U0209 on 2010-2015 GMC Terrain: Lost Communication With Seat Heater Module Fixes

What's Unique About the 2010-2015 Gmc TERRAIN

For this generation of GMC Terrain and its platform-mate, the Chevrolet Equinox, this code is very frequently caused by a specific, documented software issue. Unlike many communication codes that point to wiring or hardware failure, GM issued Technical Service Bulletin (TSB) #PIC5954B acknowledging that an intermittent software problem is the likely culprit. This makes a software update the primary fix, rather than a component replacement. The TSB explicitly states "Do NOT replace the Heated Seat Module for this condition."

Diagnostic Flowchart

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

Symptoms You May Notice

• Driver and front passenger heated seats do not work.
• Heated seat indicator lights may not illuminate when the button is pressed.
• Indicator lights may turn on for a few seconds and then turn off automatically.

Most Likely Causes

1. Seat Heater Control Module Software Glitch 🔴 High Probability GM issued Technical Service Bulletin #PIC5954B specifically for this issue on this platform and many others, indicating a known software problem that causes loss of communication.
   How to confirm: The presence of U0209 combined with both heated seats being inoperative is the primary indicator. A temporary fix that strongly points to the software issue is to reset the module by pulling its fuse for 5 minutes. If the seats work after the reset, the software glitch is confirmed.
   Typical fix: Reprogram the K29 Seat Heating Control Module with the latest software calibration using the GM Service Programming System (SPS). The TSB specifies a labor time of 0.3 hours for this service.
   Est. part cost: $0
2. Blown Fuse for Seat Heater Module 🟡 Medium Probability
   How to confirm: Locate and inspect fuse #51 (a 25-amp fuse) in the under-hood fuse box. Some fuse diagrams may list this as F65. If the fuse is blown, there may be an underlying short circuit, but it's often the first and easiest check.
   Typical fix: Replace the blown fuse. If it blows again, further diagnosis of the wiring and heating elements is required.
   Est. part cost: $1-$5
3. Faulty Wiring or Loose Connector ⚪ Low Probability Wiring under the seat can be disturbed by items stored there or by seat movement, potentially causing damage or loose connections over time. The main connector can be accessed by moving the driver's seat all the way forward.
   How to confirm: Visually inspect the wiring harness and connectors under the driver and passenger seats for damage, corrosion, or disconnection. The main module (K29) is a black box located under the driver's seat.
   Typical fix: Repair the damaged wire or securely reconnect the connector. Some owners have success simply by disconnecting and reconnecting the main seat connector to reset the module.
   Est. part cost: $5-$50

Rare But Worth Checking

• Failed Seat Heater Control Module: While the TSB explicitly advises against replacing the module for this code, a complete hardware failure is still possible, though rare. This should only be considered after reprogramming and wiring checks have failed. If replacement is needed, the module must be programmed by a dealer.

Diagnosis Steps

1. Scan the HVAC module for trouble codes. Confirm that U0209 is present. Note that if U0209 is NOT present but seats are inoperative, a different diagnostic path is needed.
2. Check if both front heated seats are inoperative. If only one is out, the problem is likely different (e.g., a heating element).
3. Locate the fuse box under the hood and inspect fuse #51 (25A) for the heated seats. Replace if blown.
4. If the fuse is good, perform a module reset. Pull fuse #51 for at least 5 minutes and then reinstall it. Alternatively, move the driver's seat fully forward, locate the large electrical connector under the rear of the seat, and disconnect it for 5 minutes.
5. Test the heated seats again. If they work, even temporarily, it strongly confirms the software glitch described in TSB PIC5954B.
6. The permanent solution is to have a GM dealer or qualified independent shop with GM programming capabilities reprogram the K29 Seat Heater Control Module with the latest software calibration as per TSB #PIC5954B.
7. If reprogramming does not fix the issue, or if the fuse repeatedly blows, perform a detailed inspection of the wiring and connectors to the module for power, ground, and communication signals.

