U1440 on 2009-2018 Ram 1500: Meaning, Causes, and Fixes for 4WD Faults

What's Unique About the 2009-2018 Ram 1500

On this generation of Ram 1500, the electronic shift-on-the-fly 4WD system is sensitive to software logic errors. FCA (now Stellantis) has issued multiple Technical Service Bulletins (TSBs) acknowledging that this code, along with others, can be triggered by software glitches. Unlike many other vehicles where a 'U' code might immediately point to a failed part, on the Ram 1500, the official repair procedure often starts with a software update. This is a well-documented issue in owner forums where the dealer flash is the most commonly reported successful fix.

Generation note: The 2009-2018 model year range covers the fourth generation of the Ram 1500 (DS/DJ). The issues and fixes are generally consistent across this entire generation, with TSBs specifically addressing the problem.

Symptoms You May Notice

• "Service 4WD" light illuminated on the dash.
🎬 Watch this overview on why the Service 4WD light turns on
• 4WD system is inoperative or stuck in one mode (e.g., 2WD, 4WD High).
• Indicator lights for the 4WD selector switch may blink or not light up at all.
• Audible clicking or clunking noises from the transfer case area, especially when turning or on/off the throttle.
• A bump or harsh shift feeling from the driveline, sometimes mistaken for a transmission issue.
• Traction Control System (TCS) light may also be illuminated.

Most Likely Causes

1. Drivetrain Control Module (DTCM) Software Glitch 🔴 High Probability Manufacturer TSBs #08-083-20, #08-067-21, and #0814422 explicitly state that this code can be resolved by reprogramming the DTCM with updated software. This indicates a widespread logic issue from the factory.
   How to confirm: A dealer or a shop with a wiTECH scan tool can check the current software version against the latest available version from the manufacturer. This is the first step recommended by the TSBs.
   Typical fix: Reprogramming (flashing) the DTCM with the latest software. This is a ~3 minute process with the correct tool.
   Est. part cost: $0
2. Faulty Transfer Case Position Sensor (Range Selector) 🟡 Medium Probability This sensor tells the DTCM which gear the transfer case is in. If it provides an incorrect or erratic signal, the DTCM will log an implausibility code. TSBs often list code C1403-92 (Transfer Case Range Position Sensor-Performance) alongside U1440.
   How to confirm: Use a scan tool to monitor the sensor's live data while attempting to shift the transfer case. If the data is erratic, doesn't change, or is incorrect for the selected position, the sensor is likely faulty.
   Typical fix: Replace the transfer case position sensor. The OEM part number varies by year and transfer case; confirm with VIN. Examples include 68071234AA and 68026952AB.
   Est. part cost: $15-$40
3. Failing Transfer Case Shift Motor/Actuator ⚪ Low Probability The shift motor physically moves the transfer case gears. These motors are a known failure point. If it fails to complete a shift, the position sensor's reading will not match what the DTCM commanded, which can trigger the U1440 code. Some owners have reported fixing the issue by replacing this part, sometimes multiple times.
   How to confirm: Listen for the motor attempting to run when a 4WD mode is selected. A bidirectional scan tool can be used to command the motor to activate; failure to respond or a grinding noise indicates a problem.
   Typical fix: Replace the transfer case shift motor.
   Est. part cost: $150-$300
4. Corroded or Loose DTCM Connector ⚪ Low Probability A TSB for a later model year (22-226) indicates that a poorly seated DTCM connector can cause this exact code. A forum user on a 2016 model also reported finding corrosion on the DTCM plug, cleaning it, and resolving the issue. The module's location makes it susceptible to moisture.
   How to confirm: Visually inspect the DTCM connectors for corrosion (green or white powder), damage, or looseness. The module is typically located on the vehicle's frame rail or inside the cab on the passenger side firewall. 🎬 See how to find and remove the transfer case control module
   Typical fix: Disconnect the battery, then disconnect the DTCM connector. Clean the pins and the connector housing with electrical contact cleaner, apply dielectric grease to seal out moisture, and ensure it is fully seated and locked.
   Est. part cost: $5-$15

Rare But Worth Checking

• Damaged Wiring Harness: Rodents are known to chew on the soy-based wire insulation used in many modern vehicles, including Ram trucks. Physical damage from road debris can also occur. A visual inspection of the harness leading from the DTCM to the transfer case is a worthwhile check, especially if other electrical issues are present.
• Failed Drivetrain Control Module (DTCM): If a software update does not resolve the issue and all sensors, motors, and wiring have been confirmed to be in good working order, the module itself may have an internal fault. This is rare and should be the last item to consider replacing.

