U0101 on 2013-2016 Dodge Dart: Lost Communication with TCM Causes and Fixes

What's Unique About the 2013-2016 Dodge Dart

The Dodge Dart, particularly models with the 1.4L Turbo engine and dual-dry clutch transmission (DDCT), is known for TCM-related issues. A specific recall (NHTSA #15V542) was issued for 2013-2015 models because the TCM's mounting bracket could put stress on the module's internal circuit board solder joints, causing an electrical open and failure. This failure results in the transmission unexpectedly shifting into neutral. Furthermore, the TCM is unusually located inside the cabin, under the carpet in the passenger footwell, which can make its connectors vulnerable to moisture or physical damage from passenger feet or misplaced items. One owner noted the issue seemed to happen more frequently with a passenger in the car, suggesting a potential link to pressure on the floorboard above the module. Poor chassis and engine grounds are also a widely reported problem on this platform, often causing intermittent electrical issues and communication codes.

Symptoms You May Notice

• Check Engine Light is on
• Transmission or other warning lights illuminated on the dash (e.g., Active Stability Control)
• Vehicle is stuck in 'limp mode' (will not shift out of a single gear, usually 2nd or 3rd)
• Harsh, erratic, or delayed shifting
• Inability to shift out of Park or Neutral
• Sudden shift to Neutral while driving
• Gear position indicator (PRNDL) on the dash is blank or incorrect
• Vehicle may not start or may stall
• Scan tool cannot communicate with the TCM

Most Likely Causes

1. Failed Transmission Control Module (TCM) 🔴 High Probability → Shop Transmission Assembly A known weak point, especially on 2013-2015 models with the 1.4L engine and dual-clutch transmission. Recall 15V-542 (FCA #R42) was issued because the mounting bracket could crack internal solder joints on the TCM's circuit board. General electronic failure is also common.
   How to confirm: Use an advanced scan tool to check for communication with the TCM. If the TCM is unresponsive and its power, ground, and CAN bus wiring are confirmed to be good, the module itself has failed. This code is often seen with P0700. NHTSA ODI #11203743 describes a case where several modules stored code U0101-00 for lost communication, eventually requiring the TCM to be replaced and reprogrammed.
   Typical fix: Replace the Transmission Control Module and its mounting bracket. 🎬 Watch: Step-by-step TCM removal and replacement guide The new TCM must be programmed to the vehicle by a dealer or qualified shop using a Proxy Alignment procedure. The recall remedy includes replacing both the TCM and the bracket free of charge for affected VINs.
   Est. part cost: $400-$800
2. Wiring or Connector Issues 🟡 Medium Probability The TCM is located in the passenger footwell, where its connectors can be susceptible to moisture, corrosion, or physical damage from kicks or misplaced items. The CAN bus wiring harness can also chafe or break elsewhere in the vehicle. An owner on DodgeForum.com diagnosed a U0101 that only occurred in cold weather, pointing to a potential wiring or solder joint issue that was temperature-sensitive.
   How to confirm: Visually inspect the wiring and connectors at the TCM for damage, corrosion, or loose pins. Check for fluid intrusion in the connector. Perform a continuity and resistance check on the CAN bus wires between the TCM and the OBD-II port/other modules.
   Typical fix: Repair or replace the damaged section of the wiring harness. Clean or replace corroded connectors. Ensure connectors are fully seated.
   Est. part cost: $10-$150
3. Low Battery Voltage or Poor Grounds 🟡 Medium Probability → Shop Vehicle Battery Dodge Darts are known for having poor grounding points from the factory, which can corrode and cause a wide range of intermittent electrical and communication problems. Key problem areas include the main chassis ground on the driver's side frame rail and the engine ground on the passenger strut tower.
   How to confirm: Test the battery voltage with a multimeter; it should be above 12.4V with the engine off. Test the charging system; it should be 13.5-14.5V with the engine running. Low voltage can cause various modules to drop off the communication network. Locate, disassemble, and clean the main battery-to-chassis and engine-to-chassis ground connections, as high resistance at these points is a common cause of communication errors.
   Typical fix: Charge or replace the battery. Disassemble, clean all contact surfaces with a wire brush, and re-secure chassis and engine ground connections. Replace corroded ground straps. Replace the alternator if it's not charging correctly.
   Est. part cost: $0-$250
4. Blown TCM Fuse ⚪ Low Probability
   How to confirm: Locate the fuses for the TCM in both the under-hood and interior fuse boxes and check for continuity. A blown fuse indicates a loss of power to the module, which will cause a communication failure. On a 2013 Dart, relevant fuses in the under-hood box can include F15 and in the interior box, F25. 🎬 Watch: How to locate the TCM and transmission fuses
   Typical fix: Replace the blown fuse. If the fuse blows again immediately, it indicates a short circuit in the wiring or a failed TCM that needs to be diagnosed further.
   Est. part cost: $1-$5

