OBD-II Code U1446: Implausible Data from Heated Steering Wheel

What Does U1446 Mean?

Code U1446 means the main computer received an illogical temperature reading from the heated steering wheel sensor. The sensor data travels over a local data network (LIN bus) to a control module. Because the computer cannot trust the temperature signal, it disables the heated steering wheel to prevent overheating.

Technical definition: Implausible Heated Steering Wheel Temperature Message Received. The control module (often the Heated Seat Module) detected a fault in the temperature data from the steering wheel sensor for more than two seconds. This data passes through the Steering Column Control Module (SCCM) and relays to the Heated Seat Module (HSM) over the CAN bus.

Can I Drive With U1446?

✅Yes. This code disables the heated steering wheel but does not impact steering, braking, or engine performance. However, if the underlying cause is a faulty clockspring, it can eventually disable other steering wheel controls or the airbag, so schedule a diagnosis promptly.

Common Causes

• Corroded or Damaged Wiring Splice (SD403) (Very Common) — On 2019+ Ram trucks, a specific wiring splice (SD403) in the driver's side door sill corrodes or breaks due to moisture exposure. This single failure interrupts the communication signal from the steering wheel, triggering U1446.
• Defective Clockspring (Common) — The clockspring is a rotary electrical connector in the steering column. As it wears out from millions of rotations, the internal ribbon cable for the heated wheel sensor breaks, causing an open circuit.
• Faulty Steering Wheel Switch Assembly (Common) — The temperature sensor is built directly into the steering wheel's right-side control switch pack. If the sensor or the switch assembly fails, it sends an incorrect or missing signal.
• Incorrect Module Configuration (Less Common) — When a replacement Comfort Seat Wheel Module (CSWM) is installed on a Ram truck, it requires a specific ignition-cycling procedure to configure. If skipped, the universal module looks for features the truck lacks and sets code U1446.
• Failed Heated Seat / Comfort Control Module (Less Common) — The module controlling the heated steering wheel can malfunction internally, failing to process the signal from the steering wheel or failing to send power to the heating element.
• Pinched or Frayed Wires in Steering Column (Rare) — The wiring harness inside the steering column can become pinched or chafed during previous repairs (like an ignition switch replacement), causing a short or open circuit for the temperature sensor signal.
• Blown Fuse or Faulty Relay (Rare) — A blown fuse for the Steering Column Control Module or Heated Seat Module causes a total loss of function accompanied by communication codes.
🎬 Watch: Locate the heated steering wheel fuse on Jeep Grand Cherokees.
• Aftermarket Component Interference (Rare) — Improperly installed aftermarket remote starters or alarms can tap into and corrupt the vehicle's LIN or CAN bus, blocking the signal from the steering wheel.

Symptoms

• Heated steering wheel does not work — The heat never turns on when the button is pressed.
• Heated steering wheel turns off by itself — The indicator light turns on briefly and then goes out as the system detects the fault and enters self-preservation mode.
• Other steering wheel buttons fail — Intermittent or total failure of radio, cruise control, or phone buttons indicates a shared wiring path issue, such as a broken clockspring.
• Power Inverter or Rear Heated Seats Inoperative — On Ram trucks, a failure of the SD403 wiring splice also disables the 110V power inverter and rear heated seats.
• Warning messages on dash — A 'Service Steering Column Control Module' message may appear on the instrument cluster.

Diagnostic Flowchart

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

Common Fixes & Costs

• Repairing Corroded Wiring Splice (SD403) — Parts: $0 - $20, Labor: $150 - $300, ~1.5 hr book time (Intermediate)
• Replacing the Clockspring — Parts: $80 - $500, Labor: $150 - $300, ~1.5 hr book time (Professional)
• Replacing the Heated Steering Wheel Switch Pack — Parts: $70 - $200, Labor: $120 - $250, ~1.2 hr book time (Professional)
• Replacing the Heated Seat / Comfort Control Module — Parts: $150 - $350, Labor: $100 - $200, ~1.0 hr book time (Intermediate)
• Fuse Replacement — Parts: $1 - $10, Labor: $0 - $50, ~0.1 hr book time (Beginner)

