C0775 on 2015-2022 Chevrolet Express 2500: TPMS Relearn Failure Causes and Fixes

What's Unique About the 2015-2022 Chevrolet EXPRESS 2500

On the Express van and its platform-mate, the GMC Savana, the Tire Pressure Monitoring System (TPMS) is integrated with the Remote Control Door Lock Receiver (RCDLR). This single module processes signals from both your key fobs and your tire pressure sensors. This integration is why a seemingly simple tire issue can sometimes be linked to the remote entry system, and why a faulty RCDLR module or its antenna connection can trigger TPMS codes, as noted in GM technical bulletins.

Diagnostic Flowchart

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

Symptoms You May Notice

• "Service Tire Monitor System" message on the Driver Information Center (DIC).
• The TPMS warning light flashes for approximately one minute after starting the vehicle, then stays on solid.
• Inability to see individual tire pressure readings on the DIC (may show dashes '--' instead of pressure values).
• The TPMS light does not turn off after adjusting tire pressures.
• Tire pressure readings on the DIC do not match the actual positions of the tires after a rotation.

Most Likely Causes

1. Failed or Incomplete TPMS Relearn Procedure 🔴 High Probability This is the direct trigger for the code. A relearn is required after tire rotations, sensor replacement, or sometimes after a battery disconnect. The procedure can be interrupted if it times out (typically 5 minutes total), a sensor doesn't respond, or the wrong method is used.
   How to confirm: Attempt the TPMS relearn procedure as described in the owner's manual or the steps below. If the procedure 🎬 Watch: Step-by-step TPMS and tire position relearn tutorial completes successfully (indicated by a double horn chirp) and the code clears, this was the cause.
   Typical fix: Perform the TPMS relearn procedure correctly using a dedicated TPMS activation tool (like the EL-50448). This syncs the sensors' unique IDs to their positions on the vehicle.
   Est. part cost: $0-$25 (if a basic relearn tool is purchased)
2. Dead or Failing TPMS Sensor Battery 🔴 High Probability TPMS sensors use internal, non-replaceable batteries with a lifespan of 5-10 years. Vehicles in this year range are reaching the age where battery failure is common, preventing the sensor from transmitting its signal during the relearn process.
   How to confirm: During the relearn procedure, if the horn fails to chirp at one specific wheel while others succeed, that sensor is the primary suspect. A professional TPMS diagnostic tool can directly read the battery status of each sensor to confirm.
   Typical fix: Replace the faulty TPMS sensor. The tire must be dismounted from the wheel to access it. It is often recommended to replace all four sensors if they are original and over 7 years old to avoid future failures.
   Est. part cost: $30-$80 per sensor
3. Faulty Remote Control Door Lock Receiver (RCDLR) ⚪ Low Probability This module processes signals from both the TPMS sensors and key fobs. Internal failure can disrupt communication, preventing a successful relearn. This is a known issue on many GM vehicles of this era.
   How to confirm: If all TPMS sensors are confirmed to be good but none will learn, and you are also experiencing intermittent issues with your key fobs ('No Remote Detected' message, poor range), the RCDLR is the likely suspect. Advanced diagnostics with a tool like a GDS2 can confirm if the module is unresponsive.
   Typical fix: Replace the Remote Control Door Lock Receiver. The new module must be programmed to the vehicle and the key fobs must be relearned to it.
   Est. part cost: $70-$150

Rare But Worth Checking

• Incorrect or Damaged TPMS Sensor: If a sensor was recently replaced, it might be the wrong frequency (North American GM vehicles use 315 MHz, while European models often use 433 MHz) or a cheap aftermarket sensor that is incompatible. Even if the frequency is correct, the data modulation (ASK vs. FSK) can differ between sensor generations, causing incompatibility. It could also have been damaged during tire installation. This will prevent the relearn procedure from completing.
• RCDLR Antenna Connection Issue: According to GM TSB 16-NA-061, the RCDLR uses a coax cable connected to an antenna. A poor or disconnected connection at the module, amplifier, or antenna can cause intermittent loss of signal from the TPMS sensors (especially those furthest away) and poor key fob range, leading to C0775.
• Radio Frequency Interference (RFI): As detailed in GM TSB #PIC5650M, aftermarket electronic devices like LED lights, cell phone chargers, or even toll passes can emit radio frequencies that 'jam' the signal between the TPMS sensors and the RCDLR, preventing a successful relearn.