Rare But Worth Checking

• Faulty Totally Integrated Power Module (TIPM): → Shop Fuse Box The TIPM is the main fuse box and power distribution center. On Chrysler products, an internal failure can cause intermittent power loss to various modules, including the TCM, leading to communication codes like U0101. This is often accompanied by other random electrical issues.

Diagnosis Steps

1. Scan for All Codes: Use an advanced scan tool capable of reading codes from all modules (TCM, BCM, ABS, etc.), not just the engine computer. Note all codes present and see which other modules, if any, are reporting a loss of communication with the TCM.
2. Check Battery and Fuses: Verify the battery has a full charge (12.4V+) and the charging system is working correctly (13.5-14.5V). A weak battery is a common cause of communication codes. Visually inspect and test all fuses related to the transmission and TCM, such as F15 (underhood) and F25 (interior).
3. Inspect and Clean Grounds: This is a critical step for the Dart. Locate the main chassis ground behind the driver's side wheel well on the frame rail and the engine ground on the passenger strut tower. Disconnect the battery, then disassemble, wire brush all contact points until shiny, and securely reassemble these ground connections.
4. Inspect TCM Wiring: Locate the TCM in the passenger-side footwell, under the carpet near the center console. Disconnect the battery. Unplug the TCM connectors and inspect for any signs of corrosion, moisture, bent/damaged pins, or physical damage from being kicked.
5. Verify Power and Ground at TCM: Using a wiring diagram and multimeter, confirm power and ground at the TCM connector. For the DDCT, check for battery voltage (>12V) on the Fused B(+) wire (typically Yellow/Red) and for good ground (<0.5 ohms to chassis) on the Ground wire (typically Black).
6. Check CAN Bus Circuit: With the battery disconnected, measure the resistance between the two CAN bus wires (CAN-C High and CAN-C Low) at the diagnostic port (Pins 6 and 14). It should be approximately 60 ohms. A reading of 120 ohms indicates an open circuit or a terminating resistor is offline. A reading near 0 ohms indicates the wires are shorted together.
7. Isolate the Module: If all wiring, power, and grounds are good, but the TCM still won't communicate, the module itself is the most likely cause.
8. Professional Programming: If the TCM is replaced, it must be programmed to the vehicle's VIN by a dealership or a shop with the appropriate tools. This requires a 'Proxy Configuration Alignment' procedure.

Parts You'll Likely Need

• Transmission Control Module (TCM) (OEM #68210293AA) — This is the most frequent point of failure for code U0101 on the Dodge Dart, especially those with the dual-clutch transmission subject to recall 15V-542.
  Trusted brands: Mopar
  OEM price range: $500-$800
  Aftermarket price range: $400-$600 (Remanufactured)

Related Codes That Often Appear With This One

• P0700 — P0700 is a generic code set by the Engine Control Module (ECM) to indicate that the TCM has stored a fault. U0101 is one of the specific faults that can cause a P0700 to be logged.
• U0140 — Lost Communication with Body Control Module (BCM). If multiple 'U' codes are present, it often points to a wider network problem, like a fault on the main CAN bus wiring or a failing TIPM, rather than a single module failure.

Technical Service Bulletins (TSBs) & Recalls

• NHTSA Campaign ID: 15V542000 - Recall for faulty TCM mount that can cause internal circuit board failure.