DIY vs Professional

• Repairing Corroded Wiring Splice (SD403) 🟢 Beginner
  Tools: Trim panel removal tools, wire strippers, soldering iron, heat shrink tubing, multimeter.
• Replacing the Clockspring 🟢 Beginner
  Tools: Socket set, torque wrench, steering wheel puller, trim tools, battery wrench.
• Replacing the Heated Seat / Comfort Control Module 🟢 Beginner
  Tools: Basic hand tools (socket set, screwdrivers).
• Replacing the Heated Steering Wheel Switch Pack 🟢 Beginner
  Tools: Socket set, trim tools, small screwdrivers.

Used vs. New Parts: Buying Guide

When a used part is worth it: Used control modules or switch packs are cost-effective for older vehicles. However, never buy a used clockspring, as it is a wear item with limited remaining life.

Donor-vehicle mileage cap: roughly under 100000 miles for the part to have meaningful remaining life.

Donor quality checklist:

• Verify the donor vehicle was not involved in a flood or fire.
• Match part numbers exactly, as modules are specific to VIN and equipment levels.
• Avoid used clocksprings entirely.

Decision logic:

• If The part is a clockspring → Buy new. The risk of premature failure or airbag system incompatibility is too high.
• If The part is a control module for a vehicle >100k miles → A used module from a reputable seller is reasonable, provided it can be correctly configured for your vehicle.
• If The part is a simple switch pack → Used is acceptable, as these have lower failure rates than modules or clocksprings.

Warranty tradeoff: Used parts typically come with a 30-90 day warranty. New aftermarket parts offer 1-year warranties. New OEM parts carry a 1-2 year manufacturer warranty.

Worst-case if a used part fails: $300-600 if a used module or clockspring fails, requiring repeat labor costs plus a new part.

What Happens If You Wait — Timeline

1. Immediate: Code U1446 sets. The control module disables the heated steering wheel as a safety precaution. The indicator light flashes briefly and turns off. (MPG impact: 0%% · Added cost: $0)
2. Weeks to Months: If caused by a corroding wire splice, corrosion spreads to adjacent wires, disabling the 110V power inverter or rear heated seats. (MPG impact: 0%% · Added cost: $200 - $600)
3. Months: If caused by a failing clockspring, the internal ribbon cable degrades further. Radio, cruise control, and horn buttons fail intermittently. (MPG impact: 0%% · Added cost: $150 - $300)
4. 6+ Months: The driver's airbag circuit fails due to a severed clockspring ribbon, illuminating the airbag warning light and creating a critical safety hazard. (MPG impact: 0%% · Added cost: $600 - $1200)

Cost of Not Fixing It

• Immediate: Loss of heated steering wheel function. (Added cost: Negligible)
• Weeks to Months: If caused by a faulty clockspring, other steering wheel functions like the horn, radio controls, or the driver's airbag fail, creating a significant safety hazard. (Added cost: $0)
• Months to Years: If caused by a corroded wiring splice, corrosion spreads to adjacent wires, causing failures in the power inverter or rear heated seats. (Added cost: $200 - $600)