Diagnosis Steps

1. Verify the complaint: Confirm the TPMS light is flashing on startup and then staying solid, and a 'Service Tire Monitor System' message is present.
2. Check Tire Pressures: Manually inflate all tires to the pressure specified on the driver's door jamb sticker. This will not fix the C0775 code but is a necessary first step and good practice.
3. Attempt TPMS Relearn Procedure: Put the vehicle into the TPMS learn mode. This can be done via the Driver Information Center (DIC) menu by navigating to the tire pressure display and holding the set/reset button. Alternatively, with the ignition on (engine off), press and hold the lock and unlock buttons on the key fob simultaneously until the horn chirps twice.
4. Activate Sensors: Starting with the driver's front tire, use a TPMS relearn tool (such as an EL-50448) by pointing it at the tire sidewall near the valve stem and pressing the button. The horn will chirp once the sensor is learned. Proceed in order: Left Front, Right Front, Right Rear, Left Rear. The turn signal of the active corner will illuminate to guide you.
5. Identify Failing Sensor: If the horn does not chirp at a specific wheel but does at others, that sensor is likely faulty (dead battery or internal failure). A TPMS tool can confirm this by attempting to read the sensor's data (ID, pressure, battery status).
6. Replace Faulty Components: If a sensor is identified as bad, it must be replaced. This requires dismounting the tire. If all sensors fail to learn, proceed to the next step.
7. Re-run Relearn Procedure: After replacing any necessary parts, perform the relearn procedure again. A double horn chirp at the end signals a successful process.
8. Investigate RCDLR and RFI: If all sensors are known to be good but the relearn procedure consistently fails, investigate the RCDLR. Check for simultaneous key fob problems. Also, check for sources of Radio Frequency Interference (RFI) as per TSB PIC5650K, such as aftermarket chargers or LED lights, and inspect the RCDLR antenna connections per TSB 16-NA-061.

Parts You'll Likely Need

• Tire Pressure Monitoring System (TPMS) Sensor (OEM #13598771 (Supersedes: 13516164, 23445327)) — This is the most common failure point. The internal battery dies, or the sensor itself fails, preventing the relearn procedure from completing.
  Trusted brands: ACDelco (OEM), Schrader, Standard Motor Products
  OEM price range: $50-$90
  Aftermarket price range: $30-$60
• TPMS Relearn Tool (OEM #EL-50448) — While some older GM vehicles could be relearned by letting air out of the tires, this method is unreliable and slow. A dedicated activation tool like the EL-50448 is inexpensive and highly recommended by owners to complete the process quickly and correctly.
  Trusted brands: VXDAS, JDIAG, ATEQ, Autel
  OEM price range: $70-$100 (GM Branded)
  Aftermarket price range: $15-$50

Related Codes That Often Appear With This One

• C0750, C0755, C0760, C0765 — These codes indicate a fault with a specific tire pressure sensor (Left Front, Right Front, Left Rear, Right Rear, respectively). They often appear when a sensor's battery dies or the sensor fails, which then leads to a failed relearn and the C0775 code.
• B3055, B3060, B3935 — As cited in TSB #PIC5650M, these security-related codes can appear alongside C0775. This points towards a more complex electrical issue, likely a failing Remote Control Door Lock Receiver (RCDLR) or significant Radio Frequency Interference, as the RCDLR handles both TPMS and keyless entry functions.

Technical Service Bulletins (TSBs) & Recalls

• PIC5650M (and newer revisions like J/K): Mentions C0775 in a list of DTCs that can be caused by Radio Frequency Interference (RFI) from aftermarket accessories, which also causes key fob and security system issues.
• 16-NA-061: Details how a disconnected or faulty RCDLR antenna or coax cable can cause a 'Service Tire Monitor System' message, dashes for tire pressures, and poor key fob range, which are all symptoms related to code C0775.

Platform-Specific Known Issues

• The provided TSB #PIC5650M notes that C0775 can appear with security system codes (B3055, etc.) and a vehicle stall concern. This TSB primarily warns against Radio Frequency Interference (RFI) from aftermarket devices like phone chargers and LED lights, which can disrupt the RCDLR and cause these multiple, seemingly unrelated symptoms.
• As work vehicles, Express vans often have tires rotated by various shops, many of which may not perform the TPMS relearn. This causes the tire positions to be incorrect on the DIC and can lead to confusion during diagnosis, although it does not directly set the C0775 code.