Platform-Specific Known Issues

• NHTSA Recall 15V-542 (FCA #R42): Affects 2013-2015 Dodge Darts with the 1.4L engine and dual dry-clutch transmission (DDCT). The TCM mounting bracket can cause stress on the module's internal circuit board solder joints, leading to an electrical open and a sudden shift to neutral. The fix involves replacing both the TCM and the mounting bracket.
• NHTSA Recall 19V-293: Affects 2013-2016 Darts with automatic transmissions. The shifter cable bushing may deteriorate, allowing the cable to detach from the transmission. This can prevent the vehicle from being placed in Park, even if the shifter indicates it is. While not a direct cause of U0101, it is a critical transmission-related recall for this vehicle.

Mechanic-Grade Diagnostic Values

• CAN Bus Network Resistance — expected: ~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.
• TCM Power Supply Voltage (DDCT Models) — expected: >12.0 Volts. Failure: Voltage below 12.0V or 0V indicates a problem with the fuse (e.g., F15 underhood) or the power supply wire.
• TCM Ground Circuit Resistance (DDCT Models) — expected: < 0.5 Ω. Failure: Resistance higher than 0.5 Ω indicates a poor ground connection, which is a common issue on this vehicle.
• CAN Bus Voltage (Live Data) — expected: CAN High (Pin 6): Fluctuating between 2.5V and 3.5V. CAN Low (Pin 14): Fluctuating between 2.5V and 1.5V.. Failure: Voltages that are stuck high, low, or biased significantly away from the 2.5V center point can indicate a short to power/ground or a faulty module dragging the network down.

Scan Tool Commands That Help

• wiTECH or AlfaOBD: Proxy Configuration Alignment — This procedure is mandatory after replacing the TCM or almost any other major electronic module. It synchronizes the vehicle's configuration across the entire CAN network. Failure to perform this will result in a flashing odometer and persistent communication faults.
• wiTECH or advanced Autel/Snap-on: TCM Quick Learn / Clutch Point Learn — After replacing and programming a TCM on a vehicle with the Dual Dry-Clutch Transmission (DDCT), these functions must be run to allow the new module to learn the clutch engagement points and shifting parameters.

Wiring & Ground Locations

• TCM Location — Inside the cabin, under the carpet in the front passenger footwell, near the center console.. This location makes the module and its connectors vulnerable to moisture from wet shoes, spilled drinks, or a leaking heater core, as well as physical damage from being kicked.
• Main Chassis Ground — On the driver's side frame rail, accessible after removing the front portion of the wheel well liner. It consists of a 10mm and a 13mm bolt securing ground wires to studs.. This is a notoriously problematic ground point on the Dart. Corrosion builds up between the terminals and the chassis, creating high resistance that can cause intermittent no-start conditions and network communication codes like U0101.
• Engine Ground Strap — Connects from the passenger side of the engine to the passenger-side strut tower.. A poor engine-to-chassis ground can cause electrical noise and voltage differentials between modules, disrupting CAN bus communication.
• G211 — A ground point located at the right front of the center console.. This ground point is in the immediate vicinity of the TCM and likely serves the TCM and other nearby modules. A wiring diagram specifically calls out this ground, making it a key point to inspect.

Real Owner Repair Stories

• YouTube user 'Project Fiat' (2013 Dodge Dart 2.0L) — Intermittent no-crank, no-start condition. Car was driven to a store and would not restart.
  ❌ Tried (didn't work) Replacing the starter motor.
  ✅ What actually fixed it The problem was a bad ground connection. The fix was to access the main chassis ground point on the driver's side frame rail (behind the wheel well liner), remove the 10mm and 13mm nuts, and thoroughly clean the corrosion from the wire terminals and the chassis studs with a wire brush. After reassembly, the car started and ran correctly.
• Reddit user on r/dodgedart (2013 Dodge Dart Limited 1.4L Turbo with DDCT, 138k miles) — Car would not hold a gear, gear position indicator blinking, 'Service Trans' message on dash, car would shift itself to neutral. Codes P1CC0, P1CC2 were present.
  ❌ Tried (didn't work) Took to a Dodge dealer who diagnosed a bad hydraulic pump ($800), which did not fix it., Dealer then quoted a new transmission for $5,000., Took to a second independent shop who also quoted a new transmission for $5,000-$7,000.
  ✅ What actually fixed it After 3 years of being inoperable, the owner replaced the 'Smart Drive Unit' (the hydraulic actuator unit for the DDCT) with a used part costing $150-$300. This immediately resolved all symptoms and made the car drivable again.
• Reddit user on r/dodgedart (2013 Dodge Dart Rallye 2.0L) — Flickering gauges and intermittent power loss after replacing the main battery ground cable.
  ❌ Tried (didn't work) Using a standard aftermarket battery cable from AutoZone.
  ✅ What actually fixed it The issue was caused by the aftermarket cable missing a 'midway grounding point' that the OEM cable has. The OEM cable grounds in multiple locations. The fix was to source the correct OEM-style cable that connects to all required chassis ground points.
• Owner Report (NHTSA ODI #11663394) — An owner reported that when the stability control light comes on, the vehicle feels like it pops into neutral, jarring the vehicle. This event triggers code U0101 in the PCM, ABS, ESM, BCM, IPC, and RFH modules.

