B2425 GMC Yukon Denali: Heated Seat Malfunction Causes & Fixes (2007-2011)

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

On this generation of GMC Yukon (GMT900 platform), the heated seat elements and their wiring are a known failure point. The constant flexing and passenger weight can cause the thin wires within the heating element pad to break over time. Additionally, wiring under the seat can become chafed or stretched by the seat's movement on its tracks or by items stored under the seat. A very common design flaw on this platform is the main power connector for the heated seat module (located under the passenger seat), which is prone to overheating and melting due to undersized power and ground pins carrying high current.

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 is inoperative.
• Heated seat indicator lights on the switch may turn on for a few seconds, then turn off.
• Heated seat indicator lights may stay on, but the seat produces no heat.
• Both driver and passenger heated seats may stop working if the shared module connector is the cause.

Most Likely Causes

1. Failed Driver's Seat Bottom Heater Element 🔴 High Probability The heating grid inside the seat cushion is made of thin wires that can break from the stress of entering/exiting the vehicle and general use over time, creating an open circuit. A burn mark on the element is often visible upon removal.
   How to confirm: Disconnect the heater element connector under the seat and measure the resistance with a multimeter. A reading of 'OL' (Open Loop) or infinite resistance confirms a broken element. A good element should have a resistance between 1.5 and 5.5 Ohms. Some sources state a wider acceptable range of 3.5-11.5 ohms for the cushion element.
   Typical fix: Replace the driver's seat bottom heater element pad. This requires removing the seat upholstery, which is held on by hog rings.
   Est. part cost: $70-$150
2. Melted Connector at Heated Seat Module 🔴 High Probability On GM trucks of this era, the main power connector for the heated seat module (located under the front passenger seat) can overheat and melt. This is a well-documented design flaw where the single power and ground pins are undersized for the current draw, causing high resistance and heat.
   How to confirm: Visually inspect the large 12-pin electrical connector at the Heated Seat Module, which is located under the front passenger seat, for any signs of melting, discoloration, or burnt pins. The pink/white power wire and the black ground wire are the most common to show damage.
   Typical fix: Replace the connector pigtail. A widely-cited permanent fix involves using the replacement pigtail (Motorcraft WPT-928 is a common cross-fit) and adding jumper wires to utilize the unused redundant power and ground pins on the module, effectively splitting the load across two sets of wires 🎬 Watch: How to perform this permanent pigtail wiring fix to prevent recurrence.
   Est. part cost: $20-$40
3. Damaged or Broken Wiring Under the Seat 🟡 Medium Probability Wiring can get pinched, chafed, or stretched by the seat's movement on its tracks or by items stored under the seat. In some cases, a broken plastic lumbar support frame can create sharp edges that cut into nearby wiring harnesses.
   How to confirm: Perform a thorough visual inspection of all wiring harnesses and connectors under the driver's seat. Gently tug on wires to check for breaks inside the insulation. Pay close attention to where the harness passes near metal seat brackets. 🎬 Watch: How to find and repair broken power seat wiring
   Typical fix: Repair the broken wire(s) using a butt connector or by soldering and heat-shrinking the connection. Reroute the harness and secure it with zip ties to prevent future damage.
   Est. part cost: $5-$25

Rare But Worth Checking

• Faulty Heated Seat Control Module: This is rare and should only be considered after confirming the wiring and heater elements are in good condition. People often replace this module unnecessarily. The module is located under the front passenger seat and controls both front seats.
• Failed Driver's Seat BACK Heater Element: While the bottom cushion is more common, the backrest element can also fail and cause the B2425 code. A user on the Tahoe Yukon Forum reported chasing the code by replacing the bottom element, only to find the backrest element had severely burned through. It's important to test both elements.

