C0267 on 2015-2019 Chevrolet Colorado: Causes, Symptoms, and Fixes

What's Unique About the 2015-2019 Chevrolet COLORADO

The second-generation Chevrolet Colorado (2015-2022) and its twin, the GMC Canyon, are known for a specific vulnerability that leads to code C0267. As documented in GM Technical Service Bulletin #PIT5499B, the EBCM connector is highly susceptible to water intrusion and terminal corrosion. This specific failure point is the most common reason owners see a 'Service Trailer Brake' message and find code C0267, often without any other direct failure of the ABS pump or module itself. The TSB also notes this can be related to the wiring conduit for ground G400.

Diagnostic Flowchart

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

Symptoms You May Notice

• "Service Trailer Brake System" message on the Driver Information Center
• ABS warning light illuminated
• Traction Control or StabiliTrak warning light illuminated
• Audible chime alerts while driving
• ABS system is non-functional
• Trailer brakes do not engage
• "Low Brake Fluid" warning light, even when the fluid level is correct

Most Likely Causes

1. Water Intrusion at EBCM Connector 🔴 High Probability As cited in TSB #PIT5499B, the design or location of the EBCM connector on this platform makes it susceptible to moisture, leading to corrosion on the terminals. The connector's seal may not be robust enough to prevent water entry over time.
   How to confirm: Visually inspect the EBCM electrical connector for signs of moisture, blue or green corrosion, or backed-out pins. The connector is located on the EBCM, which is attached to the ABS hydraulic block under the hood on the driver's side.
   Typical fix: Disconnect the battery, unplug the EBCM connector, clean the terminals on both the harness and module side with an electrical contact cleaner and a small brush (like a toothbrush). Dry thoroughly, apply dielectric grease to the connector seal to prevent future moisture intrusion, and reconnect. TSB PIT5499B notes that if corrosion is severe, the affected terminals and the EBCM itself may need replacement.
   Est. part cost: $5-$20
2. Faulty ABS Pump Motor / EBCM Assembly 🟡 Medium Probability → Shop ABS Control Module Corrosion from water intrusion can migrate from the connector pins into the module itself, causing permanent damage to the internal circuits. Internal component failure (like a cracked solder joint or seized motor) can also occur from vibration and thermal cycles.
   How to confirm: After confirming the connector is clean and dry, if the code persists, a scan tool can be used to command the ABS pump motor to activate. If it doesn't run despite receiving power and having a good ground, the motor/module is likely faulty. A multimeter can also be used to check the ABS pump motor's resistance; a typical reading should be very low, between 0.3-1.0 ohms. An infinite reading indicates an open circuit.
   Typical fix: Replace the entire EBCM and ABS pump motor assembly. This requires programming the new module to the vehicle and using a specialized scan tool to perform an automated brake bleed procedure afterward.
   Est. part cost: $300-$800
3. Damaged Wiring or Poor Ground ⚪ Low Probability
   How to confirm: Inspect the wiring harness leading to the EBCM for any signs of physical damage, chafing, or breaks. TSB #PIT5499B specifically advises inspecting the wiring conduit leading to ground G400. Check the main EBCM ground connections on the frame for tightness and corrosion. On some GM trucks, ground issues are related to splice packs (like SP105 and SP106) located under the hood which can corrode internally.
   Typical fix: Repair the damaged section of the wiring harness or clean and tighten the ground connection. In cases of a corroded splice pack, it may need to be disassembled and cleaned, or bypassed with individual ring terminals.
   Est. part cost: $10-$50

Rare But Worth Checking

• Aftermarket Speedometer Calibrator:

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner capable of reading Chassis (C) codes.
2. Visually inspect the brake fluid level. A low fluid level warning can sometimes accompany this code per TSB PIT5499B.
3. Locate the Electronic Brake Control Module (EBCM). It is found under the hood on the driver's side, attached to the ABS hydraulic block.
4. Carefully inspect the main electrical connector on the EBCM. Look for any signs of water, dirt, or blue/green corrosion. This is the most likely point of failure.
5. If corrosion is found, disconnect the vehicle's battery. Then, unplug the connector and thoroughly clean the pins and terminals on both the harness and module side using electrical contact cleaner and a small, soft brush.
6. Allow the components to dry completely. Apply a thin layer of dielectric grease to the connector seal to prevent future moisture intrusion.
7. Per TSB #PIT5499B, also inspect the wiring conduit leading to ground G400. Remove the tape from the conduit to check for trapped water.
8. Reconnect the connector and the battery. Clear the codes with the scanner and perform a test drive to see if the code returns.
9. If the code returns, check the ABS-related fuses in the underhood fuse box. There is typically a large 60-amp fuse for the ABS pump motor.
10. If fuses are good, inspect the wiring harness leading to the EBCM for any visible damage. Check the main EBCM ground connections (G400) on the frame for integrity.
11. Using a multimeter, check for battery voltage at the EBCM connector's power supply pin and check for good ground (less than 0.2 ohms resistance to chassis ground) on the ground pin.
12. If power and ground are good, check the resistance of the ABS pump motor itself through the connector pins. A reading between 0.3 and 1.0 ohms is expected. An infinite reading means the motor circuit is open.
13. If all wiring, grounds, and the connector are confirmed to be good, the EBCM/ABS pump assembly itself is likely faulty and may require replacement.

