U0140 on 2013-2015 Dodge Dart: Lost Communication With Body Control Module Fixes

What's Unique About the 2013-2015 Dodge DART

The Dodge Dart, based on a Fiat architecture, was known for having sensitive electrical systems, especially in its early 2013-2014 models. For this specific vehicle, the U0140 code is frequently cited in Technical Service Bulletins (TSBs) alongside a list of other seemingly unrelated engine and transmission codes. This pattern strongly suggests that many instances of U0140 are not caused by a hardware failure but by a software issue that can be resolved with a PCM update at a dealership. Furthermore, owner forums and repair videos highlight issues like corroded fuse boxes and grounds 🎬 Watch: How a bad ground can cause a no-start condition. as common culprits for a host of electrical problems, including this code. The Fiat architecture also necessitates a 'Proxy Alignment' procedure with a capable scan tool after replacing almost any module on the network to prevent communication errors.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• Malfunctioning or inoperative power windows, door locks, or mirrors
• Erratic interior or exterior lights (e.g., headlights staying on)
• Wipers operating incorrectly or not at all
• Issues with the keyless entry or anti-theft system, potentially causing a no-start
• Multiple warning lights on the dashboard (ABS, Traction Control, Airbag, etc.)
• Poor or slow acceleration, or car entering 'limp mode'
• Instrument panel flickering wildly or going haywire
• Radio display asking for security code or having blacked-out spots
• Brakes not working correctly and 'Service Electronic Brake System' message on dash

Most Likely Causes

1. Low or Unstable Battery Voltage 🔴 High Probability The 2013 Dodge Dart is noted for battery and electrical problems, with owners reporting premature battery failure that can cause a cascade of electronic issues. Low voltage is a very common cause for network communication codes across all modern vehicles, as modules require stable power to communicate.
   How to confirm: Test the battery voltage with a multimeter. It should be above 12.4V with the engine off. Have the battery load-tested at an auto parts store to check its health, as a battery can show good voltage but fail under load.
   Typical fix: Recharge or replace the vehicle's battery.
   Est. part cost: $150-$300
2. Software Glitch Requiring PCM/BCM Update 🔴 High Probability Manufacturer TSBs #18-022-17 REV. A and #18-023-16 explicitly list U0140 as one of several codes that are resolved by reprogramming the Powertrain Control Module (PCM). Additionally, TSB #08-128-15 was issued for 2012-2013 Darts with the 2.0L engine to update BCM software for remote start and hard-start issues.
   How to confirm: A Dodge dealership or a well-equipped independent shop with a tool like wiTECH can check if your vehicle's software is up to date and if a proxy alignment is needed.
   Typical fix: Reprogramming (flashing) the PCM or BCM with the latest software version.
   Est. part cost: $0 (if under warranty) - $200
3. Damaged Wiring or Poor Connection 🟡 Medium Probability CAN bus communication relies on a twisted pair of wires. A short to ground, short to power, or an open in this circuit will disrupt communication. A user on the r/dodgedart forum resolved a no-start with U0140 by finding a forgotten connector in the fuse box after a transmission replacement, highlighting the sensitivity to loose connections. Corrosion in the under-hood fuse box is also a documented issue.
   How to confirm: Visually inspect the wiring harness leading to the BCM, which is located behind the driver's side lower dash panel. Check all connectors in the under-hood fuse box for looseness or corrosion. Advanced diagnosis involves testing CAN bus resistance (should be ~60 ohms with battery disconnected) and checking for proper voltage signals with a multimeter or oscilloscope.
   Typical fix: Repairing the damaged section of the wiring harness or cleaning/re-seating the connectors. This can range from plugging in a forgotten connector to repairing a corroded fuse box.
   Est. part cost: $10-$500 (depending on whether a simple repair or a harness/fuse box replacement is needed)
4. Failed Body Control Module (BCM) ⚪ Low Probability While the module itself can fail, it's less common than wiring, power, or software issues. It should be considered only after other causes are ruled out. Water intrusion is a common killer of BCMs.
   How to confirm: Use a high-end scan tool to attempt direct communication with the BCM. If it's unresponsive and has proper power and ground confirmed with a multimeter, the module is likely faulty. A technician on Reddit noted that a proxy alignment procedure with a capable scanner is a necessary step after flashing or replacement.
   Typical fix: Replacing the BCM and programming the new unit to the vehicle using a capable scan tool.
   Est. part cost: $200-$400

Rare But Worth Checking

• Corroded Under-hood Fuse Box:
• Interference from Aftermarket Electronics:

