B1935 on 2007-2011 GMC Yukon Denali: Heated Seat Failure Causes and Fixes

What's Unique About the 2007-2011 Gmc YUKON DENALI

The GMT900 platform, which includes the Yukon, Tahoe, and other GM trucks, is well-known for heated seat issues. Failures are frequent due to two main reasons: the wires within the heating element pads are prone to breaking from the repeated flexing of occupants getting in and out, and the main electrical connector for the heated seat module (located under the passenger seat) can overheat and melt. While a melted connector often affects both seats, code B1935 specifically points to a fault within the driver's seat heating circuit itself.

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 side heated seat does not work.
• Heated seat indicator lights turn on for a few seconds, then turn off.
• Heated seat indicator lights stay on, but the seat produces no heat.

Most Likely Causes

1. Broken Driver's Seat Heating Element 🔴 High Probability The thin wires inside the heating element pads (both seat bottom and seat back) can fatigue and break over time from occupant weight and movement.
   How to confirm: Disconnect the heating element connector under the seat and test for resistance with a multimeter. 🎬 See this video for a step-by-step guide to troubleshooting seat heaters. A normal reading is between 3 and 12 ohms. An infinite resistance (OL) reading indicates a broken/open circuit.
   Typical fix: Replace the faulty heating element pad (either the seat cushion or seat back). This requires removing the seat's upholstery.
   Est. part cost: $50-$150
2. Damaged Wiring Harness or Connector 🟡 Medium Probability The wiring harness under the driver's seat can get chafed, pinched, or cut by the seat's movement on its tracks. Additionally, the main connector at the Heated Seat Control Module (under the front passenger seat) is a known failure point and can melt from high resistance.
   How to confirm: Visually inspect all wiring under both front seats for signs of damage, chafing, or melted plastic at the connectors. Pay close attention to the large connector on the module under the passenger seat.
   Typical fix: Repair the damaged section of wire or replace the burnt connector pigtail. 🎬 Watch: A permanent fix for burnt wiring and connector issues. If the module itself is burnt, it will also need replacement.
   Est. part cost: $10-$100
3. Faulty Heated Seat Control Module ⚪ Low Probability The module, located under the front passenger seat, can fail internally or suffer from damage to its connector pins.
   How to confirm: After confirming the heating elements and wiring are good, the module is the next likely culprit. A temporary fix can sometimes be achieved by resetting the module (disconnecting its power for 5 minutes). If the problem returns, the module is likely faulty.
   Typical fix: Replace the Heated Seat Control Module. A new module may require programming by a dealership.
   Est. part cost: $100-$250

Diagnosis Steps

1. Scan the Body Control Module (BCM) for codes. Confirm B1935 is present, and check for other related codes like B2425 or B2430.
2. Visually inspect the wiring harness connector at the Heated Seat Control Module, located under the front passenger seat. 🎬 Watch: How to inspect and repair the melted seat module connector. Look for any signs of melted plastic or burnt pins.
3. Visually inspect the wiring harnesses under the driver's seat for any signs of chafing, pinching, or breaks.
4. If wiring appears intact, disconnect the driver's seat heating element connectors. Using a multimeter, test the resistance of both the seat back and seat cushion heating elements. A reading of infinity (OL) confirms a broken element. A good element should read roughly 3-12 ohms.
5. If the elements test good, check for power and ground at the element connector when the heated seat switch is activated.
6. If there is no power at the connector but the wiring is good, the Heated Seat Control Module is the most likely cause of failure.

Parts You'll Likely Need

• Driver's Seat Heating Element Pad (OEM #20792749) — This is the most common failure point. The wires inside the pad break, creating an open circuit that triggers the code.
  Trusted brands: ACDelco, Dorman
  OEM price range: $100-$180
  Aftermarket price range: $50-$120
• Heated Seat Control Module — This module controls the entire heated seat system. Its main connector can burn out, or the module can fail internally, though this is less common than an element failure.
  Trusted brands: ACDelco
  OEM price range: $150-$250
  Aftermarket price range: $100-$200

Related Codes That Often Appear With This One

• B2425 — This is another specific code for a Driver Seat Heater Circuit fault and is often logged alongside B1935, as noted in TSB PIT5215A.
• B2430 — This code indicates a Passenger Seat Heater Circuit fault. If you see this with B1935, it strongly points to a shared problem like a melted main connector at the control module under the passenger seat.
• B2180 — Another related heated seat code mentioned in TSB PIT5215A that points to a similar fault condition.

Technical Service Bulletins (TSBs) & Recalls

• PIT5215A: Addresses inoperative heated seats where indicators may stay on but no heat is produced, potentially setting codes B1935, B2180, B2425, and/or B2430. It advises inspection of the accessory heated seat wiring harness.

