OBD-II Code B1446: Multi-System Fault (HVAC, OnStar, Wipers)

What Does B1446 Mean?

Code B1446 is a manufacturer-specific code, meaning its definition changes completely depending on your vehicle's make. For Toyota and Lexus, it signifies a failure in the driver-side temperature blend door actuator (servo motor). For GM (Chevrolet, Cadillac), it indicates the OnStar system's backup battery has failed. For Ford, it points to a fault in the wiper park sensor circuit.

Technical definition: For Toyota/Lexus, the definition is "Air Mix Damper Control Servo Motor Circuit". This means the A/C Amplifier commanded the servo to move, but the internal position sensor's feedback did not change for 30 seconds. For GM, it is "Backup Power Source Voltage Below Threshold," meaning the Vehicle Communication Interface Module (VCIM) detected its internal battery failed. For Ford, it is "Wiper Park Sensor Circuit Failure", meaning the Body Control Module lost the wiper park position signal.

Can I Drive With B1446?

Yes, But With Caution. For Toyota/Lexus, the vehicle is 100% safe to drive as the fault is limited to climate control comfort. For GM vehicles, the car is safe to drive, but a critical safety feature is compromised: in a severe accident that disconnects the main battery, the OnStar system will NOT automatically call for help. For Ford, it disables the wiper park function, creating a severe safety hazard in poor weather.

Common Causes

• Failed Driver-Side Air Mix Servo (Toyota/Lexus) (Very Common) — This is the definitive cause on Toyota/Lexus vehicles. The small plastic gears inside the actuator strip, the internal circuit board fails, or the conductive contact strips become worn. This prevents the A/C amplifier from reading the blend door's position.
• Failed OnStar Backup Battery (GM) (Very Common) — On General Motors vehicles, the non-rechargeable lithium battery inside the OnStar/VCIM module fails after 5-10 years, triggering the code and a red OnStar light.
• Faulty Wiper Motor or Park Switch (Ford) (Common) — On Ford vehicles, the internal park switch fails to send the correct stowed-position signal to the Body Control Module (BCM).
• Damaged Wiring or Loose Connector (Less Common) — The wiring harness leading to the servo motor (Toyota/Lexus) or OnStar module (GM) is damaged, or the connector is loose, causing a loss of power or signal.
• Jammed or Obstructed Blend Door (Toyota/Lexus) (Rare) — A foreign object falls into the vents and physically jams the door. The system logs a code because the position doesn't change when commanded.
• Needs Re-Initialization or Software Update (Toyota/Lexus) (Rare) — After a battery disconnect, the climate system requires re-initialization. Lexus also issued TSBs requiring a software update for the A/C amplifier to address servo glitches.
• Faulty A/C Amplifier or BCM (Rare) — The primary control module fails. This is extremely uncommon and is only considered after ruling out all components and wiring.

Symptoms

• Wrong Temperature on Driver's Side (Toyota/Lexus) — The driver's side vents blow hot air when the A/C is on, or cold air when the heat is on. The temperature controls become completely unresponsive on the driver's side.
• Red Light on OnStar Buttons (GM) — A solid red light illuminates on the OnStar button array, indicating the emergency backup system is dead.
• Wipers Won't Park Correctly (Ford) — The wipers stop in the middle of the windshield instead of returning to their stowed position at the base of the glass.
• Clicking or Ticking Noise from Dashboard (Toyota/Lexus) — A faint but persistent clicking or grinding sound comes from behind the driver's side of the dashboard as broken gears attempt to move the blend door.

Diagnostic Flowchart

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

Common Fixes & Costs

• Replace Driver-Side Air Mix Servo Motor (Toyota/Lexus) — Parts: $150-$300 (OEM Recommended), Labor: $800-$2500, ~7.0 hr book time (Professional)
• Replace OnStar Backup Battery (GM) — Parts: $40-$95, Labor: $90-$150, ~0.8 hr book time (DIY)
• Replace Wiper Motor Assembly (Ford) — Parts: $70-$200, Labor: $100-$250, ~1.5 hr book time (Intermediate)
• Re-Initialize HVAC System (Toyota/Lexus) — Parts: $0, Labor: $0-$150, ~1.0 hr book time (DIY)
• Update A/C Amplifier Software (Toyota/Lexus) — Parts: $0, Labor: $150-$250, ~1.2 hr book time (Professional)

Used vs. New Parts: Buying Guide

When a used part is worth it: For the Ford wiper motor, a used part from a low-mileage vehicle is a cost-effective option. For the Toyota/Lexus servo motor and the GM OnStar battery, buying used is strongly discouraged.