Parts You'll Likely Need

• Electrical Contact Cleaner — Needed to clean corrosion from the EBCM connector terminals, which is the most common cause.
  Trusted brands: CRC, WD-40 Specialist
  Aftermarket price range: $5-$15
• Dielectric Grease — Applied to the connector seal after cleaning to prevent future water intrusion.
  Trusted brands: Permatex, ACDelco
  Aftermarket price range: $5-$10
• Electronic Brake Control Module (EBCM) (OEM #84422426 (Verify with VIN)) — If the module itself is damaged by corrosion or has an internal failure, it will need to be replaced. This is the fix if cleaning the connector doesn't resolve the issue.
  Trusted brands: ACDelco (Genuine GM)
  OEM price range: $400-$800
  Aftermarket price range: $250-$500

Related Codes That Often Appear With This One

• C0035 — Wheel speed sensor codes can be set concurrently when the EBCM has a fault, as seen in TSB #PIT5499B.
• C0040 — Wheel speed sensor codes can be set concurrently when the EBCM has a fault, as seen in TSB #PIT5499B.
• U0121 — This code for 'Lost Communication With Anti-Lock Brake System (ABS) Control Module' often appears with C0267 when the EBCM connector is corroded, as noted in TSB #PIT5499B.
• U0415 — This code for 'Invalid Data Received From Anti-Lock Brake System Control Module' can be triggered by the same EBCM fault, as noted in TSB #PIT5499B.

Technical Service Bulletins (TSBs) & Recalls

• PIT5499B: Addresses a 'Service Trailer Brake' message and codes including C0267, pointing to potential water intrusion in the Electronic Brake Control Module connector and the G400 ground conduit. It explicitly covers the 2015-2016 Colorado and Canyon, but the issue is widely reported through 2019.
• PIT5120A: While for different GM trucks, it notes that code C0267 can be caused by aftermarket speedometer calibrators, which is a plausible, though rare, cause on the Colorado as well.

Platform-Specific Known Issues

• A known issue, documented in TSB #PIT5499B, involves water getting into the EBCM connector, causing corrosion and leading to code C0267 and a 'Service Trailer Brake' message. The TSB applies to both the Colorado and GMC Canyon.
• The same TSB also recommends inspecting the wiring conduit for ground G400 for trapped water, suggesting a potential secondary water entry point or related wiring issue.

Mechanic-Grade Diagnostic Values

• ABS Pump Motor Resistance — expected: 0.3 - 1.0 Ohms. Failure: A reading of infinity (OL) indicates an open circuit in the motor. A reading significantly outside the expected range can also indicate a problem.
• EBCM Ground Circuit Resistance — expected: 0.0 - 0.2 Ohms. Failure: A reading higher than 0.2 Ohms indicates excessive resistance in the ground circuit, which can cause the module to set codes.

Hidden / Shadow Codes Worth Checking

• C0267 71: This is a GM-specific code with a symptom byte. The '71' indicates 'Actuator Stuck'. This means the EBCM commanded the ABS pump motor to run but did not detect the expected electrical feedback signature (a change in voltage) that indicates the motor is spinning up or winding down. This points more specifically to a seized motor or an open in the power/ground or feedback circuit. (see via A professional-grade scan tool like the GM GDS2/Tech2 or high-end Autel/Snap-on scanners that can read manufacturer-specific codes and symptom bytes.)

Scan Tool Commands That Help

• GM GDS2 (or equivalent pro-level scanner): Automated Test / Functional Test — After visually inspecting the connector, a technician can use this function to command the ABS pump motor to turn on. If the motor does not run, it confirms a fault in the power, ground, or motor circuit. This is a crucial step to verify if the motor is functional before condemning the EBCM.
• GM GDS2 (or equivalent pro-level scanner): Automated Bleed — This procedure is mandatory after replacing the EBCM/ABS hydraulic unit. The scan tool cycles the internal solenoids and runs the pump motor to purge trapped air from the hydraulic block that cannot be removed with a manual bleed.
• GM GDS2 (or equivalent pro-level scanner): Module Setup / Programming — A new EBCM must be programmed with the vehicle's VIN and specific configuration using GM's Service Programming System (SPS). A used module may also need to be reprogrammed. Without this step, the module will not communicate with other vehicle systems.

Wiring & Ground Locations

• EBCM (Electronic Brake Control Module) — Under the hood on the driver's side, mounted directly to the aluminum ABS hydraulic block (Brake Pressure Modulator Valve).. This is the location of the main connector that is highly prone to water intrusion and corrosion, which is the primary cause of C0267 on this vehicle.
• G400 — The exact location is not clearly documented in public diagrams, but TSB #PIT5499B implies it is a major ground point for the EBCM, likely on the frame rail on the driver's side of the vehicle near the EBCM assembly.. TSB #PIT5499B specifically calls out inspecting the wiring conduit to this ground for trapped water, indicating it's a critical part of the EBCM circuit and a potential failure point.
• Underhood Fuse Block — On the driver's side of the engine bay, near the firewall.. This fuse block contains the main fuses for the ABS system, including a large 60A fuse for the pump motor. A blown fuse here will cause an open circuit and set code C0267.

Real Owner Repair Stories

• ColoradoFans Forum user (2016 Chevrolet Colorado) — ABS, traction control, and Stabilitrak lights all came on, along with the 'Service Trailer Brake System' message.
  ❌ Tried (didn't work) Initial diagnosis pointed towards a faulty module.
  ✅ What actually fixed it The user took the truck to the dealer, who identified corrosion in the EBCM electrical connector. They cleaned the connector, applied dielectric grease, and cleared the codes. The problem was resolved and did not return. This aligns perfectly with TSB #PIT5499B.

OEM Part Supersession History

• 84329995 → 84401914 — Part revision or supplier change. This is a common practice for GM to improve reliability or consolidate parts.
  Heads up: While 84401914 replaces 84329995, it is critical to verify the correct part number using the vehicle's VIN before ordering, as there can be variations based on specific options (e.g., automatic brake assist).