U0140 on 2009-2012 Dodge RAM 2500: Lost Communication with BCM Fixes

What's Unique About the 2009-2012 Dodge RAM 2500

What makes the 2010-2012 Dodge RAM 2500 unique regarding the U0140 code is the high likelihood of it being a software glitch rather than a hardware failure. Multiple Technical Service Bulletins (TSBs) issued by the manufacturer confirm that this code can be 'erroneous' and will not clear with a standard scan tool until the PCM's software is updated. This is a crucial distinction from the 2009 model year, which is part of the previous generation and is more likely to suffer from traditional wiring or module failures when this code appears. The TIPM (fuse box) is also a well-documented failure point on these trucks, which can cause communication codes.

Diagnostic Flowchart

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

Generation note: This year range covers two RAM generations. The 2009 model is the last of the 3rd Generation (DH), while 2010-2012 models are part of the 4th Generation (DJ). The software-related TSBs specifically reference the 4th generation models, making a PCM reflash the primary fix for them. For the 2009 model, diagnosis should focus more on wiring, grounds, and hardware like the TIPM and BCM.

Symptoms You May Notice

• Check Engine Light (MIL) is on.
• Inability to clear the U0140 code with a standard OBD-II scanner, often showing as a 'permanent' DTC. [Bulletin #18-092-15, Bulletin #18-097-15]
• Erratic or non-functional power windows, door locks, or interior/exterior lights.
• Malfunctioning windshield wipers.
• Other warning lights (ABS, traction control, airbag) may illuminate simultaneously.
• Parking lights stay on even when the truck is off.
• In some cases, no symptoms are present other than the stored code.

Most Likely Causes

1. PCM Software Requires Update 🔴 High Probability Multiple manufacturer TSBs for 2010-2012 models identify an erroneous U0140 code that is resolved by updating the PCM software. [Bulletin #1810016, Bulletin #18-097-15] This is a widely discussed issue in owner forums.
   How to confirm: A standard scan tool will be unable to clear the code. A dealer or a shop with advanced tools (like wiTECH) can check the current software calibration ID against the latest available from the manufacturer as listed in the TSBs.
   Typical fix: Reprogramming the Powertrain Control Module (PCM) with the latest software version. This must be done by a dealer or a properly equipped independent shop.
   Est. part cost: $0
2. CAN Bus Wiring or Connector Fault 🟡 Medium Probability Wiring harnesses, particularly in areas like the A-pillar, doors, or under the fuse box (TIPM), can become damaged, corroded, or chafed over time, causing an open or short in the CAN bus circuit.
   How to confirm: Visually inspect wiring harnesses between the PCM, BCM, and TIPM for damage. Check connectors for bent, loose, or corroded pins. A multimeter can be used to check for continuity and shorts in the CAN high and low circuits. A key test is measuring resistance between pins 6 (CAN-H) and 14 (CAN-L) on the OBD-II port (with the battery disconnected); a healthy network should read approximately 60 ohms.
   Typical fix: Repairing the damaged section of the wiring harness or cleaning/replacing the faulty connector. Applying dielectric grease to connectors can prevent future corrosion.
   Est. part cost: $10-$50
3. Failing Body Control Module (BCM) ⚪ Low Probability → Shop Body Control Module While less common than software or wiring issues, the BCM itself can fail internally due to moisture intrusion, vibration, or age.
   How to confirm: This is typically diagnosed by exclusion. If the PCM software is up-to-date and all wiring, power, and grounds to the BCM are confirmed to be good, the BCM is the likely culprit. An advanced scan tool may show the BCM as completely offline or non-responsive.
   Typical fix: Replacing the Body Control Module. Replacement modules often need to be programmed to the vehicle's VIN.
   Est. part cost: $300-$600

Rare But Worth Checking

• Faulty Totally Integrated Power Module (TIPM): → Shop Fuse Box The TIPM (the main fuse box) is a notorious failure point on these trucks and acts as a central communication gateway. Internal failures can disrupt communication between modules, leading to a U0140 code. Symptoms of a failing TIPM on 2011-2012 models include issues with the fuel pump, door locks, and wipers. 🎬 See common TIPM failure symptoms and how to replace it. One owner on RamForum.com traced their U0140 issue to a fuse for a module not making good contact in the fuse box.
• Low Battery Voltage or Poor Grounds: → Shop Vehicle Battery Control modules are sensitive to voltage. A weak battery, failing alternator, or corroded ground connection can cause intermittent communication errors across the network. Ram trucks from this era are known to be very sensitive to battery issues. Always check the battery and charging system health before diving into complex diagnostics.
• Aftermarket Accessory Interference: Improperly installed aftermarket accessories, such as remote starters, alarms, or radios, can interfere with the CAN bus network if they are tapped into the wrong circuits. This can introduce noise or draw unexpected voltage, causing modules to lose communication.