Donor-vehicle mileage cap: roughly under 60000 miles for the part to have meaningful remaining life.

Donor quality checklist:

• For the Ford wiper motor, ensure the donor vehicle was not in a front-end collision.
• Never buy a used GM OnStar backup battery; it is a consumable item with a finite lifespan.
• Avoid used Toyota/Lexus servo motors. The labor cost is too extreme to risk installing a used part.

Decision logic:

• If The part is the Toyota/Lexus servo motor (87106-30570) → Always buy new OEM. The labor cost is too high to risk a used part failing.
• If The part is the GM OnStar backup battery (88861186) → Always buy new OEM. It is a battery with a 5-10 year life; a used part has no value.
• If The part is the Ford wiper motor and vehicle is >100K miles → A used part from a verified low-mileage donor is a reasonable choice.

Warranty tradeoff: Used parts typically have a 30-90 day warranty. New OEM parts carry a 12-month warranty.

Worst-case if a used part fails: For the Toyota/Lexus servo, a used part failure means repeating the $800-$2500 labor bill. For the GM battery or Ford motor, the cost is the repeat labor of $100-$250.

What Happens If You Wait — Timeline

1. 0-1 month: Lexus: Driver's side temperature becomes intermittently incorrect. GM: OnStar module logs internal fault; light may not be on yet. Ford: Wiper park position becomes inconsistent. (MPG impact: 0%% · Added cost: $0)
2. 1-3 months: Lexus: Temperature is permanently stuck; a faint clicking noise begins. GM: The red OnStar light illuminates and stays on. Ford: Wipers fail to park correctly more than 50% of the time. (MPG impact: 0%% · Added cost: $0)
3. 3-6 months: Lexus: The clicking noise becomes louder as stripped gears slip. GM: The internal backup battery is completely depleted. Ford: The wiper park failure is constant. (MPG impact: 0%% · Added cost: $0)
4. 6+ months: The initial fault does not cause cascading failures. The cost remains the loss of the original function. (MPG impact: 0%% · Added cost: $0)

Cost of Not Fixing It

• Immediate: Toyota/Lexus: Loss of driver-side temperature control. GM: Loss of OnStar Automatic Crash Response. Ford: Wipers fail to park correctly. (Added cost: Negligible)
• 1-6 months: No further damage to the vehicle occurs. The primary cost remains the loss of function of the affected system. (Added cost: Negligible)
• 6+ months: The issue persists indefinitely without causing additional mechanical failures. (Added cost: Negligible)

Diagnosis Steps

1. Identify Your Vehicle's System
   Confirm the meaning of B1446 for your car's manufacturer. Toyota/Lexus = HVAC issue. GM = OnStar battery issue. Ford = Wiper issue.
   Tools: None (Beginner)
2. Scan for Body (B) Codes
   Use an OBD-II scanner that reads Body (B) codes to confirm B1446 is present. Generic $20 scanners only read Powertrain (P) codes and will not see this fault.
   Tools: OBD-II Scanner (with Body/HVAC access) (Beginner)
3. Toyota/Lexus: Confirm Symptoms & Listen for Clicks
   Cycle the driver's temperature from LO to HI. Confirm the passenger side changes temperature while the driver's side does not. Turn the radio off and listen for a repetitive clicking from the driver's side dash area.
   Tools: None (Beginner)
4. GM: Check the OnStar Light
   Look at the OnStar buttons on the rearview mirror or overhead console. A solid red status light confirms the B1446 code is for a failed backup battery.
   Tools: None (Beginner)
5. Ford: Test Wiper Park Function
   Turn on your windshield wipers and then turn them off. If they stop randomly instead of returning to the bottom of the windshield, the park switch has failed.
   Tools: None (Beginner)
6. Pro Tip (Toyota/Lexus): Analyze Live Data
   Using a professional scan tool, access the HVAC live data. Monitor 'Air Mix Servo Targ Pulse (D)' and 'Air Mix Servo Actual Pulse (D)'. When you change the temperature, the 'Targ' value changes. A stuck 'Actual' value definitively condemns the servo.
   Tools: Professional Scan Tool (e.g., Techstream) (Advanced)
7. Pro Tip (GM): Check Backup Battery Voltage
   A professional scan tool reads the backup battery voltage directly. A reading below 12.3V indicates a failed battery. The code often sets with symptom byte 'B1446 03' (Voltage Below Threshold).
   Tools: Professional Scan Tool (Advanced)
8. Pro Tip (Ford): Test the Wiper Park Switch Circuit
   Backprobe the wiper motor park switch connector. The park sense signal must switch between ground (0V) and battery voltage (~12V) when the wipers reach the park position. An unchanging signal points to a failed internal switch.
   Tools: Multimeter, Wiring Diagram (Advanced)
9. Pro Tip (Toyota/Lexus): Test the Servo Motor Directly
   Bench test the removed servo. Connect 12V positive to terminal 5 and negative to terminal 4. The arm must move smoothly to 'MAX HOT'. Reverse polarity, and it must move to 'MAX COOL'. Erratic movement confirms failure.
   Tools: 12V Power Source, Jumper Wires (Advanced)
10. Pro Tip (Toyota/Lexus): Manually Check the Damper Door
    After removing the faulty servo, move the blend door lever by hand. It must move smoothly. If it requires significant force, a physical obstruction inside the HVAC case must be removed before installing a new servo.
    Tools: Basic Hand Tools (Professional)