Diagnosis Steps

1. Check for any Technical Service Bulletins (TSBs) related to your VIN and this code. TSBs #18-022-17 REV. A, #18-023-16, and #08-128-15 are known to address U0140 or related symptoms with software updates.
2. Test the battery and charging system. Ensure the battery is fully charged and passes a load test. Weak or failing batteries are a primary cause of communication faults on Darts.
3. Inspect all fuses related to the BCM. On a Dart, these are typically large fuses (F01, F02, F06) located in the under-hood fuse box.
4. Visually inspect the wiring harness connected to the Body Control Module (BCM). The BCM is located under the driver's side dashboard, to the left of the steering column. 🎬 Watch this video to find and replace the BCM module. Look for any signs of damage, chafing, or corrosion, especially from water leaks.
5. Thoroughly inspect the under-hood fuse box for corrosion on terminals and relays, as this is a known failure point.
6. If any recent repairs (especially transmission work) have been performed, double-check all connectors in the engine bay, particularly around the fuse box, to ensure they are fully seated.
7. If you have an advanced scan tool (like AlfaOBD or wiTECH), check the CAN bus network list to see which modules are online. If the BCM is not communicating, the issue is likely power, ground, or the module itself.
8. If multiple communication codes are present, perform a 'Proxy Alignment'. This procedure re-establishes communication and configuration between all modules on the network and is often required after replacing a module.

Parts You'll Likely Need

• Battery — A weak or failing battery is a very common cause of network communication codes on the Dodge Dart.
  Trusted brands: Mopar, Interstate, DieHard
  OEM price range: $200-$300
  Aftermarket price range: $150-$250
• Body Control Module (BCM) (OEM #68189480AG) — If wiring, power, and software are all confirmed to be good, the BCM itself may have failed. This is a last resort replacement. Part number 68189480AE was superseded by 68189480AG.
  Trusted brands: Mopar
  OEM price range: $250-$400
  Aftermarket price range: $150-$300 (Used/Remanufactured)

Related Codes That Often Appear With This One

• P0520 — As seen in NHTSA complaint #11281059, this 'Engine Oil Pressure Sensor Circuit' code can appear with U0140. This may indicate a shared wiring harness problem or a general electrical issue affecting multiple systems.
• P0116, P0441, P1D73, P2172, U0402 — These codes are listed alongside U0140 in TSBs #18-022-17 REV. A and #18-023-16. Their presence together strongly points to the software update fix mentioned in the bulletins.
• B2204 — A Reddit user reported this 'ECU Configuration Mismatch' code along with U0140 when their dash lit up with warnings. This combination points to a network integrity or module configuration problem, often resolved with a 'Proxy Alignment' procedure using an advanced scan tool.

Technical Service Bulletins (TSBs) & Recalls

• 18-022-17 REV. A: Recommends a PCM software update to fix a group of codes including U0140.
• 18-023-16: Also recommends a PCM software update to address a list of diagnostic trouble codes, U0140 among them.
• 08-128-15: Supersedes an earlier TSB and calls for a BCM software update on 2012-2013 Darts (2.0L) to fix engine start/stall issues.

Platform-Specific Known Issues

• NHTSA Technical Service Bulletin #18-022-17 REV. A and #18-023-16 indicate that for some 2013-2015 Darts, code U0140 can be triggered by a software issue and is resolved by reprogramming the PCM.
• Owner complaints, like NHTSA ODI #11281059, show U0140 appearing with other electrical codes like P0520 (Engine Oil Pressure Sensor), suggesting widespread electrical gremlins or harness issues on some vehicles.
• TSB #08-128-15 specifically targets 2012-2013 Darts with the 2.0L engine for a BCM software update to fix remote start and hard-starting problems.
• Corrosion within the main under-hood fuse box is a documented problem that can cause a loss of power or ground to multiple modules, leading to U0140 and other codes.

Mechanic-Grade Diagnostic Values

• CAN Bus Network Resistance — expected: Approximately 60 Ω. Failure: A reading of ~120 Ω indicates an open circuit or one of the two terminating resistors is offline. A reading near 0 Ω indicates a short between the CAN High and CAN Low wires.
• CAN Bus Voltage (Key On, Engine Off) — expected: CAN High (Pin 6 to ground): ~2.6V. CAN Low (Pin 14 to ground): ~2.4V.. Failure: Significant deviation from these voltages, or voltage that doesn't change, points to a short, open, or a faulty module transceiver.
• BCM Power Supply Voltage — expected: 12.2V - 12.8V. Failure: Low or no voltage indicates a problem with the fuse, wiring, or power source leading to the BCM.
• BCM Ground Resistance — expected: < 0.1 Ω. Failure: High resistance indicates a corroded or loose ground connection, a very common issue on this platform.

