P0267 on 2010-2015 GMC Terrain: Cylinder 3 Injector Circuit Low Causes and Fixes

What's Unique About the 2010-2015 Gmc TERRAIN

For this generation of GMC Terrain and its sibling, the Chevrolet Equinox, injector circuit codes like P0267 are frequently linked to a specific, well-documented wiring harness issue. A Technical Service Bulletin (TSB) from GM, #PIT5424, points to the engine harness being routed in a way that it can rub against a sharp metal bracket for the ECM or the cylinder head itself at the upper rear of the engine. This constant chafing can wear through the wire's insulation, causing a short to ground or an open circuit, triggering the P0267 code. 🎬 Watch: How to diagnose a fuel injector circuit malfunction. This makes a thorough harness inspection more critical on these vehicles than on many others where the injector itself is the primary suspect. Multiple owners and technicians have confirmed this failure point online.

Diagnostic Flowchart

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

Symptoms You May Notice

• Check Engine Light is on
• Engine running rough or vibrating (misfire)
• Hesitation or stumbling during acceleration
• Reduced engine power
• Poor fuel economy
• Hard starting condition
• Engine may stall at idle

Most Likely Causes

1. Engine Wiring Harness Damage 🔴 High Probability → Shop Engine Wiring Harness As noted in GM Technical Service Bulletin #PIT5424, the engine harness routing near the ECM and the upper rear of the engine makes it susceptible to chafing and damage, leading to short or open circuits. This is a widely reported failure mode for the GMC Terrain and Chevrolet Equinox.
   How to confirm: Perform a detailed visual inspection of the wiring harness leading to the fuel injectors, especially where it runs near the back of the engine and around the ECM mounting bracket. You may need to unwrap the protective loom or tape to expose the individual wires. Look for any signs of rubbing, melted plastic, or exposed copper wires. A common chafe point is on a metal bracket at the back of the cylinder head.
   Typical fix: Repair the damaged section of wire following proper procedures (soldering and heat-shrinking). Secure the harness away from the sharp edge that caused the damage using zip ties and wrap the repaired section with high-temperature, anti-abrasion tape (such as Tesa PET tape) to prevent future damage.
   Est. part cost: $5-$25
2. Faulty Cylinder 3 Fuel Injector 🟡 Medium Probability → Shop Fuel Injector The 2.4L Ecotec engine uses Gasoline Direct Injection (GDI) injectors which operate under high pressure and can fail electrically over time. While less common than the wiring issue, an internal short in the injector coil will cause this code.
   How to confirm: Using a multimeter, measure the resistance of the cylinder 3 fuel injector and compare it to another cylinder's injector. For the 2.4L GDI engine, a healthy injector should have a resistance between 1.1 and 2.0 ohms 🎬 See this quick guide on testing fuel injectors.. A reading significantly outside this range indicates a faulty injector. You can also swap the injector with one from another cylinder; if the code changes to that cylinder (e.g., P0270 for cylinder 4), the injector is bad.
   Typical fix: Replace the cylinder 3 fuel injector. It is often recommended to replace the injector seals at the same time. On GDI engines, this is a more involved job than on port-injected engines.
   Est. part cost: $50-$150
3. Damaged or Corroded Injector Connector ⚪ Low Probability
   How to confirm: Visually inspect the electrical connector at the cylinder 3 injector for bent pins, corrosion, a loose fit, or a broken locking tab. Gently wiggle the connector with the engine running to see if it affects the idle. A poor connection here can cause an intermittent low voltage signal.
   Typical fix: Clean the connector with electrical contact cleaner or replace the connector pigtail if it's damaged. Ensure it 'clicks' securely into place.
   Est. part cost: $10-$30

Rare But Worth Checking

• Faulty Engine Control Module (ECM): → Shop Engine Control Module (ECM) This is the least likely cause. The ECM's internal driver circuit for the injector can fail, but all other possibilities, especially wiring and the injector itself, should be exhaustively ruled out before considering ECM replacement. This is a last-resort diagnosis.

Diagnosis Steps

1. Scan the vehicle's computer to confirm P0267 is the active code and note any other codes.
2. Perform a thorough visual inspection of the engine wiring harness, focusing on the areas mentioned in TSB #PIT5424 (around the ECM and the back of the engine, especially near brackets).
3. Inspect the electrical connector on the cylinder 3 fuel injector for damage, corrosion, or loose pins.
4. If wiring appears intact, disconnect the cylinder 3 injector and measure its resistance with a multimeter. For the 2.4L engine, the specification is typically 1.1-2.0 ohms. Compare the reading to an adjacent injector to verify.
5. If the wiring and injector resistance seem okay, perform a 'noid light' test on the injector connector. The light should flash consistently when the engine is cranked or running, indicating the ECM is sending a signal. If it does not flash, the problem is in the wiring or the ECM.
6. If a wiring chafe is found, repair the damaged wire(s), protect the harness with anti-abrasion tape, and secure it away from any sharp edges.
7. If the wiring is confirmed to be good and the injector tests okay, but the noid light doesn't flash, the issue may be with the ECM. This step is often best left to a professional.