When This Code Triggers (Freeze-Frame Conditions)

• System State (Toyota/Lexus): HVAC On (The code sets when the A/C amplifier commands the servo to move and does not see the expected position change for 30 seconds.)
• System State (GM): Ignition ON/Self-Test (The code sets when the VCIM performs a self-test of its backup battery and detects the voltage is below a predetermined threshold.)
• System State (Ford): Wipers Commanded OFF (The code sets when the wiper switch is turned off, but the BCM does not receive a valid 'park' signal from the wiper motor's internal switch.)
• Ignition Voltage: 11.5V - 14.5V (The fault logs under normal vehicle operating voltage; it is not caused by a low main battery.)

Related Codes

• B1441 — The identical fault to the Toyota/Lexus HVAC issue, but for the passenger side air mix servo.
• B1447 — On GM vehicles, this code for 'Backup Power Source Open Circuit' appears with B1446 and confirms the OnStar battery is completely dead.
• B1443 — For Toyota/Lexus, this points to a fault in the Air Outlet (Mode) Damper Servo. The symptom is air coming from the wrong vents, not at the wrong temperature.
• B1453 — Another Toyota/Lexus HVAC code for the 'Driver Side Air Outlet Damper COOL Control Servo'. It appears alongside B1446, indicating a wider harness issue.

Climate & Environmental Factors

• Extreme Heat: For Toyota/Lexus, prolonged high interior temperatures accelerate the degradation of the plastic gears and electronic components within the servo motor. For GM, sustained exposure to high heat shortens the life of the lithium OnStar backup battery.
• Extreme Cold: For Toyota/Lexus, cold temperatures make old, brittle plastic gears inside the servo motor susceptible to cracking. For GM, extreme cold reduces the output of the aging lithium backup battery, pushing its voltage below the threshold.
• Humidity: For Ford vehicles, high humidity or water ingress into the wiper motor's electrical connector causes corrosion. This disrupts the park sensor signal and triggers code B1446.

How to Talk to a Mechanic About This Code

Say this: "{'toyota_lexus': "I have a B1446 code and the driver's side is blowing hot air. I'd like a diagnostic to confirm a failed air mix servo. Please check live data for the 'Actual' vs 'Target' pulse before quoting a dashboard removal.", 'gm': 'I have a B1446 code and a red OnStar light. I need a quote to replace the OnStar backup battery, part number 88861186.', 'ford': "My wipers aren't parking correctly and I have a B1446 code. I'd like a diagnostic on the wiper motor park sensor circuit."}"

This language shows you understand the specific meaning of the code for your vehicle. It focuses the technician on the most likely cause, preventing them from starting a broad, expensive diagnostic process.

Avoid saying:

• 'My A/C is broken.' (Leads to an expensive A/C refrigerant system check instead of a targeted servo diagnosis).
• 'My OnStar doesn't work.' (Leads to a diagnostic of the entire telematics system instead of the known battery issue).
• 'My check engine light is on.' (B1446 is a Body code, so the check engine light is usually off. This statement makes you sound uninformed).