Diagnosis Steps

1. Scan the vehicle's Body Control Module (BCM) with a capable scanner to confirm B2425 is present and check for any symptom bytes (like '0D' for high resistance).
2. Inspect the main connector at the heated seat module (under the passenger seat) for any signs of melting or heat damage 🎬 See how to inspect and repair melted seat module connectors, particularly on the corner pins. This is a very common failure and a quick visual check.
3. Move the driver's seat fully forward and up. Visually inspect all wiring and connectors under the driver's seat for obvious signs of damage, such as chafing, pinching, or loose connections.
4. If wiring appears intact, locate and disconnect the connectors for the driver's seat bottom and back heater elements.
5. Using a multimeter set to Ohms, measure the resistance across the two terminals of each heater element. A reading of infinite resistance (OL) indicates a broken element that needs replacement. A good cushion element should read a low resistance value (e.g., 1.5-5.5 ohms, though some sources say up to 11.5 is acceptable).
6. If both elements test good, check for power and ground at the heater element connector with the heated seat turned on to verify the integrity of the circuit from the module.
7. If power or ground is missing, trace the wiring back to the heated seat module to find the break in the circuit.

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, creating an open circuit that triggers the B2425 code. Note: Part numbers vary, confirm with VIN. Another common number is 15-4751.
  Trusted brands: ACDelco, Dorman
  OEM price range: $70-$150
  Aftermarket price range: $30-$80
• Heated Seat Module Connector Pigtail (OEM #3U2Z14S411ZMB) — If the main connector at the control module under the passenger seat has melted, this pigtail is required to repair the harness. The Ford/Motorcraft part WPT-928 is widely confirmed by owners and mechanics in videos to be a direct, robust cross-fit for this GM application.
  Trusted brands: Motorcraft, ACDelco, Dorman
  OEM price range: $20-$40
  Aftermarket price range: $15-$30
• Driver Seat Back Heater Element Pad (OEM #23466733) — Less common than the cushion, but the backrest element can also fail and cause this code. It should be tested if the cushion element is good.
  Trusted brands: ACDelco, Dorman
  OEM price range: $60-$120
  Aftermarket price range: $30-$70

Related Codes That Often Appear With This One

• B2430 — This is the equivalent code for the passenger's side heated seat. If both appear, it could point to a shared issue like a melted main connector at the control module.
• B1935 — Another code related to the driver's heated seat circuit, often for the seat back element. It is frequently logged alongside B2425 as noted in TSB PIT5215A.
• B2180 — A general heated seat system code also mentioned in TSB PIT5215A that can appear with other seat heating faults.

Technical Service Bulletins (TSBs) & Recalls

• PIT5215A: Addresses inoperative GM accessory heated seats where the seat does not heat, potentially setting code B2425 Sym 0D. It suggests inspecting the wiring harness to ensure the heater element connectors for the seat back and cushion are not reversed.

Platform-Specific Known Issues

• TSB PIT5215A notes that on vehicles with accessory heated seats installed, this code can be triggered if the seat back and seat cushion heater element connectors are reversed during installation. The bulletin advises checking that the longer wire lead goes to the seat back element and the shorter lead goes to the seat bottom element.
• A broken plastic lumbar support frame inside the driver's seat back is a known issue that can create sharp edges, which then chafe through the heated seat wiring harness, causing a short or open circuit.

Mechanic-Grade Diagnostic Values

• Seat Cushion Heater Element Resistance — expected: 2.5 - 8.5 Ohms at room temperature (20°C/68°F).. Failure: A reading of 'OL' (Open Loop) or infinite resistance indicates a broken element. A reading above 8.5 Ohms will set a high resistance code like B2425 0D.
• Seat Back Heater Element Resistance — expected: 3.5 - 11.5 Ohms at room temperature (20°C/68°F).. Failure: A reading of 'OL' (Open Loop) indicates a broken element. A reading above 11.5 Ohms indicates high resistance.
• Heated Seat Element Duty Cycle (via Scan Tool) — expected: When set to High, the duty cycle should be 90%.. Failure: If the module detects a fault, it will only supply voltage for 1-2 seconds before shutting down, resulting in no duty cycle reading.