Parts You'll Likely Need

• Fuel Injector (OEM #12633784 (ACDelco 217-3427) for 2.4L Engine) — If the injector's internal coil has failed (shorted), it will cause a low circuit voltage condition and must be replaced.
  Trusted brands: ACDelco, Bosch, Delphi, Hitachi
  OEM price range: $90-$180
  Aftermarket price range: $50-$110
• Engine Wiring Harness Repair Supplies — Needed to fix chafed or broken wires, which is a very common cause of this code on the Terrain. Includes solder, heat-shrink tubing, and high-temp harness tape.
  Trusted brands: Tesa (PET Tape), 3M
  OEM price range: $10-$30
  Aftermarket price range: $5-$20
• Fuel Injector Connector Pigtail (OEM #ACDelco PT2160 (example, verify fitment)) — If the connector itself is damaged, corroded, or has a broken locking tab, it will need to be cut out and a new one spliced in to ensure a solid connection.
  Trusted brands: ACDelco, Dorman
  OEM price range: $25-$45
  Aftermarket price range: $10-$25

Related Codes That Often Appear With This One

• P0303 — This code means 'Cylinder 3 Misfire Detected'. It is a direct symptom of P0267, as the injector circuit fault prevents proper fueling, causing a misfire.
• P0261, P0264, P0270 — These are the 'Injector Circuit Low' codes for cylinders 1, 2, and 4. If multiple injector codes are present, it more strongly suggests a widespread wiring harness issue or a problem with the ECM's power supply or ground.
• P0641 — This code for 'Sensor Reference Voltage 'A' Circuit/Open' can appear alongside injector codes if a wiring harness issue is affecting multiple circuits that share a common power or ground source from the ECM. This is mentioned in TSB #PIT5424 and PI1067.

Technical Service Bulletins (TSBs) & Recalls

• PIT5424: Mentions hard start or Service Engine Soon light with codes including P0267, advising inspection of the engine harness routing for chafing near the ECM and rear of the engine.
• PIP4924D: Notes misfires and various injector codes including P0267, pointing towards an inspection of the fuel injector wiring harness for rub-through damage against engine components.

Platform-Specific Known Issues

• TSB #PIT5424 specifically calls out inspecting the engine harness routing near the Engine Control Module and the upper rear of the engine for damage that can cause this and other injector circuit codes.
• TSB #PIP4924D also lists P0267 among a large group of injector codes that may indicate a need to inspect the fuel injector wiring harness for rub-through or internal wire opens, particularly against the intake plenum or valve cover bolts.
• Real-world owner reports on forums for the GMC Terrain and Chevrolet Equinox frequently cite the wiring harness rubbing through on a metal bracket at the back of the cylinder head as the definitive cause for single and multiple injector circuit codes.

Mechanic-Grade Diagnostic Values

• GDI Fuel Injector Internal Resistance — expected: 1.1 to 2.0 Ohms. Failure: A reading of 0 Ohms (short), OL/infinite Ohms (open), or a value significantly different from the other injectors.
• Injector Control Circuit Harness Resistance — expected: Less than 0.5 Ohms. Failure: A reading higher than 0.5 Ohms indicates excessive resistance or a partially broken wire in the harness between the ECM and the injector connector.
• Injector Connector Voltage (Key On, Engine Off) — expected: Approximately 12.0V (+/- 0.5V). Failure: Low or no voltage on the power supply wire to the injector points to a problem in the wiring or the ignition relay circuit.

Scan Tool Commands That Help

• GM GDS2 / High-End Bidirectional Scan Tool: Fuel Injector Balance Test — Use this test when the injector's electrical resistance is normal but a flow issue is suspected. The tool commands the ECM to disable each injector sequentially and measures the corresponding drop in fuel rail pressure. A pressure drop for one cylinder that varies by more than 20% from the average of the others indicates a flow problem (clogged or faulty injector).

Wiring & Ground Locations

• G101 — Left front of the engine compartment. This is a primary ground for the Engine Control Module (ECM).. A poor connection at this ground can cause erratic behavior and incorrect voltage readings for multiple engine systems, including the injector driver circuits within the ECM. It should be inspected to ensure it is clean and tight.
• G109 — Top rear of the engine.. This ground is located in the same general area as the known harness chafe points. It provides a ground path for various engine components. A loose or corroded connection here could contribute to electrical issues in the vicinity.
• Injector #3 Control Wires — In the engine harness between the ECM and the #3 fuel injector on the fuel rail.. The P0267 code is set based on the voltage detected on this specific circuit. The two wires (power and control) are the primary focus for finding shorts, opens, or high resistance.