Questions to ask before authorizing the repair:

• For Lexus/Toyota: Did you confirm with a scan tool that the servo's 'Actual Pulse' is not responding to the 'Target Pulse'? Is the initialization procedure included in the labor quote?
• For GM: Can you confirm you will let the Retained Accessory Power (RAP) fully time out before disconnecting the old battery?
• For Ford: Does the quote include replacing the entire wiper motor assembly, or just the park switch?

Where to Take It: Dealer vs Independent vs Chain

• Dealer: Recommended for Lexus/Toyota owners to first check for warranty/goodwill coverage. Otherwise, an independent is better value.
  Best for: Lexus/Toyota vehicles that might still be covered by the Customer Support Program (20LE01) or a TSB., Performing the A/C Amplifier software update mentioned in Lexus TSBs.
  Downsides: Highest labor rate, especially for the dashboard-out Lexus/Toyota repair., Unwilling to install customer-supplied parts. (Typical cost: +50% vs. baseline)
• Independent Shop: Best overall fit for most B1446 repairs, especially for the GM and Ford issues. For the Lexus repair, choose a reputable independent specialist to save significantly on labor.
  Best for: Out-of-warranty Lexus/Toyota vehicles needing the servo replacement; labor rates are much lower., The straightforward GM OnStar battery swap or the Ford wiper motor replacement.
  Downsides: Quality varies; ensure the shop has experience with extensive dashboard work if you have a Lexus/Toyota. (Typical cost: +0% vs. baseline)
• Chain Shop: AVOID for Lexus/Toyota and Ford diagnosis. Acceptable only for the simple GM battery swap if you provide the part and specific instructions.
  Best for: Possibly the simple GM OnStar battery replacement if you cannot DIY.
  Downsides: High risk of misdiagnosis due to the manufacturer-specific nature of the code., Technicians lack the experience for the complex Lexus dashboard removal. (Typical cost: -10% vs. baseline)

When to Walk Away From the Repair

If the estimated repair cost exceeds 40% of the car's private-party value, and the symptom is tolerable, consider selling the vehicle.

• Car worth $15000, fix is $2500: Fix it. The repair for a 2015 Lexus GS350 is expensive, but well below the 40% threshold of its value.
• Car worth $5000, fix is $150: Fix it. The OnStar battery replacement for a 2013 Chevy Equinox is a minor cost relative to the car's value.
• Car worth $4000, fix is $2500: Walk away. The HVAC repair cost is over 60% of the vehicle's value. It is not economical.

What Scan Tool You Need for This Code

Minimum: A scanner that reads manufacturer-specific Body (B) codes. A basic engine-only (P-code) reader will NOT see code B1446.

A $20 scanner from a parts store shows 'No Codes' because it cannot access the Body Control Module (BCM) or HVAC module where this fault is stored.

Budget: iCarsoft series (e.g., TYT V1.0 for Toyota/Lexus, GM V1.0 for GM) (~$90) — Reads and clears B-codes from specific manufacturer modules. Views basic live data.

Mid-range: Launch Creader Elite for Toyota/Lexus or GM (~$160) — Offers deep OE-level diagnostics. For Lexus, it views 'Target Pulse' vs 'Actual Pulse' live data to confirm servo failure and performs the required 'Servo Motor Initialization'. For GM, it reads the specific symptom byte to confirm battery failure.

Professional: Autel MaxiCOM MK808 (~$500-1200) — Full bidirectional control for all makes. Performs HVAC initializations, OnStar module diagnostics, and wiper motor tests.

Rent vs buy: Most auto parts stores do NOT rent scanners capable of reading manufacturer-specific Body codes. Buying a mid-range scanner is a wise investment that pays for itself by avoiding a single diagnostic fee.

How to Clear the Code After You Fix It

1. For Toyota/Lexus, a 'Servo Motor Initialization' using a professional scan tool is mandatory after servo replacement.
2. For GM, the code clears itself after the new backup battery is installed and the vehicle is started.
3. For all makes, use an OBD-II scanner capable of reading 'B' (Body) codes to clear the fault from the module's memory.