Diagnosis Steps

1. Scan for all Diagnostic Trouble Codes (DTCs) in all modules. Pay close attention to any codes stored in the DTCM, such as U0403-00 or C1403-92.
2. Check for TSBs. Contact a Ram dealer with your VIN or use an online service to determine if your DTCM has a pending software update per TSBs 08-083-20 or 08-067-21. This is the most likely fix.
3. If software is up to date, perform a thorough visual inspection of the wiring harness and connectors going to the transfer case shift motor, position sensor, and the DTCM itself. Look for corrosion, chafing, or rodent damage. A user on RamForum.com found and cleaned corrosion on the DTCM plug to fix the issue.
4. Using a capable scan tool, monitor the live data from the transfer case position sensor while an assistant attempts to shift between 2WD, 4WD High, and 4WD Low. The sensor reading should change smoothly and accurately reflect the selected position.
5. If the sensor data is good, use the scan tool's bidirectional controls to command the transfer case shift motor to activate. Listen for the motor and observe if the shift completes. If it doesn't, the motor or its power/ground circuit is suspect.
6. If the software is current and all components/wiring test good, the Drivetrain Control Module (DTCM) may be faulty.

Parts You'll Likely Need

• DTCM Software Update — This is not a physical part, but a service. It is the most common fix documented by Ram TSBs to correct logic errors in the 4WD control module.
  Trusted brands: Mopar Service (wiTECH)
  OEM price range: $100-$250
  Aftermarket price range: N/A
• Transfer Case Position Sensor (OEM #68071234AA) — This sensor is the primary source of the 'implausible' data. If it fails, it sends incorrect gear position information to the DTCM.
  Trusted brands: Mopar, Dorman, Standard Motor Products
  OEM price range: $14-$40
  Aftermarket price range: $15-$30
• Transfer Case Shift Motor (OEM #68259921AA (example, varies by transfer case model)) — If the motor fails to execute a shift commanded by the DTCM, it can lead to a mismatch between the expected and actual gear position, triggering the code. Owners report these failing and needing replacement.
  Trusted brands: Mopar, Cardone, Dorman
  OEM price range: $250-$400
  Aftermarket price range: $150-$300

Related Codes That Often Appear With This One

• U0403-00 — This code, 'Implausible Data Received From T-case', is a companion code that is almost always set along with U1440, as noted in TSBs 08-083-20 and 08-067-21.
• C1403-92 — 'Transfer Case Range Position Sensor-Performance' points specifically to the sensor that reports the transfer case's position, a common hardware cause for the U1440 fault.

Technical Service Bulletins (TSBs) & Recalls

• 08-083-20: Flash: Drivetrain Control Module (DTCM) Diagnostic and System Improvements, which lists U1440 as a primary code fixed by a software update.
• 08-067-21: A superseding bulletin that also involves reprogramming the DTCM for code U1440 and U0403-00, extending the model year coverage.
• 0814422: Another TSB that includes U1440 in a list of codes addressed by a DTCM software update.

Platform-Specific Known Issues

• Multiple TSBs (e.g., 08-083-20, 08-067-21) have been released by the manufacturer specifically to address this code with a software update, indicating it's a widespread and known software issue.
• Owner experiences on forums like RamForum.com corroborate the TSBs, with many users reporting that a dealer software flash was the ultimate fix after trying other parts.

Mechanic-Grade Diagnostic Values

• Transfer Case Position Sensor Signal Voltage — expected: Between 0.4V and 4.8V. Failure: A reading below 0.4V or above 4.8V suggests a circuit fault or failed sensor.
• DTCM 5-Volt Sensor Supply Circuit Voltage — expected: Between 4.5V and 5.5V. Failure: Voltage outside this range indicates a problem with the DTCM or wiring, not the sensor itself.
• Resistance on Sensor Signal or Ground Circuits — expected: Below 5.0 Ohms. Failure: A reading above 5.0 Ohms indicates an open or high resistance in the circuit being tested.
• Transfer Case Shift Motor Resistance — expected: 2.0 - 3.0 Ohms. Failure: A reading outside this range when testing across the motor's control wires suggests a faulty motor.

Scan Tool Commands That Help

• wiTECH (or equivalent professional scanner): DTCM Reprogramming/Flash — This is the first step recommended by multiple TSBs to fix code U1440, used to load updated module software that corrects logic errors.
• wiTECH (or equivalent professional scanner): Live Data Monitoring (T-Case Position Sensor Voltage) — Used to watch the sensor's voltage in real-time while shifting the transfer case to see if the signal is erratic, stuck, or incorrect for the selected range.
• wiTECH (or equivalent professional scanner): Actuator Tests / Bidirectional Controls — Used to command the transfer case shift motor to activate directly from the scan tool. This confirms if the motor is capable of functioning, separating a motor failure from a switch or wiring issue.