Diagnosis Steps

1. Check for Other Codes
   Use an OBD-II scanner to check for other Diagnostic Trouble Codes (DTCs). Communication codes like U112D or U116A indicate a broader electrical issue (like a shared splice or clockspring) rather than an isolated sensor failure.
   Tools: OBD-II Scanner (Beginner)
2. Inspect the Driver's Door Sill Wiring (SD403 Splice)
   Remove the driver's door sill trim panel and locate the main wiring harness. Inspect it for green corrosion, damage, or poorly secured connections. Wiggle the harness while an assistant tries to activate the heated wheel to identify an intermittent connection.
   Tools: Trim removal tools, flashlight (Intermediate)
3. Perform Module Configuration (If Recently Replaced)
   If the Heated Seat Module (HSM) or Comfort Seat Wheel Module (CSWM) was recently replaced, cycle the ignition to RUN for 30 seconds, OFF for 30 seconds, then back to RUN. Clear the codes.
   Tools: None (Beginner)
4. Live Data PID Monitoring
   Using a bidirectional scan tool, monitor the live data PIDs for the Heated Seat Module. Check the 'Heated Wheel Temp Sensor Voltage'. If the module receives the command but shows a stuck or default temperature value, the sensor or wiring is faulty.
   Tools: Advanced bidirectional scan tool (Advanced)
5. LIN Bus Signal Voltage Test
   Back-probe the LIN bus signal wire at the steering wheel switch connector. Using a multimeter on DC Volts, check the 'at rest' voltage (typically 7V-12V). When active, the voltage should toggle rapidly towards 0V-1V. A steady 0V or battery voltage indicates a short or open circuit.
   Tools: Digital Multimeter or Oscilloscope, Back-probe pins (Advanced)
6. Inspect Connectors Inside the Steering Column
   Disconnect the battery and wait 15 minutes to disable the airbag system. Remove the driver's airbag to access the clockspring and steering wheel switch connectors. Inspect for loose, spread, or corroded pins.
   Tools: Socket set, trim removal tools, battery terminal wrench (Professional)
7. Test the Clockspring and Sensor Circuit
   With the airbag removed, use a multimeter to check for continuity (resistance less than 5.0 ohms) through the specific clockspring wires connecting to the switch pack. Check for a short to ground by measuring resistance between the signal wire and chassis ground (should be >10k ohms).
   Tools: Digital Multimeter, Wiring diagram (Professional)
8. Test the Control Module
   If all wiring and components test good, use a bidirectional scan tool to command the heated steering wheel relay on directly. If the module receives a good signal but fails to activate the heater, replace the module.
   Tools: Advanced bidirectional scan tool (Professional)
9. Advanced Module Diagnostics & Proxy Alignment
   After replacing a module on Stellantis vehicles, perform a 'Proxy Alignment' using a dealer-level scan tool to ensure all vehicle modules recognize the new part. A flashing odometer indicates a proxy alignment is required.
   Tools: Advanced bidirectional scan tool (e.g., AlfaOBD) (Professional)

When This Code Triggers (Freeze-Frame Conditions)

• Ignition Status: RUN (The code sets when the engine is running and the heated steering wheel is requested by the driver.)
• System Voltage: 12.6 - 14.8 Volts (The fault is monitored when the vehicle's electrical system operates at normal voltage.)
• Time Active: > 2 seconds (The control module must see the implausible signal for a continuous period before logging the fault.)
• Communication Bus Status: Active (The code sets during active communication between the steering column controls and the heated seat module.)

Related Codes

• U112D — 'Lost Communication With EVIC Steering Wheel Switches'. Indicates a general communication failure with the switch pack. If seen with U1446, the fault is in a shared wiring path like the clockspring or SD403 splice.
• U116A — 'Lost Communication With Power Inverter Module'. On Ram trucks, the inverter and steering wheel controls route through the SD403 wiring splice. Seeing these codes together makes the splice the definitive suspect.
• B1EB4 / B1EB3 / B11DC — These 'ghost' codes appear alongside U1446 on Ram trucks after a Comfort Seat Wheel Module (CSWM) replacement. Perform the module configuration procedure to resolve them.
• B22A3 — 'Heated Steering Wheel Control Circuit'. Points directly to an electrical fault (open or short) in the heating element's power circuit, whereas U1446 is a communication code about the sensor's data.

Climate & Environmental Factors

• Humidity and Moisture: Water ingress from open windows or wet shoes saturates the carpet, trapping moisture in wiring channels like the driver's door sill and directly causing splice corrosion.
• Cold Climates / Road Salt: De-icing chemicals and road salt act as powerful electrolytes. When mixed with moisture, they dramatically accelerate the corrosion of exposed copper wiring and connectors.