Mechanic-Grade Diagnostic Values

• CAN Bus Voltage (High) — expected: 2.6V +/- 0.1V. Failure: Fluctuating voltage can indicate a polarity problem; out-of-range voltage can indicate a bad module on the network.
• CAN Bus Voltage (Low) — expected: 2.3V +/- 0.1V. Failure: Fluctuating voltage can indicate a polarity problem; out-of-range voltage can indicate a bad module on the network.
• CAN Bus Resistance — expected: 60 ohms +/- 3 ohms. Failure: Incorrect resistance indicates a problem with the terminating resistors or the wiring itself.

Scan Tool Commands That Help

• GDS2: Module Diagnostics > Remote Control Door Lock Receiver > Configuration/Reset Functions > Add/Replace Key Fobs — This function is required after replacing the RCDLR to program the existing or new key fobs to the new module.
• GDS2: Copy and Paste TPM Information — This service function, mentioned in GM service literature, should be used BEFORE replacing the RCDLR. It copies the existing sensor IDs and tire type settings from the old module, allowing you to 'paste' them into the new RCDLR, which avoids the need to perform a full sensor relearn procedure.
• GDS2: RCDLR Programming and Setup — After physically installing a new RCDLR, this SPS (Service Programming System) function is used to program the new module to the vehicle's VIN and configuration. The module will not function until this is completed.

Wiring & Ground Locations

• Remote Control Door Lock Receiver (RCDLR) — On Express and Savana vans, the RCDLR module is typically located behind the interior trim panel in the driver's side rear corner (D-pillar area). It is a small black box with two connectors.. This module is the central brain for the TPMS. All sensor signals are sent here. A failure of the module itself, its power, ground, or antenna connection will prevent the relearn procedure from completing and set a C0775.
• RCDLR Antenna — The antenna for the RCDLR is a coaxial cable that often runs from the module up the D-pillar and connects to an antenna amplifier module, which in turn connects to an antenna grid in the right rear window glass.. A disconnected or damaged antenna cable is a key failure point. If the cable is disconnected at the RCDLR, no sensors will be learned. If it's disconnected further away at the amplifier, it may only affect sensors on the opposite side of the vehicle, causing an intermittent and hard-to-diagnose relearn failure.
• DSM Fuse — Located in the instrument panel fuse block on the driver's side of the dashboard. Often labeled 'DSM' (Driver Seat Module) or similar, this 10A fuse provides power to the RCDLR.. Loss of power to the RCDLR will cause a total loss of communication, preventing both TPMS and key fob functions from working and making a relearn impossible.

Real Owner Repair Stories

• Tahoe Yukon Forum (2007 GMC Yukon XL Denali (similar platform/system)) — Could not get the TPMS relearn process to start. Even the first wheel (left front) would not learn.
  ❌ Tried (didn't work) Attempting the standard relearn procedure multiple times. Scanners did not point to a specific sensor issue initially.
  ✅ What actually fixed it The right rear wheel speed sensor was faulty. Despite the failure appearing at the first step of the relearn process (left front tire), the bad sensor on a different corner was the root cause preventing the system from working correctly.
• Chevrolet Forum (2013 Express 2500) — Intermittent 'Service Tire Pressure Monitor System' light. One sensor would drop out. After replacing the suspect sensor, the van would not enter relearn mode at all; no horn chirp when letting air out of any tire.
  ❌ Tried (didn't work) Replacing the suspect sensor (GM 13598771). Using the DIC menu to start the relearn process. Letting air out of the tires to trigger the sensors.
  ✅ What actually fixed it The user's story was unresolved in the thread, but highlights a common dead-end where a new sensor fails to be recognized and the manual (deflation) relearn method fails, pointing towards the need for a dedicated TPMS activation tool (like the EL-50448) which is more effective than the deflation method on these models.

OEM Part Supersession History

• 13516164, 23445327 → 13598771 — Standard part consolidation and potential minor revisions by the manufacturer (ACDelco/GM).
  Heads up: The latest part number, 13598771, is the correct service replacement for the specified vehicle range. However, there is a further supersession to 13540600 noted by some parts suppliers, which should also be compatible. Always verify fitment with the vehicle's VIN.

Model Year Variations Within This Range

• 2015-2022: While the fundamental system is the same, the method to initiate the relearn can vary slightly. Some Express vans allow initiating the relearn via the DIC buttons, while others may not show the option. For models where the DIC option is absent, the key fob method (pressing Lock and Unlock simultaneously) is the primary way to start the procedure.