OEM Part Supersession History

• 68033642AB, 68192976AB, and others → 68210293AA — Updates to improve reliability and address the circuit board stress issue identified in recall 15V-542.
  Heads up: When replacing the TCM, especially for the recall, the mounting bracket must also be replaced with the updated part (CBCGR422AA) to prevent stress on the new module.

Model Year Variations Within This Range

• 2013-2015: Models with the 1.4L engine and DDCT are subject to NHTSA recall 15V-542 for a faulty TCM mounting bracket that can cause the TCM to fail. Later models or those with the recall performed have an updated bracket design.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Excessive Oil Consumption (2.4L Tigershark Engine) 🔴 High — Very common. Can start at any mileage. Owners report adding a quart of oil every 1,000-2,000 miles. The issue led to a class-action lawsuit. (Ref: TSB 09-006-20 and 09-003-23 detail an official oil consumption test. A failed test may result in engine replacement under warranty.)
• Manual Transmission Clutch Failure 🔴 High → Shop Transmission Assembly — Common on models with the 1.4L Turbo and C635 manual transmission. The clutch pedal may stick to the floor due to a failing master or slave cylinder, preventing shifting. (Ref: A class-action lawsuit was filed regarding this issue. FCA issued TSBs and an extended warranty to address degraded clutch hoses and replace master cylinders.)
• Uconnect 8.4" Screen Delamination 🟠 Medium — Widespread issue where the adhesive behind the touchscreen fails, causing bubbles, a 'melting' appearance, and phantom touches or unresponsiveness. (Ref: No recall, but it is a well-documented problem. Repair involves replacing the digitizer or the entire screen assembly.)
• Engine Stalling 🔴 High — Frequently reported, especially on the 2014 model year. Can be caused by low oil levels from the consumption issue, or other electrical/sensor faults.
• Faulty Thermostat (Code P0128) 🟡 Low — A common cause for the check engine light, where the thermostat fails or sticks open, preventing the engine from reaching operating temperature.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used TCM is a financially viable option only if you have access to a professional scan tool (like wiTECH or AlfaOBD) and are comfortable performing the mandatory 'Proxy Configuration Alignment' procedure. If you cannot program the module yourself, the labor cost at a dealer may negate the savings of a used part.

Donor-vehicle mileage cap: roughly under 75000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the part number is compatible or a direct supersession of your original part number.
• Obtain the VIN of the donor car to check its history for accidents or flood damage.
• Inspect the connectors for any bent pins, corrosion, or physical damage to the casing.
• Ideally, source from a vehicle that was not involved in a front-end collision.

OEM-only on this vehicle (don't cheap out):

• Transmission Control Module (TCM)

Aftermarket brands forum-validated for this vehicle:

• Cardone (Remanufactured)
• Dorman (Remanufactured)

Brands owners have reported issues with on this vehicle:

• Due to the complexity and programming requirements, unbranded, 'no-name' modules from online marketplaces are extremely high-risk and should be avoided.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0700 — This is a general transmission control system malfunction code that is frequently seen stored in the PCM alongside U0101 when the TCM has a communication failure.
• U0001 — A CAN C bus communication code that may appear if the wiring harness is chafed, shorted, or if a module like the TCM is pulling down the network.
• P0706 — Related to transmission range sensor performance; may appear if the TCM cannot communicate the correct gear position (PRNDL) to the dash.

Frequently Asked Questions