B1935 on 2007-2014 GMC Yukon XL: Driver Heated Seat Failure Causes and Fixes

What's Unique About the 2007-2014 Gmc YUKON XL

The GMT900 platform, which includes the Yukon XL, is known for issues with heated seat components. General Motors issued a Technical Service Bulletin (TSB PIT5215A) that specifically addresses this code, pointing technicians to inspect the accessory heated seat wiring harness for damage or, more commonly, for the seat back and bottom element connectors being reversed during installation. A more frequent real-world failure is the heating element grid itself breaking from wear, or the main power connector to the under-seat module overheating and melting due to high current draw on a single pin.

Diagnostic Flowchart

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

Symptoms You May Notice

• Driver's heated seat does not work.
• Heated seat indicator light turns on for a few seconds, then shuts off.
• Heated seat indicator light stays on, but no heat is produced.
• An airbag warning light is NOT a symptom of this code on this vehicle, despite what some generic code websites may claim.
• In some cases, if the issue is a melted connector or faulty module, both heated seats may stop working.

Most Likely Causes

1. Broken Driver's Seat Heating Element 🔴 High Probability The thin grid-like wires within the heating element pad, located inside the seat cushion (bottom or back), can break from the repeated stress of entering and exiting the vehicle. The driver's side, particularly the left bolster, is most susceptible to this wear.
   How to confirm: Disconnect the heating element connector under the seat and test for continuity across the element's terminals using a multimeter. An open circuit (infinite resistance) confirms the element is broken. A typical good element should have a low resistance, often between 3.5 and 11.5 ohms depending on the specific element (back vs. bottom) and temperature. Wiggling the seat cushion while testing can help expose an intermittent break.
   Typical fix: Replace the faulty seat heating element pad (either the back or bottom cushion). This requires removing the seat's upholstery. Some owners have successfully repaired the broken wire with solder, but replacement is the more durable fix.
   Est. part cost: $70-$180
2. Damaged or Melted Heated Seat Wiring Harness Connector 🟡 Medium Probability The main power and ground pins on the connector for the heated/cooled seat module (located under the passenger seat for both sides) are known to handle high current, causing them to overheat, melt the plastic connector, and create a poor or open connection. This is a well-documented failure point across the GMT900 platform.
   How to confirm: Visually inspect the main electrical connector at the Memory Seat Module/Heated Seat Module. Look for any signs of burnt pins, melted plastic, or discoloration on the heavy-gauge power and ground wires.
   Typical fix: Replace the affected connector pigtail. A common repair involves splicing in a new connector, sometimes doubling up the power and ground wires to better distribute the electrical load, a solution noted in Ford vehicles which use a similar module. Dorman and AC Delco offer replacement 🎬 See this walkthrough on fixing a melted seat module connector. pigtails.
   Est. part cost: $25-$75 for a connector pigtail
3. Faulty Heated Seat Module ⚪ Low Probability While less common than element or wiring failure, the control module (often called the Memory Seat Module or Heated Seat Module, typically under the passenger seat) can fail internally. Power surges or internal component failure can cause it to stop functioning.
   How to confirm: After confirming the wiring and heating elements are good, the module becomes the primary suspect. A temporary fix of disconnecting the main seat connector or pulling the related fuses (e.g., RR HVAC, HVAC/ECAS) for 10 minutes can sometimes reset a 'glitched' module and restore function, pointing to a module-related issue.
   Typical fix: Replace the heated seat control module. Some replacement modules may require programming by a dealership or a properly equipped independent shop.
   Est. part cost: $100-$250

Rare But Worth Checking

• Reversed Heating Element Connectors:

