AutoCodes – Generic – U0442

U0442 Code - Invalid Data Received From ECM/PCM 'B'

Quick Answer

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Common causes include Faulty Engine Control Module (ECM)/Powertrain Control Module (PCM) 'B', ECM/PCM 'B' harness is open or shorted, ECM/PCM 'B' 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: U0442 indicates Invalid Data Received From ECM/PCM 'B'.
Common causes: Common causes include Faulty Engine Control Module (ECM)/Powertrain Control Module (PCM) 'B', ECM/PCM 'B' harness is open or shorted, ECM/PCM 'B' 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 35,943

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 Apr 11, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U0442 Description

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages are needed to be exchanged on the serial data circuits. Some devices are constantly receiving information from other devices through serial data communication network. The invalid data Diagnostic Trouble Code (DTC) will be set when a receiving device detects a discrepancy in the information it receives from the Engine Control Module (ECM)/Powertrain Control Module (PCM) 'B' causing its integrity to be questioned.

OBDII Code U0442 - Invalid Data Received From ECM/PCM 'B' - AutoCodes.com — U0442 Code - Invalid Data Received From ECM/PCM 'B'

What does this mean?

What are the Possible Causes of the DTC U0442?

Faulty Engine Control Module (ECM)/Powertrain Control Module (PCM) 'B'
ECM/PCM 'B' harness is open or shorted
ECM/PCM 'B' circuit poor electrical connection

How to Fix the DTC U0442?

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 U0442 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 U0442 code?

Need more information on how to fix the U0442 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0442 code diagnosed by a professional: Find a repair shop in your area

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 U0442 Code

What does the OBDII code U0442 mean?

The U0442 code means that invalid or corrupted data has been received from the ECM/PCM 'B,' indicating a communication issue between vehicle modules.

What are the common symptoms of the U0442 code?

Symptoms may include an illuminated check engine light, reduced engine performance, erratic transmission behavior, or failure of certain systems to operate correctly.

What causes the U0442 code to appear?

The code can be caused by faulty wiring or connectors, software glitches in the ECM/PCM 'B,' a defective module, or interference in the communication network.

Can a faulty ECM/PCM 'B' trigger the U0442 code?

Yes, a malfunctioning ECM/PCM 'B' that sends invalid or corrupted data can trigger this error code.

How do I diagnose the U0442 code?

Start by inspecting the wiring and connectors related to the ECM/PCM 'B,' check for other related codes, and use a scan tool to monitor the vehicle's communication network.

Can the U0442 code affect drivability?

Yes, depending on the severity of the issue, it can lead to drivability problems like reduced power, poor shifting, or system malfunctions.

Is the U0442 code serious?

While the car may still run, the U0442 code should be addressed promptly, as it may indicate a communication problem that could lead to more significant issues.

What tools are needed to fix the U0442 code?

You’ll typically need an OBDII scan tool, a multimeter for electrical checks, and possibly manufacturer-specific diagnostic software.

Can a software update fix the U0442 code?

Yes, if the issue is caused by a software glitch, reprogramming or updating the affected module may resolve the problem.

Should I clear the U0442 code after repairs?

Yes, after completing repairs, clear the code with an OBDII scanner and drive the vehicle to ensure the issue doesn’t return.

Discuss the causes and fixes for U0442 OBDII Code

Submit a New Comment

Patrick
Date: December 1, 2024 at 6:11 pm

Good afternoon, I recently swapped the engine on my mazda 6 sporrt 2015 due to theprevious engine running dry. I now have present code U0442 but no other codes, I have 5.0 ohms of recistance on my ground wire for my tcm. Could this be due to a reprograming issue? harness and its connections have been veriefied, cleaned and reinstallled. My ground wires are all connected and clean. The fuse for the starter motor, coming from the positive terminal battery burnt out, that was replaced but could a short have been caused causing damage to the fuse and pcm?

Reply to Comment
- OBDIITech
  Date: December 2, 2024 at 3:17 pm
  Hello! The U0442 code typically indicates an issue with invalid data received from another control module, often tied to communication errors in the vehicle's network. Given your situation:
  1. TCM Ground Resistance: 5.0 ohms is relatively high for a ground connection. Ideally, ground resistance should be close to 0 ohms. High resistance could cause communication issues, as the TCM may not be getting a clean ground. Verify and improve the ground connection by cleaning the contact points and ensuring a direct, solid connection to the chassis.
  2. Reprogramming Issue: If the engine or TCM isn't correctly programmed or adapted to the vehicle after the engine swap, it can cause U0442. Check with a dealership or a technician equipped with an OEM-level scan tool to ensure the modules are correctly programmed and synchronized.
  3. Burnt Starter Fuse: A short circuit that blew the starter fuse could potentially have damaged the PCM, TCM, or other sensitive electronic components if the short caused a voltage spike. It would be wise to inspect these modules for damage:
    
    Perform a visual inspection for burnt or swollen components.
    
    Use a scan tool to verify communication between the PCM, TCM, and other modules.
    
    Check for additional fault codes related to communication or voltage irregularities.
  4. Harness and Connections: You've verified and cleaned the harness, but double-check for any damaged or corroded pins, especially at the connectors for the TCM and PCM. A small defect can sometimes lead to significant communication problems.
  5. Next Steps:
    
    Repair the high resistance in the ground connection first.
    
    Confirm proper programming and synchronization of the TCM and PCM.
    
    If the problem persists, have the TCM and PCM tested for internal faults or damage caused by the short.
  Reply to Comment