Drive cycle (~5 minutes): For Toyota/Lexus, cycle the ignition and operate the climate controls through all temperature ranges. For GM, cycle the ignition. For Ford, cycle the wipers on and off to confirm they park correctly.

Readiness monitors affected: None

Watch out for:

• Forgetting to perform the servo initialization on a Toyota/Lexus causes the new part to fail immediately.
• On GM vehicles, failing to let Retained Accessory Power (RAP) time out before disconnecting the old OnStar battery instantly drains and destroys the new battery upon connection.
• Using a basic OBD-II scanner that only reads 'P' (Powertrain) codes will not clear this 'B' (Body) code.

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 will NOT cause a failure of the California Smog Check. The test is concerned with Powertrain (P) codes, not Body (B) codes.
• New York: A B1446 code will NOT cause a failure of the NYS emissions inspection. However, if the fault is on a Ford and the wipers are non-functional, it WILL fail the separate safety inspection.
• Texas: B1446 will not cause an emissions test failure. However, driving with non-functional wipers remains illegal and unsafe.

Most Commonly Affected Vehicles

• Lexus GS 350 / GS 450h / GS F (2013-2020) — Extremely common failure. Covered under TSBs L-SB-0001-21 Rev & L-SB-0019-20. Customer Support Program 20LE01 is likely expired for most vehicles.
• Lexus IS 250 / IS 300 / IS 350 (2014-2020) — Shares the same faulty servo motor (part #87106-30570) as the GS and RC models.
• Lexus RC 200t / RC 300 / RC 350 / RC F (2015-2020) — Also known for this issue and covered by TSBs L-SB-0001-21 Rev and L-SB-0019-20.
• Chevrolet Equinox / Trax / Sonic / Camaro / Impala (2007-2017) — CRITICAL: On these GM vehicles, B1446 indicates a 'Backup Power Source' failure for the OnStar module. The fix is a new backup battery (P/N 88861186).
• Toyota Highlander / Kluger (2014-2019) — This code is seen in Toyota models sharing similar HVAC components. The repair process is identical to Lexus models.
• Lexus RX 350 / RX 450h (2010-2017) — Older generations of the RX are prone to this specific servo motor failure. May set with B1448.
• Ford F-150 / Mustang (2015-2020) — CRITICAL: On Ford vehicles, B1446 relates to a 'Wiper Park Sensor Circuit Failure'. It is completely unrelated to the climate control system.
• Chrysler/Dodge Various (2011-2021) — CRITICAL: On many Chrysler/Dodge/Jeep vehicles, B1446 indicates a 'Passenger Door Ajar Switch Circuit' failure, unrelated to HVAC.

Manufacturer-Specific Notes

• Lexus/Toyota: This is almost exclusively a Lexus/Toyota code for this specific HVAC fault. The failure is so common that Lexus issued multiple TSBs and a Customer Support Program (20LE01) to address it.
• GM (Chevrolet, Cadillac, etc.): On GM vehicles, B1446 always refers to a 'Backup Power Source' issue, meaning the internal battery for the OnStar module failed. The symptom is a red OnStar light, not an HVAC problem.
• Ford: On Ford vehicles, B1446 has a completely different meaning, related to 'Wiper Park Sensor Circuit Failure'. It has nothing to do with the HVAC system.
• Chrysler/Dodge/Jeep: On many FCA vehicles, B1446 is defined as 'Passenger Door Ajar Switch Circuit Failure'. This proves you cannot diagnose a 'B' code without knowing the manufacturer.

Real Owner Stories

2015 Lexus RC350 with HVAC failure

The driver's side AC blew hot air while the passenger side worked correctly. A clicking noise was audible from the dashboard.

What they tried:

1. A scan with Toyota Techstream confirmed code B1446.
2. Live data showed the 'Actual Pulse' for the driver's side servo was stuck.
3. An attempt to run the 'Servo Motor Initialization' utility failed.

Outcome: The owner replaced the driver-side air mix servo motor (P/N 87106-30570). The repair required removal of the driver's knee airbag assembly. After installation and a successful initialization, proper HVAC function was restored.

Lesson: On a Lexus, one-sided hot air and a clicking dash is a near-certain sign of a failed servo. Confirm with live data before starting the labor-intensive replacement. Always buy an OEM servo.

2013 Chevrolet Equinox with Red OnStar Light

The OnStar status light turned solid red, and a B1446 code was stored.