How to Talk to a Mechanic About This Code

Say this: "I have a U1446 code on my Ram truck and the heated steering wheel isn't working. Please inspect the SD403 wiring splice in the driver's door sill for corrosion before quoting a clockspring or module. I understand this is a common failure point."

This signals you are an informed customer. It directs the shop to check the cheapest and most likely cause first, preventing unnecessary parts replacement.

Avoid saying:

• 'Just fix whatever's wrong'
• 'My heated steering wheel is broken, can you look at it?'
• 'Whatever you recommend'

Questions to ask before authorizing the repair:

• Did you inspect the SD403 splice? What did you find?
• If recommending a clockspring, did you check continuity to confirm it failed?
• If recommending a control module, have you ruled out wiring and the switch pack?
• If the module was just replaced, did you perform the manufacturer's configuration procedure?
• What is the warranty on this specific repair?

Where to Take It: Dealer vs Independent vs Chain

• Dealer: A safe but expensive choice. Best if you suspect a complex module issue or if the vehicle is under warranty.
  Best for: Vehicles under warranty, Complex module replacement requiring proprietary software (Proxy Alignment), Recalls or TSB-related work
  Downsides: Highest labor rates., Defaults to replacing whole assemblies instead of attempting wiring repairs. (Typical cost: +50% vs. baseline)
• Independent Shop: Best fit for most out-of-warranty cases. An experienced independent technician checks common, inexpensive causes first.
  Best for: Out-of-warranty vehicles., Diagnosing common pattern failures (like the Ram SD403 splice)., Wiring repairs and electrical diagnosis.
  Downsides: Diagnostic tool capabilities vary widely., May lack access to the latest manufacturer-only software for module programming. (Typical cost: +0% vs. baseline)
• Chain Shop: AVOID. This code requires nuanced electrical diagnosis. The risk of misdiagnosis and unnecessary parts replacement is significant.
  Best for: Simple, high-volume jobs like oil changes and brakes.
  Downsides: Technicians lack specialized diagnostic training for complex network issues., Business model pressures technicians to replace parts rather than perform wiring repairs. (Typical cost: -10% vs. baseline)

When to Walk Away From the Repair

This is a comfort feature. You can choose to walk away from the repair and live without a heated steering wheel based on your budget.

• Car worth $25000, fix is $250: Reasonable repair. A $250 wiring fix to restore a desirable feature is a good investment.
• Car worth $8000, fix is $800: Borderline. An $800 clockspring replacement represents 10% of the car's value. Consider if other steering wheel controls are also failing.
• Car worth $4000, fix is $800: Walk away. The cost is 20% of the car's value. It is not economically sensible unless the failing clockspring disables the airbag.

What Scan Tool You Need for This Code

Minimum: A scanner that reads manufacturer-specific Body/Network codes ('U' codes) and displays live data from the Heated Seat Module.

A basic $20 code reader only shows powertrain (P-series) codes and cannot see the U1446 code or access body modules.

Budget: Autel MaxiAP AP200 (~$60) — Pairs with your smartphone to read U-codes, access body modules, and view live data streams to see what the module receives from the switch.

Mid-range: AlfaOBD (for Stellantis) or Foxwell NT510 Elite (~$130) — AlfaOBD performs active diagnostics and the critical 'Proxy Alignment' procedure needed after module replacement. Foxwell offers deep manufacturer-specific diagnostics.

Professional: Launch X431 Series or Autel MaxiCOM Series (~$500-1200) — Provides full bidirectional control to test components, full access to all modules, and advanced functions like module configuration.

Rent vs buy: Parts store rental scanners are basic OBD-II readers and cannot diagnose a U1446 code. You must buy a capable scanner or take the vehicle to a shop.

How to Clear the Code After You Fix It

1. Reconnect the battery if it was disconnected.
2. Use an OBD-II scan tool to clear the DTC from the Heated Seat Module (HSM).
3. If a module was replaced on a Ram truck, perform the ignition-cycle configuration procedure before clearing codes.

