P0264 on 2010-2015 GMC Terrain: Cylinder 2 Injector Circuit Low Causes and Fixes

What's Unique About the 2010-2015 Gmc TERRAIN

For the GMC Terrain and its sibling, the Chevrolet Equinox, this code is frequently not a problem with the injector itself. GM has issued Technical Service Bulletins (TSBs) because the engine wiring harness is prone to rubbing against engine components, particularly on the 2.4L engine. This chafing can cause wires to short to ground, creating the 'low circuit' condition the ECM detects. Common chafe points are on a harness bracket at the upper rear of the engine, near the starter motor, and against the ECM bracket. Owners and 🎬 Watch: Diagnosing a common Equinox wiring harness short circuit technicians familiar with this platform know to check the wiring harness thoroughly before considering injector replacement.

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
• Rough or shaky idle
• Engine misfire, which may feel like a stumble or hesitation
• Reduced engine power and poor acceleration
• Decreased fuel economy
• Engine may stall intermittently

Most Likely Causes

1. Chafed or Shorted Engine Wiring Harness 🔴 High Probability → Shop Engine Wiring Harness As documented in GM TSBs #PIT5424 and #PIP4924D, the engine harness routing makes it susceptible to rubbing against engine components, leading to short circuits. This is a well-known issue, especially on the 2.4L engine. Forum users consistently report finding the damaged wire(s) in a harness that runs down the back of the engine, often rubbing on a bracket or the starter motor housing.
   How to confirm: Visually inspect the entire injector wiring harness. Pay close attention to where the harness is routed near the Engine Control Module (ECM), where it is clipped to a bracket at the upper rear of the engine, and follow it down towards the starter. Look for worn-through conduit, shiny metal spots on brackets, and damaged wires with exposed copper.
   Typical fix: Repair the damaged section of wire. This involves cutting out the bad section, splicing in new wire, soldering the connections, and protecting the repair with heat-shrink tubing. The harness should then be re-secured away from sharp edges or hot surfaces using zip ties and protective conduit. 🎬 See how to properly repair and protect damaged engine wiring
   Est. part cost: $10-$30
2. Failed Fuel Injector 🟡 Medium Probability → Shop Fuel Injector The 2.4L engine uses Gasoline Direct Injection (GDI), and these high-pressure injectors can fail electrically (internal short) or become clogged. While less common than the wiring issue for this specific code, injector failure is still a possibility.
   How to confirm: After confirming the wiring is good, disconnect the injector and measure its resistance with a multimeter. A GDI injector has very low resistance, typically 1-2 ohms. A reading of 0 ohms indicates a dead short, while an infinite reading (O.L.) indicates an open circuit. The 11-14 ohm value often cited is for older port-style injectors and does not apply here. A more definitive test is to swap the suspect injector with one from another cylinder (e.g., swap injector 2 with injector 4). Clear the codes and run the engine. If the code changes to P0270 (Cylinder 4 Injector Circuit Low), the injector is faulty.
   Typical fix: Replace the fuel injector for cylinder 2. For GDI engines, this is more involved than on older port-injection engines and may require special tools and replacement of high-pressure fuel lines and seals.
   Est. part cost: $50-$150
3. Faulty Engine Control Module (ECM) ⚪ Low Probability → Shop Engine Control Module (ECM)
   How to confirm: This should be the last resort after all wiring and the injector itself have been tested and confirmed to be good. A specialized scan tool may be needed to test the injector driver circuit within the ECM. This is rarely the cause.
   Typical fix: Replace the ECM. The new module will need to be programmed to the vehicle's VIN and specific configuration.
   Est. part cost: $300-$700

Rare But Worth Checking

• Corroded or Loose Injector Connector: The electrical connector at the fuel injector can become loose or contaminated with moisture/oil, leading to a poor connection. Always check for clean, tight-fitting pins before performing more complex diagnostics. The locking tab can become brittle and break.

Diagnosis Steps

1. Verify the code is present using an OBD-II scanner. Note any other codes that are present, especially other injector or misfire codes.
2. Perform a thorough visual inspection of the engine wiring harness, focusing on the areas mentioned in TSBs: around the ECM, at the rear of the cylinder head where the harness may be clipped to a bracket, and down the back of the engine towards the starter.
3. If damage is found, repair the wiring. Clear the codes and test drive to see if the code returns.
4. If the wiring appears intact, disconnect the electrical connector at the cylinder 2 fuel injector.
5. Inspect the connector for corrosion, moisture, or damaged pins.
6. Use a multimeter to check the resistance of the fuel injector. A GDI injector should have low resistance (1-2 ohms). A reading near zero or 'O.L.' indicates a failed injector. This test is not always conclusive.
7. A better test is to swap the cylinder 2 injector with another cylinder's injector (e.g., cylinder 4). If the code follows the injector and becomes P0270, the injector is bad.
8. If the injector tests good, check for a signal from the ECM using a 'noid light' or an oscilloscope. With the engine cranking, the noid light should flash, indicating the ECM is sending a pulse. If it stays on solid or doesn't light at all, there is a wiring or ECM issue.
9. If there is no pulse from the ECM and the wiring is confirmed to be good from the injector connector to the ECM pin, the issue may be a faulty ECM injector driver.