Diagnosis Steps

1. Connect a scan tool and attempt to clear the U0140 code. If the code is 'permanent' and will not clear, this strongly suggests the software issue described in the TSBs for 2010-2012 models.
2. Check for manufacturer TSBs related to U0140 for your specific vehicle year and VIN. TSBs #18-092-15, #18-093-15, and #18-097-15 are key for this platform.
3. If TSBs point to a software update, have a dealer or qualified shop perform the PCM reflash. Ensure they use a battery charger to maintain stable voltage (13.2-13.5V) during the flash.
4. If no TSBs apply or the reflash does not fix the issue, check the battery and charging system. Ensure battery voltage is above 12.4V with the engine off and between 13.2-14.5V with the engine running.
5. Inspect all power and ground connections to the BCM and PCM. Clean any corrosion. Check fuses related to the BCM and other modules for a secure fit.
6. Visually inspect the wiring harness between the PCM, BCM, and TIPM for any signs of physical damage, chafing, or corrosion, paying close attention to door jambs and under-dash areas.
7. With the battery disconnected, use a multimeter to check the resistance of the CAN bus network at the OBD-II port (pins 6 and 14). It should be approximately 60 ohms. A reading of 120 ohms suggests an open circuit or a missing terminating resistor, while 0 ohms indicates a short circuit.
8. If the CAN bus resistance is incorrect, begin unplugging modules one by one (starting with easily accessible ones like the ABS module or radio) to see if the resistance returns to normal, which would isolate the faulty module or wiring branch.
9. If all wiring, power, grounds, and network resistance are confirmed good, the fault is likely with a control module, such as the TIPM or BCM.

Parts You'll Likely Need

• Body Control Module (BCM) (OEM #4692281 (For 2011 models, may be listed as FCM/BCM)) — This module is the most likely hardware component to fail if a software update or wiring repair does not resolve the code. It controls many of the vehicle's body electrical functions.
  Trusted brands: Mopar
  OEM price range: $400-$600
  Aftermarket price range: $250-$450

Related Codes That Often Appear With This One

• P0300 — A TSB specifically links U0140 with P0300 (Multiple Cylinder Misfire) on 2012 models, indicating a software update addresses both. [Bulletin #1810016]
• P0032 — A TSB for 2011 models notes that U0140 may appear alongside P0032 (O2 Sensor 1/1 Heater Circuit High). [Bulletin #18-092-15]
• P050D — A TSB for 2010 models notes that U0140 may appear with P050D (Cold Start Rough Idle). [Bulletin #18-093-15]
• P0455 / P0456 — An owner on RamForum.com reported these EVAP leak codes appeared simultaneously with U0140 and were resolved by fixing a bad fuse connection to a module.

Technical Service Bulletins (TSBs) & Recalls

• Bulletin #1810016: Notes U0140 on 2012 models and points to a software update.
• Bulletin #18-092-15: Mentions U0140 on 2011 models and states that attempting to clear the DTC will be unsuccessful.
• Bulletin #18-093-15: Cites U0140 as an erroneous DTC on 2010 5.7L models that cannot be cleared.
• Bulletin #18-097-15: Explicitly states the fix for an unclearing U0140 on 2012 models is reprogramming the PCM.
• Bulletin #18-102-15: Also confirms for some 2012 models that U0140 will be unsuccessful to clear without a flash.