Hidden / Shadow Codes Worth Checking

• B2425 0D: Left Seat Heater Cushion Circuit Resistance Above Threshold. This is the most common symptom code and points to an open circuit (broken element). (see via GM Tech2, GDS2, or equivalent professional scan tool.)
• B2425 0E: Left Seat Heater Cushion Circuit Resistance Below Threshold. This indicates a shorted or partially shorted heating element. (see via GM Tech2, GDS2, or equivalent professional scan tool.)
• B2425 04: Left Seat Heater Cushion Circuit Open. Set when the module does not detect a temperature change within a set time (e.g., 210 seconds). (see via GM Tech2, GDS2, or equivalent professional scan tool.)
• B2425 0B: Left Seat Heater Cushion Circuit Current Above Threshold. Indicates a short circuit drawing too much current. (see via GM Tech2, GDS2, or equivalent professional scan tool.)
• B2425 1F: Left Seat Heater Cushion Circuit Intermittent. Set when a fault is detected intermittently. (see via GM Tech2, GDS2, or equivalent professional scan tool.)

Scan Tool Commands That Help

• GM Tech2 / GDS2: Heated Seat Output Control — After verifying element resistance, a technician can use the scan tool to command the heated seat module to activate the driver's seat heater. This bypasses the switch and helps determine if the module itself is capable of sending power to the element. If the seat heats up with the scan tool command, the issue may lie in the switch or its wiring. If it doesn't, it confirms a fault in the module or the power/ground wiring to the element.

Wiring & Ground Locations

• Heated Seat Control Module — Under the front PASSENGER seat, mounted to the floor.. This module controls both front heated seats. Its main power connector is the most common point of failure due to melting.
• Connector X305 — The large 12-pin main electrical connector that plugs into the Heated Seat Control Module under the passenger seat.. This is the connector that is prone to melting. The power and ground pins are on the corners and should be inspected closely for charring or discoloration.
• G303 — A common ground point located at the base of the left (driver's side) 'B' pillar.. A poor ground connection at this location can cause various electrical issues, including intermittent or inoperative heated seats. Verifying this ground is clean and tight is a valid diagnostic step if circuit tests show high resistance on the ground side.
• SEAT CB (Circuit Breaker) — Located in the Left Instrument Panel Fuse Block, accessible by opening the driver's door and removing the side dash cover. It is often a silver metal can-style breaker, not a standard plastic fuse.. This circuit breaker protects the power feed to the heated seat module. If it trips or fails, both seats will lose power.

Real Owner Repair Stories

• YouTube video by 'Just Rob' (2010 Cadillac Escalade Platinum (GMT900 platform)) — Heated and cooled seats were not working.
  ❌ Tried (didn't work) A temporary fix of cleaning the burnt connector pins worked for a short time but the problem quickly returned.
  ✅ What actually fixed it The permanent fix was replacing the melted 12-pin connector at the heated seat module with a new pigtail (Motorcraft WPT-928). Crucially, the single factory power wire was spliced into two wires on the new pigtail, and the single factory ground wire was also spliced into two wires. This utilizes the two power and two ground terminals available on the module, distributing the electrical load and preventing the connector from overheating and melting again.

OEM Part Supersession History

• GM 88988313 (ACDelco PT2389) → Motorcraft WPT-928 — Cross-brand compatibility and robustness.
  Heads up: The Ford/Motorcraft WPT-928 is a pigtail for the same seat control module used by GM. It is widely confirmed by mechanics and owners to be a higher quality, more readily available replacement for the GM connector that is prone to melting. It comes with all 12 pins wired, facilitating the permanent fix of using redundant power/ground pins.
• 15232559 → 20792748 — Part has been updated by the manufacturer.
  Heads up: These are part numbers for the seat CUSHION heating element.
• 15232560, 25911156 → 20792749 — Part has been updated by the manufacturer.
  Heads up: These are part numbers for the seat BACK heating element.

Model Year Variations Within This Range

• 2007-2014: For vehicles equipped with cooled seats (RPO KB6), the heating function is still performed by a conventional resistance wire heating element pad, not by reversing the thermoelectric device (TED). The TED is used for cooling only in these models.