Diagnosis Steps

1. Verify the symptom: Confirm the driver's heated seat is inoperative and note the behavior of the indicator light.
2. Scan for codes with a GM-capable scanner to confirm B1935 and check for other related body codes like B2425 or B2430.
3. Inspect for Melted Connector: Before extensive testing, perform a quick visual check of the main connector at the heated seat module (under the passenger seat) for any signs of melting or burnt pins, as this is a common and visible failure.
4. Perform a Module Reset: As a simple first step, locate the fuses for the heated seats (check owner's manual for 'RR HVAC' or 'HVAC/ECAS') and pull them for 10 minutes, then reinstall. Test the seat. If it now works, the issue was a temporary module glitch.
🎬 Watch: How to quickly reset your heated seat module.
5. Test the Heating Elements: Disconnect the connectors for the seat heating elements under the driver's seat. Using a multimeter set to Ohms, test the resistance. A good seat cushion element should be 3.5-11.5 ohms, and a back element 2.5-8.5 ohms (at room temp). An open loop (OL) indicates a broken element. Have someone sit and move in the seat during the test to find intermittent breaks.
6. Check for Power and Ground: If the elements test good, use a multimeter to check for pulsed voltage at the heating element connector when the switch is activated. If there is no power, the problem lies upstream in the module or wiring.
7. Inspect TSB-related wiring: If the vehicle had accessory heated seats installed, verify the longer harness lead goes to the seat back and the shorter lead to the seat bottom, per TSB PIT5215A.

Parts You'll Likely Need

• Driver Seat Cushion Heater Element Pad (OEM #23168136) — This is the most common failure point. The internal wiring grid breaks from normal wear and tear. This part number is for the lower cushion element.
  Trusted brands: ACDelco (GM Genuine), Dorman
  OEM price range: $120-$180
  Aftermarket price range: $70-$110
• Driver Seat Back Heater Element Pad (OEM #20792749) — The seat back element can also fail, though slightly less common than the cushion. This part supersedes older numbers like 15232560 and 25911156.
  Trusted brands: ACDelco (GM Genuine), Dorman
  OEM price range: $90-$150
  Aftermarket price range: $60-$100
• Heated Seat Control Module Connector (OEM #PT2785 (ACDelco)) — The main power and ground pins on the connector for the heated/cooled seat module are known to overheat and melt, causing an open circuit. The Dorman 645-500 is a common aftermarket replacement.
  Trusted brands: ACDelco, Dorman, Standard Motor Products (S-1262)
  OEM price range: $40-$60
  Aftermarket price range: $25-$40

Related Codes That Often Appear With This One

• B2425 — This code specifically points to a Driver Seat Heater Circuit fault and is often logged alongside B1935, as mentioned in TSB PIT5215A.
• B2430 — This code indicates a Passenger Seat Heater Circuit fault. If both seats fail simultaneously, you might see this code along with B1935, potentially pointing to a shared power, ground, or module issue, like the melted main connector.
• B2180 — Another related heated seat code mentioned in TSB PIT5215A, pointing to a similar fault condition.

Technical Service Bulletins (TSBs) & Recalls

• PIT5215A: Addresses conditions where the heated seat is inoperative and may set codes B1935, B2180, B2425, or B2430. The bulletin directs technicians to inspect the accessory heated seat wiring harness, specifically for reversed seat back and seat bottom heater element connectors.

Platform-Specific Known Issues

• A Technical Service Bulletin (PIT5215A) was issued for these vehicles regarding inoperative heated seats with DTC B1935. It primarily addresses the potential for reversed heater element connectors after installing an accessory kit, but confirms the group of codes related to this fault.
• A very common failure on the GMT900 platform is the main connector to the heated/cooled seat control module (located under the passenger seat) overheating and m

Mechanic-Grade Diagnostic Values

• Heated Seat Element Resistance — expected: 5.0 - 7.5 Ohms (approximate). Failure: Open circuit (infinite resistance) indicates a broken element. A reading significantly outside the expected range warrants further investigation. Some forum users consider anything over 5.5 Ohms to be faulty.
• Heated Seat Element Voltage (Duty Cycle) — expected: High: 90% duty cycle, Med: 40% duty cycle, Low: 10% duty cycle. Failure: If the module detects a fault (like an open element), it will only supply B+ voltage for 1-2 seconds before shutting down. No duty cycle reading indicates a problem upstream from the element.
• Heated Seat Thermistor Signal Voltage — expected: 4.8 - 5.2 Volts (between signal circuit and ground). Failure: Voltage outside this range indicates a fault in the thermistor or its circuit.
• Thermistor Signal Circuit Resistance to Ground — expected: Infinite resistance (Open Loop). Failure: Any continuity to ground indicates a short in the signal wire.