Parts You'll Likely Need

• Seat Heater Control Module Reprogramming — This is the official manufacturer-recommended fix to resolve the software glitch that causes the communication loss. The service takes approximately 0.3 hours of labor.
  OEM price range: $100-$200
  Aftermarket price range: N/A
• Fuse — A blown fuse will cut power to the module, causing a loss of communication. It's a simple and inexpensive first check. The correct fuse is a 25 Amp Mini Fuse.
  Trusted brands: Bussmann, Littlefuse
  OEM price range: $5-$10
  Aftermarket price range: $1-$5
• Seat Heater Control Module (OEM #13511697 (supercedes 13509457, 13593202)) — This part should only be replaced as a last resort if reprogramming and wiring checks fail, as per GM's TSB.
  Trusted brands: ACDelco (GM Genuine)
  OEM price range: $150-$250
  Aftermarket price range: $100-$180

Technical Service Bulletins (TSBs) & Recalls

• PIC5954B: States that with DTC U0209 and inoperative heated seats, the cause may be an intermittent software issue and the fix is to reprogram the K29 seat heater control module, not replace it. It specifies the labor operation code (2810715) and time (0.3 hr) for the reprogram.

Platform-Specific Known Issues

• A known software issue documented in TSB #PIC5954B is the primary cause for this code on 2010-2015 GMC Terrains, leading to inoperative heated seats.
• The issue is not isolated to the Terrain; it affects a wide range of GM vehicles from the same era that use the same K29 Seat Heating Control Module.

Mechanic-Grade Diagnostic Values

• K29 Seat Heating Control Module Power Supply Voltage — expected: 12V (Battery Voltage). Failure: Voltage below 12V or 0V indicates an open or short in the power supply circuit from fuse #51.
• K29 Seat Heating Control Module Ground Circuit Continuity — expected: Less than 10 ohms. Failure: Infinite resistance or high ohms reading indicates an open or high resistance in the ground circuit (G300).

Scan Tool Commands That Help

• GM TIS2WEB / SPS: K29 Seat Heater Control Module Reprogramming (Labor Op 2810715) — This is the final, manufacturer-specified repair after confirming U0209 is present and temporarily resetting the module via fuse pull. It updates the module's software to the latest calibration to fix the intermittent communication loss.

Wiring & Ground Locations

• K29 Seat Heating Control Module — Under the driver's front seat, secured to a mounting bracket.. This is the module that has lost communication. Physical access is needed to test power/ground pins or to replace it as a last resort.
• Fuse #51 — In the under-hood fuse box.. This 25A fuse provides the main power to the K29 module. A blown fuse will cause a loss of power and communication, setting code U0209.
• G300 — Behind the left (driver's) seat, on the floor, near the B-pillar.. This is a shared ground point that serves multiple components, including the Seat Heating Control Module. A loose or corroded G300 can cause an intermittent loss of communication.

Real Owner Repair Stories

• terrainforum.net / equinoxforum.net user experiences (Multiple 2010-2015 GMC Terrains and Chevrolet Equinoxes) — Both front heated seats suddenly stopped working. Pressing the button would either do nothing or the light would flash on for a second and turn off.
  ❌ Tried (didn't work) Replacing the heated seat switches., Replacing the K29 Seat Heater Control Module (the problem would often return)., Repeatedly replacing the #51 fuse when it wasn't blown.
  ✅ What actually fixed it A temporary fix was achieved by pulling the #51 fuse for 5+ minutes to reset the module. The permanent fix for दौड़ instances was having a GM dealer perform the K29 Seat Heater Control Module reprogram as specified in TSB PIC5954B.

OEM Part Supersession History

• 13509457 → 13593202, then 13511697 — Standard part revision and update by the manufacturer.
  Heads up: The newest part number (13511697) is the correct service replacement for all previous versions. Using an old, used module may re-introduce the original software fault. Any replacement module must be programmed.