Scan Tool Commands That Help

• wiTECH or AlfaOBD: Proxy Alignment (PROXI) — This procedure is mandatory after replacing the BCM or almost any other module on the CAN network. It is also used to resolve a flashing odometer or when multiple U-codes appear after a repair. It reconfigures the list of installed modules on the network.
• wiTECH: Restore BCM Proxi Configuration — This is a step used in conjunction with a BCM software flash or replacement. It restores the vehicle's specific configuration (options like remote start, etc.) to the BCM before the network-wide alignment is performed.
• wiTECH or advanced scan tool: Network Topology / ECU List — At the start of diagnosis, this function shows which modules are currently online and communicating. If the BCM is missing from this list, it confirms it is offline and helps focus troubleshooting on its power, ground, and direct connections.

Wiring & Ground Locations

• BCM Location — Under the driver's side dashboard, to the left of the steering column. It is integrated with the interior fuse panel/power distribution center.. This is the central component for this fault code. Physical inspection for loose connectors, water damage, or corrosion is a key diagnostic step.
• G905A / G900 — Main body ground points located under the driver's side of the dashboard, near the A-pillar and kick panel area.. These are primary ground points for the BCM and other interior electronics. A loose or corroded connection here can cause floating voltages and intermittent communication failures, including U0140.
• Engine/Transmission Ground Strap — A braided or solid wire connecting the engine or transmission case to the vehicle's chassis/frame, often located under the battery tray or on the driver's side frame rail.. A corroded or loose main engine ground can cause widespread electrical havoc, as modules struggle to find a stable ground path. This can manifest as communication codes like U0140, especially during high-current events like starting.
• BCM Connector C4 - CAN C Pins — This is one of the main connectors on the BCM. The high-speed CAN C bus wires are typically located here.. The CAN C (+) and CAN C (-) wires are the direct communication lines to the BCM. Probing for voltage or resistance at these specific pins can confirm if the network signal is reaching the module. Wiring diagrams identify these as pins 45 and 46 in some configurations.
• C200 Connector — A large, main wiring harness connector, often located at the firewall, connecting the engine bay harness to the interior dash harness.. This connector is a major junction for the CAN bus. Corrosion or a backed-out pin within this connector can sever communication between the engine/transmission controllers and the BCM.

Real Owner Repair Stories

• YouTube channel 'Dodge Dart No Crank No Start - Fixed for $0.00 - Bad Ground' (2013 Dodge Dart 2.0L) — No crank, no start condition after being driven to a store.
  ❌ Tried (didn't work) Replacing the starter motor.
  ✅ What actually fixed it The main ground wire going from the frame to the engine block was found to be heavily corroded. Cleaning the connection points on the frame rail and the engine block to restore a solid ground path resolved the no-start issue.
• Reddit user in r/dodgedart (2013 Dodge Dart) — Persistent U0140 code, ABS light on.
  ❌ Tried (didn't work) Replacing the oil pressure sensor for other codes.
  ✅ What actually fixed it A mechanic discovered a frayed wire in the harness above the wheel hub. This wire was related to the ABS system, but fixing it also cleared the U0140 code, indicating a shared harness or network issue.
• YouTube channel 'How to fix ABS Pump U0140 for 2013 Dodge Dart' (2013 Dodge Dart 2.0L) — ABS light on, code U0140 present, and a code indicating a bad ABS pump.
  ❌ Tried (didn't work) Initial diagnosis pointed to replacing the ABS pump.
  ✅ What actually fixed it The mechanic physically tapped the ABS pump motor with a socket extension, similar to tapping a stuck starter motor. This temporarily unstuck the motor, the ABS light went out after a code reset, and communication was restored. This points to an intermittent mechanical failure within the ABS pump motor causing it to drop off the network.

OEM Part Supersession History

• 68189480AC → 68189480AD, 68189480AE — Standard part revisions for software updates and hardware improvements.
  Heads up: A replacement BCM must be programmed to the vehicle's VIN and specific configuration. An incorrect part number or failure to program will result in a no-start condition or malfunctioning features. A Proxy Alignment is mandatory after installation.

Model Year Variations Within This Range

• 2012-2013: TSB #08-128-15 specifically targets 2012-2013 Darts with the 2.0L engine for a BCM software update to fix hard-start and remote-start stalling issues. This suggests earlier models had specific software logic that was corrected in later years.