Platform-Specific Known Issues

• A known issue involves the main electrical connector for the heated/cooled seat module (located under the passenger seat) overheating and melting, which can cause one or both seats to stop working.
• GM issued Technical Service Bulletin #PIT5215A which addresses this code and related symptoms, noting that heated seats may turn off after 30 seconds or not heat at all. The bulletin points to inspecting the accessory heated seat wiring harness.

Mechanic-Grade Diagnostic Values

• Driver's Seat Back Heating Element Resistance — expected: 2.5 - 8.5 ohms at room temperature. Failure: An Open Loop (OL) or infinite resistance reading. A reading significantly outside the expected range can also indicate a fault.
• Driver's Seat Cushion Heating Element Resistance — expected: 3.5 - 11.5 ohms at room temperature. Failure: An Open Loop (OL) or infinite resistance reading. Wiggling the cushion while testing can expose an intermittent break.
• Heated Seat Element Voltage (Duty Cycle) — expected: High: ~90%, Medium: ~40%, Low: ~10%. Failure: A static 0% or 100% reading, or no reading at all, when back-probing the element connector indicates a module or circuit problem.

Hidden / Shadow Codes Worth Checking

• B1935 Sym 0E: A manufacturer-specific symptom byte indicating an open circuit or, in the case of accessory heated seats, potentially reversed connectors for the seat back and cushion elements. (see via GM Tech2 or GDS2 professional scan tool.)
• B2425 Sym 0D: A symptom byte often seen with B1935, also indicating a fault in the driver's heated seat circuit. (see via GM Tech2 or GDS2 professional scan tool.)

Scan Tool Commands That Help

• GM Tech2: Output Control for Driver Heated Seat — To manually command the heated seat on/off to verify if the control module is receiving commands and to check for voltage output at the element connectors without relying on the switch. The path is: Body > Driver Seat Module > Special Functions > Output Control.

Wiring & Ground Locations

• Heated/Cooled Seat Module Connector — Under the front passenger seat, plugged into the silver control module.. This is the central connector for both front seats. The power wire (Pin A, Pink/White) and ground wire (Pin G, Black) are known to be undersized, causing them to overheat and melt the connector, which can trigger B1935.
• Memory Seat Module (MSM) Connector X1 (Green) — Under the driver's seat, connected to the seat control module.. This connector contains the specific circuits for the driver's heating elements. Resistance tests can be performed here. Pin 14 (Pink) is the shared voltage supply. Test between Pin 14 and Pin 1 (Purple) for the back heater, and between Pin 14 and Pin 11 (Light Green) for the bottom heater.
• G301 / G302 — G301 is under the left side of the passenger seat; G302 is under the right side of the passenger seat.. These are the primary ground points for components under the passenger seat, including the Heated Seat Control Module. A poor connection at these grounds can cause various electrical issues, including heated seat failure.

Real Owner Repair Stories

• Street Riders Customs / YouTube (2010 Cadillac Escalade (Same GMT900 platform and module)) — Heated and cooled seats were not working.
  ❌ Tried (didn't work) A temporary fix of cleaning the burnt terminals on the module and connector worked for about a year before failing again.
  ✅ What actually fixed it The permanent fix involved replacing the melted 12-pin connector with a new pigtail (Ford part WPT-928 is identical). The single power and ground wires were doubled up by splicing them into the two available power and two available ground pins on the new connector, distributing the electrical load to prevent future overheating.
• Reddit user in r/Silverado (2013 Chevrolet Silverado LTZ (Same GMT900 platform)) — Code B1935 was present, but the heated seats were still working correctly.
  ❌ Tried (didn't work) Visual inspection of connections and wires showed no obvious damage.
  ✅ What actually fixed it The user was advised that the resistance of a failing element can become erratic. A technician suggested testing resistance from the green Memory Seat Module connector (X1) under the driver's seat: Pin 14 to Pin 1 for the back heater, and Pin 14 to Pin 11 for the bottom heater. Pushing on the cushions during the test could reveal an intermittent open/short that sets the code even if the seat sometimes works.

OEM Part Supersession History

• 15232560, 25911156 → 20792749 — Standard part updates and revisions by the manufacturer for the driver's seat back heating element.
• ACDelco PT2389 → Motorcraft WPT-928 — The heated seat module and its 12-pin connector were also used by Ford. The Motorcraft WPT-928 pigtail is an identical and often more readily available replacement for the melted GM connector.
  Heads up: This is a cross-brand compatible part, not a direct supersession, but serves as a common replacement.