B1342: ECU / Control Module Is Defective
4 vehicles · 2 makes · $30-$1,400 repair
Most Reported On
B1342 is an OBD-II diagnostic trouble code meaning “ECU / Control Module Is Defective.” This is a manufacturer-specific body code (common on Ford and other makes) generally meaning a control module has detected an internal fault and considers itself defective. It can be set by a true internal hardware/software failure of the module or, very often, by power and ground problems such as low battery voltage that make the module behave abnormally. Because the symptoms depend on which module set it, behavior varies widely. Before replacing any module, supply voltage, grounds, and connections should be verified first. This code is most commonly reported on 2015-2020 Ford Transit, 2003-2011 Lincoln Town Car (Executive, Signature, Cartier, Designer, Signature L), and 2005-2010 Ford Mustang, plus 1 other vehicle, with repair costs ranging from $30 to $1,400.
Common Causes
Typical Repair Cost
Based on 4 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose B1342, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (4)
Body Control Module (BCM) Failure Causing Intermittent Electrical Gremlins
2005-2010 Smart Junction Box Water Intrusion Causing Wiper, Lighting, and Electrical Malfunctions
Door Ajar Warning False Alarm and Interior Lights Staying On
FAQ
What does B1342 mean?
B1342 stands for "ECU / Control Module Is Defective." This is a manufacturer-specific body code (common on Ford and other makes) generally meaning a control module has detected an internal fault and considers itself defective. It can be set by a true internal hardware/software failure of the module or, very often, by power and ground problems such as low battery voltage that make the module behave abnormally. Because the symptoms depend on which module set it, behavior varies widely. Before replacing any module, supply voltage, grounds, and connections should be verified first.
What are the most common causes of B1342?
The most common causes of B1342 are: Low or unstable battery/system voltage, Poor power or ground connection to the module, Corroded or loose module connectors, Corrupted module software/configuration, Internal module hardware failure, Recent electrical work or battery disconnection issues. The specific cause varies by vehicle.
How much does it cost to fix B1342?
Repair costs for B1342 range from $30 to $1,400, depending on the vehicle and root cause.
Which vehicles are affected by B1342?
Au7o has documented B1342 across 4 vehicle models from 2 manufacturers: Ford, Lincoln.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.