Drive cycle (~10 minutes): Start the vehicle and activate the heated steering wheel. The system performs a self-test upon activation. If the light stays on and the wheel heats up, the repair was successful. A full drive cycle is not required.

Readiness monitors affected: None

Watch out for:

• Disconnecting the battery does not clear the code from the module's memory.
• Forgetting to perform the module configuration procedure after replacing a CSWM/HSM causes the code to persist.
• If the root cause is not fixed, the code returns immediately upon the next activation attempt.

Will This Fail Emissions / State Inspection?

No — by itself this code doesn't fail OBD inspection (but it can keep readiness monitors from setting, which causes a separate fail).

• California: This code does not cause a smog check failure. Inspections focus on powertrain (P-series) codes.
• New York: U1446 does not cause a failure of the NYS emissions inspection.
• Texas: This code does not cause a failure in Texas counties that require emissions testing.

Most Commonly Affected Vehicles

• Ram 1500 (2017-2024) — Extremely prone to a faulty wiring splice (SD403) in the driver's door sill on 2019+ models. DS models are susceptible to module configuration issues.
• Ram 2500/3500 (2019-2024) — Shares the same wiring harness design as the 1500, making it highly susceptible to the SD403 splice failure.
• Dodge Charger (2011-2023) — Prone to LIN bus communication failures between the steering wheel switches and the Steering Column Control Module (SCCM).
• Dodge Durango (2011-2024) — Shares electrical architecture with Jeep models, making it prone to clockspring and module communication faults.
• Jeep Grand Cherokee (2011-2021) — Utilizes a similar heated wheel control system. Code definition may appear as 'Electronic Control Unit ROM Malfunction'.
• Chevrolet / GMC Silverado / Sierra (2014-2024) — Known for clockspring failures that disrupt the heated steering wheel circuit. Replacement requires Steering Angle Sensor (SAS) recalibration.
• Volkswagen Golf, Tiguan (2015-2023) — Experiences failure of the steering column control module or issues with capacitive touch buttons.
• Hyundai / Kia Santa Fe, Sorento (2013-2023) — Experiences issues with the heating element shorting out or control module failures.

Manufacturer-Specific Notes

• Ram / Dodge (Stellantis): The most common cause is a specific wiring splice (SD403) in the driver's side door sill harness that fails due to corrosion. Replacing the Comfort Seat Wheel Module (CSWM) requires a specific ignition-cycling procedure to configure the part.
• Jeep (Stellantis): The code definition may read 'Electronic Control Unit ROM Malfunction,' pointing directly to an internal failure of a control module requiring replacement.
• Ford: The heated steering wheel is controlled by the SECM (inside the steering wheel) on vehicles with adaptive steering, or a separate HSWM on standard vehicles. Diagnosis requires checking LIN bus communication.
• General Motors (Chevrolet / GMC): Clockspring failures are a common cause. After replacement, a Steering Angle Sensor (SAS) recalibration is required using a scan tool to ensure proper stability control function.

Real Owner Stories

2019 Ram 1500 - The Classic Splice Failure

The heated steering wheel turned on for a few seconds then shut off. Other steering wheel controls worked intermittently in damp weather.

Outcome: Found the SD403 wiring splice green with corrosion. The owner cut out the corroded section, soldered the wires, and sealed the repair with heat-shrink tubing for under $10. All functions were restored.

Lesson: On 2019+ Ram trucks, always inspect the SD403 splice in the driver's door sill before replacing expensive parts like the clockspring.

2017 Ram 1500 - A Long Misdiagnosis Saga

Heated steering wheel immediately turned back off after activation.

Outcome: The issue was ultimately fixed by the second clockspring replacement, proving the first replacement part was either defective or installed incorrectly.

Lesson: Misdiagnosis is common with shared wiring. If multiple steering wheel functions fail, the clockspring is a strong suspect, but aftermarket or poorly installed replacements can fail immediately.

Ram 1500 DS Model - The Post-Repair Ghost Code

A U1446 code appeared immediately after replacing the Comfort Seat Wheel Module (CSWM), even though the truck did not have a heated steering wheel.

