle's computer system.

2. What are the common symptoms associated with code U1421?

Common symptoms may include intermittent starting problems, engine stalling, and issues with the vehicle's immobilizer system.

3. What are the possible causes of the U1421 code?

Potential causes of the U1421 code can include a faulty ignition key, a problem with the key fob, issues with the immobilizer system, or a malfunction in the vehicle's electronic control module.

4. How can I diagnose the U1421 code?

Diagnosing the U1421 code typically involves using a diagnostic scanner to retrieve the code and checking the ignition system components for any visible damage or faults.

5. Can I still drive my vehicle with the U1421 code present?

It is not recommended to drive your vehicle with the U1421 code present, as it can lead to potential starting and stalling issues that may affect the safety and performance of the vehicle.

6. How can I repair the U1421 code?

Repairing the U1421 code may involve resetting the fault code with a diagnostic scanner, replacing the ignition key or key fob, checking and repairing any wiring or connection issues, or reprogramming the vehicle's electronic control module.

7. Do I need a professional mechanic to fix the U1421 code?

While some simple fixes like checking the key and resetting the code can be done by the vehicle owner, more complex issues related to the immobilizer system or electronic control module may require the expertise of a professional mechanic.

8. How much does it cost to repair the U1421 code?

The cost of repairing the U1421 code can vary depending on the underlying cause of the issue, the parts needed for replacement, and the labor costs charged by the mechanic or dealership.

9. Can the U1421 code reoccur after repairs?

If the root cause of the U1421 code is not properly addressed during repairs, it is possible for the code to reoccur. Therefore, it's essential to diagnose the issue accurately and fix it completely to prevent future occurrences.

10. Is the U1421 code a serious problem?

While the U1421 code may not always cause immediate vehicle breakdown, it can lead to starting and stalling issues that affect the drivability and safety of the vehicle. It is recommended to address the problem promptly to avoid further complications.