Wiring & Ground Locations

• Drivetrain Control Module (DTCM) — For 2013+ models, often located inside the cab on the passenger side, behind the carpet near the firewall. On other models, it may be on the vehicle's frame rail. A TSB for 2022 models also confirms a frame location.. This is the control module that sets code U1440. Its connector is a known point of failure due to corrosion or improper seating.
• DTCM Fuses — In the under-hood fuse box (also known as the TIPM), located on the driver's side of the engine bay.. Multiple fuses power the DTCM. For 2013-2018 models, these can include F21, F22, F57, F64, F72, F77, and F78. A blown fuse will render the entire 4WD system inoperative.
• Main Engine/Body Grounds — Key ground points are typically found on the firewall, on the core support near the battery, and from the engine block/cylinder head to the frame or body.. A poor ground connection for the DTCM or related components can cause erratic behavior and implausible voltage readings, leading to 'U' codes.

Real Owner Repair Stories

• Reddit user TimberPimp (2020 Ram 1500 (5th Gen, but issue is relevant)) — "Serv 4WD" light, DTC U1440.
  ✅ What actually fixed it Replacing the front 4WD axle actuator resolved the code and the issue. The user noted it was a fairly easy replacement.

OEM Part Supersession History

• 68026952AA → 68026952AB — Part revision or manufacturer change.
  Heads up: This part is for earlier models in the generation and may not be compatible with later years which use a different sensor.
• N/A → 68071234AA — Part for mid-to-late 4th Gen models.
  Heads up: This is one of the most common sensors for the 4th gen Ram 1500 but should always be verified with the vehicle's VIN.

Model Year Variations Within This Range

• 2009-2018: Two primary transfer cases were used: the Borg-Warner BW44-44 for trucks with the '4-Auto' option, and the BW44-45 for trucks with traditional part-time 4WD (2H, 4H, 4L). The control strategy and some parts may differ.

Diagnostic Flowchart

Other Known Issues on This Vehicle

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

• 5.7L HEMI Lifter/Camshaft Failure ('Hemi Tick') 🔴 High — Common, especially on 2009-2014 models, but can affect the entire generation. Can occur at mileages under 75,000. The issue often starts with a ticking noise and can escalate to a misfire (P0300) and catastrophic engine damage if ignored.
• Broken Exhaust Manifold Bolts 🟠 Medium — Extremely common across all years of this generation with the 5.7L Hemi. Caused by the expansion/contraction of dissimilar metals (aluminum heads, iron manifold). Results in an exhaust leak, most noticeable as a 'ticking' sound on cold starts that may disappear as the engine warms up. (Ref: No recall, but several TSBs have been issued over the years. Repair is covered under the powertrain warranty, but often becomes an out-of-pocket expense for owners.)
• Totally Integrated Power Module (TIPM) Failure 🔴 High — A well-documented issue, particularly for 2011-2012 models, but can affect others in this generation. The TIPM acts as the central electrical hub, and failure can cause a wide range of bizarre electrical problems, including a no-start condition, fuel pump issues, wipers/lights acting on their own, and random battery drain.
• Air Suspension System Faults 🟠 Medium — Common on models equipped with the optional four-corner air suspension, especially in colder climates. Issues include leaking air springs causing the truck to sag, compressor failure, and system errors displayed on the dash, disabling height adjustments.
• Cracked Dashboard 🟡 Low — Common on earlier models of this generation (approx. 2009-2013). The plastic dashboard can develop large cracks, particularly around the passenger airbag and defroster vents, due to sun exposure and material quality.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For more expensive electro-mechanical components like the Transfer Case Shift Motor, a used part from a reputable auto recycler can offer significant savings.

Donor-vehicle mileage cap: roughly under 80000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Check the electrical connector for any signs of corrosion (green/white powder) or damage.
• Inspect the housing for cracks or signs of heavy impact.
• If possible, choose a part from a vehicle in a dry, non-salt-belt region to minimize corrosion risk.

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

• DTCM Software Flash: This is a service, not a part, and can only be performed with manufacturer-licensed tools and software (Mopar wiTECH).

Aftermarket brands forum-validated for this vehicle:

• Dorman: Offers widely available replacement options for both the transfer case motor and position sensor.
• Standard Motor Products (SMP): A well-regarded brand for sensors and electrical components.

Brands owners have reported issues with on this vehicle:

• No-name, unbranded parts from online marketplaces can have poor quality control and may fail prematurely.

Real Owner Stories

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

Related OBD-II Codes

• C1403-92 — Transfer Case Range Position Sensor-Performance; frequently listed alongside U1440 in TSBs when the sensor signal is implausible.
• U0403-00 — Invalid Data Received from Transfer Case Control Module; often addressed by the same DTCM software updates (TSB 08-067-21) that fix U1440.
• P0300 — Random or Multiple Cylinder Misfire; while not directly related to the 4WD system, it is a common code on this vehicle platform when the 'Hemi Tick' leads to engine damage.
• C1403 — General Transfer Case Range Position Sensor code that may trigger if the sensor is faulty or the shift motor fails to reach the commanded position.

Frequently Asked Questions