Platform-Specific Known Issues

• On 2010-2012 models, the U0140 code is frequently an 'erroneous' or 'ghost' code that cannot be cleared without a dealer-level software update to the PCM, as documented in multiple TSBs.
• A real-world fix reported on RamForum.com for a 2014 model with U0140 and other electrical gremlins was a poorly

Mechanic-Grade Diagnostic Values

• CAN Bus Network Resistance — expected: Approximately 60 Ω (Ohms) across pins 6 (CAN-H) and 14 (CAN-L) of the OBD-II port with the battery disconnected.. Failure: A reading of ~120 Ω indicates an open circuit or a fault in one of the two terminating resistors. A reading near 0 Ω indicates a short between the CAN-H and CAN-L wires.
• BCM Power Supply Voltage — expected: 12.2 - 12.8 V at the BCM power input connector with the ignition on.. Failure: Significantly lower voltage points to a problem with the fuse, wiring, or TIPM supplying power to the BCM.
• BCM Ground Resistance — expected: < 0.1 Ω between the BCM ground pin and a clean chassis ground.. Failure: Higher resistance indicates a corroded or loose ground connection, a common cause of intermittent communication faults.
• Battery Voltage During PCM Flash — expected: Must be maintained between 13.2 and 13.5 volts.. Failure: Voltage dropping below 13.2V or climbing above 13.5V can interrupt or corrupt the reprogramming process, potentially disabling the PCM.

Scan Tool Commands That Help

• wiTECH: Reprogram PCM — This is the primary repair procedure for the common 'ghost' U0140 code on 2010-2012 models as specified by multiple TSBs. The code is often stored as permanent and cannot be cleared by normal means until the PCM software is updated.
• wiTECH: Clear All DTCs — After a successful PCM reflash, the wiTECH application will automatically present all DTCs that were set during the process and allow the technician to clear them. This is a necessary final step.

Wiring & Ground Locations

• TIPM Connectors C1-C10 — Located on the bottom of the Totally Integrated Power Module (TIPM) in the engine bay, on the left front fender.. The TIPM is a central communication hub. Corrosion or damage to the pins in these connectors, especially the CAN bus pins, can sever communication with the BCM. The connectors are not well-sealed and are prone to corrosion from moisture.
• CAN C and CAN IHS Hubs — Located under the gauge cluster, near the steering wheel shaft.. These are junction points for the vehicle's communication networks. A fault at one of these hubs can disrupt messages between multiple modules, including the PCM and BCM. Technicians can tap into these for diagnostics or to isolate parts of the network.
• Ground Pack G314 (example) — Various ground packs and eyelets are located throughout the vehicle. A 2010 HD Ram diagram shows multiple ground points like G104, G105 (engine area) and G210, G211 (cabin area).. The BCM and other modules rely on clean, solid ground connections. A corroded or loose ground can cause intermittent voltage drops and communication errors, leading to a U0140 code.

Real Owner Repair Stories

• Reddit user u/ogag79 (2014 Dodge (model not specified, but symptoms are relevant)) — After driving through axle-deep water, the instrument cluster started blinking with multiple errors (ABS, power steering, shifter). Code U0140 was present. Power steering would be lost after restarting the vehicle.
  ❌ Tried (didn't work) Letting the vehicle dry out provided a temporary fix, but the issue returned after 15 minutes of driving.
  ✅ What actually fixed it The user identified that a worn rubber seal on the windshield cowl was allowing rain water to seep into the engine bay, likely affecting wiring or modules. The problem started immediately after driving through a flood, strongly indicating water intrusion as the root cause. The final repair was not posted, but the diagnosis points to repairing the water leak and checking/repairing affected connectors/modules.

OEM Part Supersession History

• 4692281 → Unknown, but multiple revisions exist. — Part updates to fix bugs or improve reliability.
  Heads up: The part number 4692281 is listed for 2011 Ram 1500/2500/3500 models and is often referred to as the FCM/BCM. It is critical to match the part number exactly when replacing, as different numbers may have different internal hardware or software, even if they physically fit.

Model Year Variations Within This Range

• 2009: As a 3rd Generation (DH) truck, the 2009 model is less likely to be affected by the software glitches noted in the TSBs for 4th Gen models. Diagnosis should prioritize wiring, grounds, and potential hardware failure of the TIPM or BCM.
• 2010-2012: These 4th Generation (DJ) models are specifically called out in multiple TSBs where an 'erroneous' U0140 is fixed with a PCM software update. This should be the first diagnostic path for these years if the code cannot be cleared with a standard scanner. [Bulletin #1810016, Bulletin #18-097-15]