Parts You'll Likely Need

• Fuel Injector (OEM #12633784) — If the injector's internal coil has failed its resistance test or the injector swap test, it must be replaced. This is the most common part to fail after wiring issues are ruled out.
  Trusted brands: ACDelco, Delphi, Hitachi
  OEM price range: $100-$150
  Aftermarket price range: $50-$90
• Wiring Repair Supplies — Needed to fix the most common cause of P0264 on this vehicle: a chafed wiring harness. This includes automotive-grade wire, solder, heat-shrink tubing, and high-temperature electrical tape or split-loom conduit.
  Trusted brands: Tesa, 3M
  OEM price range: $10-$30
  Aftermarket price range: $10-$30
• Fuel Injector Connector Pigtail (OEM #PT2160 / Dorman 645-800) — If the electrical connector at the injector is broken, corroded, or damaged during diagnosis, replacing it with a new pigtail is the correct repair. Dorman 645-800 is a commonly cited aftermarket replacement. Always verify the connector shape before purchasing.
  Trusted brands: ACDelco, Dorman, Standard Motor Products
  OEM price range: $20-$40
  Aftermarket price range: $10-$25

Related Codes That Often Appear With This One

• P0302 — This code means 'Cylinder 2 Misfire Detected.' It is a direct result of P0264, as the injector circuit fault prevents proper fueling, causing the cylinder to misfire.
• P0261, P0267, P0270 — These are the same 'Injector Circuit Low' codes for other cylinders. If multiple injector codes appear together, it strongly points to a widespread wiring harness problem affecting a bundle of wires, or a fault with the ECM's power supply.

Technical Service Bulletins (TSBs) & Recalls

• Bulletin #PIT5424: Addresses intermittent hard starts and various injector circuit codes (including P0264) caused by engine harness routing issues near the ECM.
• Bulletin #PIP4924D: Pertains to misfires and multiple injector circuit codes (including P0264) caused by harness chafing.

Platform-Specific Known Issues

• TSB #PIT5424 notes that codes like P0264 can be caused by the engine harness being improperly routed and chafing near the ECM.
• TSB #PIP4924D also lists P0264 with other injector codes and advises inspection of the wiring harness for chafing against components like the intake plenum and cylinder head.
• Real-World Owner Experience: A user on terrainforum.net with a 2011 Terrain reported P0264 and a misfire. After finding no obvious damage at the top of the engine, they located a chafed wire in the harness bundle down near the starter motor. Repairing this single wire resolved the code and the misfire, confirming the TSBs' warnings.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance (GDI Engines) — expected: 1.0 - 2.0 Ohms. Failure: A reading of 0 Ohms indicates a short, while an infinite reading (O.L.) indicates an open circuit.
• Injector Connector Voltage (Control Wire) — expected: Pulsing ground signal when engine is cranking/running (visible on oscilloscope or flashing noid light).. Failure: No pulse, or a constant ground signal, indicates a wiring or ECM driver issue.
• Injector Connector Voltage (Power Feed Wire) — expected: ~12V (Battery Voltage) with Key On, Engine Off.. Failure: Low or no voltage indicates a problem with the power supply from the fuse block.
• High-Pressure Fuel Rail Pressure (GDI Engines, Scan Tool) — expected: ~300-500 PSI at idle, up to 2,000+ PSI under load.. Failure: While not a direct cause for a circuit code, erratic or low pressure can indicate related fuel system problems.

Scan Tool Commands That Help

• GM GDS2 / High-End Bidirectional Scan Tool: Injector Test / Fuel Injector Balance — After checking wiring, use this to confirm if the #2 cylinder is non-responsive. The command disables injectors one by one; disabling cylinder #2 should cause no change in RPM if it's already not firing, confirming the fault's impact.

Wiring & Ground Locations

• Cylinder 2 Injector Control Wire — In the engine harness running from the ECM, down the back of the engine towards the starter. On the 2.4L, this is often a Dark Blue wire.. This specific wire is the one that shorts to ground, directly causing the P0264 code. Its location near brackets and the starter motor makes it the primary point of failure.
• G107 — An engine block ground, typically located on the driver's side of the engine block, sometimes near the starter motor.. A loose or corroded main engine ground can cause a variety of erratic electrical issues, including injector circuit faults. The ECM and sensors need a stable ground reference to function correctly.

Real Owner Repair Stories

• terrainforum.net user report (2011 GMC Terrain 2.4L) — Check engine light with codes P0264 and P0302 (Cylinder 2 Misfire).
  ❌ Tried (didn't work) Swapping ignition coils, Swapping spark plugs
  ✅ What actually fixed it Found a broken/chafed Dark Blue wire in the wiring harness that runs down the back of the engine to the starter. Repairing this single wire resolved both codes.
• equinoxforum.net user report (2012 Chevy Equinox 2.4L) — Multiple injector codes including P0264 and P0270.
  ❌ Tried (didn't work) Replacing the fuel injectors for the affected cylinders (#2 and #4).
  ✅ What actually fixed it Located a section of the wiring harness near the cylinder head where it was held by a plastic clip. The conduit was worn through and multiple wires had their insulation rubbed off, causing them to short against each other. Repairing the damaged wires and re-insulating the harness fixed the issue.

OEM Part Supersession History

• 12633784 → 12669384 — Likely an internal revision by GM for improved reliability or manufacturing process. The original part is associated with failures.
  Heads up: The 3.0L V6 (LF1) and 3.6L V6 (LFX) engines use completely different fuel injectors (e.g., 12638530 for the 3.6L). Part numbers are not interchangeable between engines.

Model Year Variations Within This Range

• 2010-2012 vs 2013-2015: The optional V6 engine changed from the 3.0L LF1 to the 3.6L LFX in model year 2013. While the P0264 code's meaning is the same, the fuel injectors, harness routing, and ECM are different, so diagnostic locations and part numbers will not be the same.
• 2012-2015: The 2.4L engine was updated in 2012 to become E85 Flex Fuel compatible (RPO code LFW). This may involve different fuel injector specifications compared to the 2010-2011 (LAF) engine, but the primary wiring harness chafe issue remains the same across these years.