Hidden / Shadow Codes Worth Checking

• B1935 Sym 0E / B2425 Sym 0D: These are symptom bytes attached to the main DTC, visible on a dealer-level scanner like a Tech2 or GDS2. They provide more specific fault information (e.g., 'circuit open', 'short to ground') than the DTC alone. TSB PIT5215A lists these as known codes for this issue. (see via GM Tech2 or GDS2 scan tool.)

Scan Tool Commands That Help

• Professional Scan Tool (e.g., Snap-on, Autel, Tech2/GDS2): Heated Seat Functional Test / Output Control — This command allows a technician to bypass the control switch and module logic to directly command the heating elements ON. It is the definitive way to confirm if the heating element itself is capable of heating, isolating it from any control-side problems.

Wiring & Ground Locations

• Heated/Cooled Seat Module — Under the front PASSENGER seat, held by two 10mm nuts. This single module controls both the driver and passenger front seats.. This is the location of the most common electrical failure point for this system: the main power connector, which is known to melt.
• G303 — At the base of the driver's side 'B' pillar.. This is a primary ground point for the driver's seat and related modules. A poor connection here can cause various electrical issues, including seat functions.
• MBEC 1 Fuse — Underhood Fuse Block, located on the driver's side of the engine compartment.. This is the main 50-amp fuse that supplies power to the Mid-Bussed Electrical Center, which in turn feeds the heated seat module. If both seats are dead, this is a primary fuse to check.
• Main Power/Ground Pins (at Module) — On the large connector plugging into the heated seat module under the passenger seat. Power is typically a thick Red/White wire, and Ground is a thick Black wire.. These specific pins are prone to overheating and melting due to high current draw, causing an open or high-resistance circuit that disables the heated seats and can set B1935.

Real Owner Repair Stories

• YouTube user 'Street Riders Customs' (2010 Cadillac Escalade (GMT900 platform, identical system)) — Heated and cooled seats were not working. The connector on the module under the passenger seat was visibly burnt and melted.
  ❌ Tried (didn't work) A temporary fix of cleaning the terminals worked for a while but failed again.
  ✅ What actually fixed it The user performed a permanent fix by replacing the melted connector pigtail (Motorcraft WPT-928, which is the same as GM's). Crucially, they split the single heavy-gauge ground wire to feed two ground pins on the new connector, and did the same for the power wire, soldering the connections. This distributes the electrical load across two pins instead of one, preventing future overheating.
• Tahoe Yukon Forum user (2004 Z-71 (Similar system logic)) — Heated seats inoperative.
  ❌ Tried (didn't work) Visual inspection and basic data viewing did not pinpoint the failure.
  ✅ What actually fixed it The user used a Snap-on scan tool to run the 'functional test' for the heated seats. This bidirectional command allowed them to bypass the normal controls and activate each element individually. They discovered the driver's bottom and part of the back element were not heating up during the test, confirming the elements themselves were bad. Replacing the faulty heating pads resolved the issue.

OEM Part Supersession History

• 15232560, 25911156 → 20792749 — Part has been updated by GM over the vehicle's life.
  Heads up: The new part number is the correct service replacement for the entire generation.
• N/A (Vehicle Harness Connector) → ACDelco PT2785 / Dorman 645-500 / Motorcraft WPT-928 — This is a service pigtail to repair the common melted connector at the heated seat module.
  Heads up: The Ford Motorcraft WPT-928 is for the same module (used in many Ford vehicles) and is a widely cited, identical alternative for the GM repair.