What they tried:

1. The owner confirmed the code was B1446 using a scanner capable of reading Body codes.
2. Pressing the blue OnStar button resulted in an automated message about a system issue.

Outcome: The owner purchased a new battery module (P/N 88861186) for $70. They turned the ignition off and opened the driver's door to let Retained Accessory Power (RAP) time out. They accessed the VCIM in the trunk, swapped the battery, and the red light went away. The DIY job took under 30 minutes.

Lesson: For GM vehicles, a red OnStar light and code B1446 is a simple DIY fix. Ensure all vehicle power is off before swapping the battery to avoid instantly draining the new module.

2018 Ford F-150 with Wiper Parking Issue

After having the wiper motor replaced at a dealership, the wipers would not park in the correct position.

What they tried:

1. The owner returned to the dealer but was told the behavior was normal.
2. Online research indicated the motor was not in the 'park' position before the wiper linkage was attached.

Outcome: The owner insisted on a warranty repair. The dealer acknowledged the issue and performed a proper re-installation, setting the motor to its park position first, then aligning the linkage.

Lesson: On a Ford, B1446 relates to the wiper park circuit. If this issue appears after a wiper motor replacement, it is an installation error. The motor and linkage must be correctly aligned.

How to Prevent This Code From Triggering

• Operate HVAC System Regularly (Toyota/Lexus) (Weekly) — Cycling the temperature from full hot to full cold moves the blend door actuators through their full range, preventing internal gears and contacts from seizing.
• Avoid Extreme Interior Temperatures (All Makes) (Daily Habit) — Prolonged exposure to extreme heat accelerates the degradation of plastic gears in Lexus servo motors and shortens the life of the lithium OnStar battery in GM vehicles.
• Follow Proper Battery Disconnect Procedures (GM) (During any electrical service) — Always allow Retained Accessory Power (RAP) to time out before disconnecting the main 12V battery. Failure to do so triggers the one-time-use backup battery, causing it to drain.

Frequently Asked Questions

Can I just ignore code B1446?

Yes. For Toyota/Lexus, it only affects climate comfort. For GM, you can ignore it if you do not use the OnStar emergency call feature. It will not cause further mechanical damage to the vehicle.

Why is the Lexus/Toyota repair so expensive?

The high cost is almost entirely labor. The servo motor is buried deep inside the dashboard. A technician must spend 6 to 10 hours disassembling the interior just to access the part.

Why is my OnStar light red?

A red OnStar light on a GM vehicle means the system's internal backup battery has died. The system disables itself because it cannot guarantee an emergency call in a crash where main power is lost.

Is the B1446 fix a DIY job?

Replacing the GM OnStar battery is a simple DIY repair taking under an hour. However, the Toyota/Lexus HVAC servo requires extensive dashboard disassembly and is strictly a professional-level job. The Ford wiper motor replacement is an intermediate DIY task.

My Lexus is a 2016, will the dealer fix this for free?

It is highly unlikely. Lexus Customer Support Program 20LE01 extended the warranty for 7 years or 125,000 miles. Most 2016 models have aged out of this coverage window.

My mechanic replaced the servo, but it's still not working. What's wrong?

The mechanic likely skipped the mandatory 'Servo Motor Initialization' procedure. A professional scan tool must calibrate the new motor so the system learns its physical limits.

Will a weak main car battery cause code B1446?

No. On Toyota/Lexus, this code isolates a specific servo motor circuit failure. On GM vehicles, it refers exclusively to the dedicated backup battery inside the OnStar module.

Can I just replace the broken gears inside my Lexus servo motor?

No, this is highly discouraged. The internal circuit board often fails alongside the gears. The massive labor cost to access the part makes installing anything but a complete, new OEM servo a financial gamble.

Key Takeaways

• Code B1446 has three completely different definitions: Toyota/Lexus (HVAC servo), GM (OnStar battery), and Ford (wiper park sensor).
• On Toyota and Lexus vehicles, B1446 indicates a failed driver-side air mix servo, requiring an $800 to $2,500 dashboard-out repair to restore temperature control.
• For GM owners, a solid red OnStar light confirms a dead backup battery, which is easily fixed with a $70 DIY module swap in under 30 minutes.
• Ford vehicles logging B1446 will experience wipers stopping in the middle of the windshield, requiring a $150 replacement of the wiper motor assembly.