Outcome: The fix required a simple ignition-cycle procedure: turn the ignition to RUN for 30 seconds, OFF for 30 seconds, then back to RUN. This allowed the universal module to learn the vehicle's actual configuration.

Lesson: If U1446 appears right after a module replacement, perform the manufacturer's specified configuration procedure before condemning the new part.

How to Prevent This Code From Triggering

• Keep Driver's Door Sill and Footwell Dry (Regularly) — Prevents moisture from wicking into the main wiring harness, stopping the corrosion that causes the common SD403 splice failure.
• Apply Dielectric Grease to Connectors (During any related repair) — Creates a moisture-proof barrier on connector pins, preventing future corrosion at common failure points.
• Use Weatherproof Splice Connectors for Repairs (During any wiring repair) — Adhesive-lined heat-shrink tubing creates a durable seal against water intrusion, preventing repeat splice failures.
• Tape the Clockspring During Steering Column Service (During any steering column repair) — Securing the clockspring prevents it from rotating freely when the steering wheel is removed. An uncentered clockspring breaks immediately upon turning the wheel.

Frequently Asked Questions

Can I still drive my car with a U1446 code?

Yes, it is safe to drive. This code only affects the heated steering wheel, which is a comfort feature and does not interfere with your ability to steer or brake.

Why did my heated steering wheel button light up for a second and then turn off?

The control module performs a self-test when you request heat. It detects the implausible data from the sensor immediately and shuts the system down to prevent overheating.

Is fixing a U1446 code a DIY job?

Checking fuses and inspecting door sill wiring can be done at home. However, replacing components inside the steering column requires removing the driver's airbag. Professional service is strongly recommended due to severe safety risks.

I just replaced the control module and the code appeared. Is the new part bad?

Not necessarily. On many vehicles, the new module is a universal part and needs to be configured to your vehicle's options. This requires a simple procedure of cycling the ignition on and off in a specific pattern.

My truck doesn't have a heated steering wheel, but it's showing a U1446 code. Why?

This is a known issue on Ram trucks after replacing the universal Comfort Seat Wheel Module (CSWM). The module sets a 'ghost code' for a feature your truck lacks. Perform the manufacturer's specific ignition-cycle procedure to configure the module and clear the code.

I replaced the clockspring for a U1446 code, but the problem is still there. What did I miss?

This is a common misdiagnosis. On many Stellantis vehicles, the root cause is a corroded wiring splice (SD403) in the driver's door sill. The fault could also be in the steering wheel switch assembly itself.

Could a weak battery cause a U1446 code?

While a weak battery causes various strange electronic issues, it is rarely the direct cause of U1446. This code typically points to a specific failure in the heated steering wheel's dedicated communication circuit. Always ensure your battery is healthy before starting complex electrical diagnostics.

What is a LIN bus?

A LIN (Local Interconnect Network) bus is a simple, single-wire data network. The steering wheel switch uses it to send temperature data to the main control module, reducing the amount of wiring needed in the steering column.

My steering wheel controls and heated wheel stopped working at the same time. What's the connection?

This means the problem is in a component or wire that all of those functions share. The top suspects are the clockspring or a shared wiring harness connection, like the SD403 splice in Ram trucks.

Can a bad fuse cause code U1446?

Yes. If the Steering Column Control Module (SCCM) or Heated Seat Module (HSM) fuse blows, the module loses power and cannot communicate. Always check the relevant fuses before diving into complex diagnostics.

Key Takeaways

• Code U1446 disables the heated steering wheel due to implausible temperature sensor data, but does not affect vehicle drivability.
• On 2019+ Ram trucks, the most common cause is a corroded SD403 wiring splice in the driver's door sill, which costs under $20 in parts to repair.
• If U1446 appears immediately after replacing a Comfort Seat Wheel Module (CSWM), perform the 60-second ignition-cycle configuration procedure before buying more parts.
• Diagnosing clockspring or switch failures requires removing the driver's airbag; stop DIY and hire a professional if you lack SRS safety training.