P0011 on 2010-2017 GMC Terrain 2.4L: Causes and Fixes for Over-Advanced Camshaft Timing

What's Unique About the 2010-2017 GMC Terrain

The 2.4L Ecotec engine used in this generation of GMC Terrain and its platform-mate, the Chevy Equinox, has a well-documented history of excessive oil consumption due to a piston ring design flaw. This single issue is the root cause of most P0011 codes on this vehicle. Low oil levels or degraded, sludgy oil starves the VVT system's components, leading to the failure of the camshaft actuator solenoids or, in more severe cases, stretching the timing chain. GM issued several Special Coverage Adjustments (e.g., 14159, 15285C) to address the oil consumption by replacing pistons and rings on affected vehicles.

Symptoms You May Notice

• Engine stalling, often when coming to a stop 🎬 Watch: How a faulty solenoid causes stalling and rough idle. or when giving it gas from a stop.
• Rough or unstable idle.
• Engine hesitation or lack of power during acceleration.
• Reduced fuel economy.
• Hard starting.
• Rattling noise from the engine, especially a sharp rattle for a few seconds on a cold start.
• Check Engine Light is on.

Most Likely Causes

1. Low or Dirty Engine Oil 🔴 High Probability These 2.4L Ecotec engines are known for excessive oil consumption, which frequently leads to low oil levels between changes. Sludge from extended oil change intervals can clog the fine mesh screens on the VVT solenoids.
   How to confirm: Check the engine oil dipstick. The level should be within the cross-hatched area. Inspect the oil's color and consistency; if it is black, thick, or sludgy, it needs to be changed. Many owners recommend checking the oil level every 500 miles.
   Typical fix: If the oil is low, top it off with 5W-30 full synthetic oil meeting Dexos1 specifications. If the oil is old or dirty, perform a complete oil and filter change. Clear the codes and see if P0011 returns.
   Est. part cost: $30-$70
2. Faulty Intake Camshaft Position Actuator Solenoid 🔴 High Probability The solenoids get clogged with debris from dirty oil or fail electronically due to heat exposure on top of the engine. It's a very common failure point on this engine.
   How to confirm: Swap the intake solenoid (gray connector, front of the engine) with the exhaust solenoid (black connector, rear). Clear the codes and drive. If the code changes to P0014 (for the exhaust cam), the solenoid is confirmed bad. You can also test the solenoid's resistance with a multimeter; it should be between 8 and 13 ohms. 🎬 See this video for a step-by-step solenoid resistance test.
   Typical fix: Replace the intake camshaft position actuator solenoid. GM Technical Service Bulletin #17-NA-098 recommends replacing both the intake and exhaust solenoids at the same time to prevent future issues. Use genuine ACDelco parts for longevity; some aftermarket solenoids are reported to fail quickly.
   Est. part cost: $25-$60
3. Stretched Timing Chain or Failed Tensioner 🟡 Medium Probability Running the engine with low oil pressure (from low oil levels) starves the hydraulic timing chain tensioner, allowing the chain to become slack, wear out the plastic guides, and stretch over time.
   How to confirm: Listen for a distinct, sharp rattling noise from the engine for a few seconds on a cold startup. This is a strong indicator. A mechanic can also use a scan tool to measure camshaft deviation, which will be out of spec if the chain is stretched. This is often accompanied by codes P0016 or P0017.
   Typical fix: This is a major repair that involves replacing the entire timing chain kit, which includes the chain, tensioner, all plastic guides, and often the water pump and VVT phasers as well.
   Est. part cost: $150-$500

Rare But Worth Checking

• Failed Intake Camshaft Phaser (Actuator): The phaser is the mechanical gear that actually adjusts the timing. While less common than a solenoid failure, it can get stuck or fail internally, especially if the engine has a history of oil sludge. This is a complex repair often done along with a timing chain replacement. In some cases, a new phaser has been found to be faulty out of the box, causing the code to persist after a timing job.
• Clogged Solenoid Screens: The valve cover and the camshaft bearing caps have small oil filter screens that can become clogged with sludge, restricting oil flow to the phasers and solenoids. If replacing solenoids doesn't fix the issue, these screens may need to be inspected and cleaned, which requires removing the valve cover.

Diagnosis Steps

1. Check the engine oil level and condition immediately. If low, top it off with full synthetic 5W-30 oil. If dirty, change the oil and filter. This is the most critical first step.
2. Scan for other trouble codes. Codes like P0010, P0014, P0016, or P0017 provide critical clues to the root cause.
3. If oil level is correct, test the intake camshaft actuator solenoid. Swap the intake and exhaust solenoids. They are located on top of the valve cover, held by a single 10mm bolt each. The intake solenoid has a gray connector (front), and the exhaust has a black one (rear).
4. Clear the codes and drive the vehicle. If the code returns as P0014, the solenoid you moved to the exhaust position is faulty and must be replaced. It is highly recommended to replace both at the same time per TSB 17-NA-098.
5. If the code P0011 returns after the swap, the problem is not the solenoid. Before assuming a timing chain issue, inspect the solenoid connector and wiring for any damage or corrosion.
6. Listen carefully for a rattling noise from the engine during a cold start. A rattle strongly suggests a stretched timing chain.
7. If a timing chain issue is suspected, consult a professional or prepare for a significant DIY job. The repair requires significant engine disassembly.

Parts You'll Likely Need

• Intake Camshaft Position Actuator Solenoid (OEM #12679099 (supercedes 12655420, 12646783, 12628347, 12578517)) — This is the most common part to fail, usually due to clogging from dirty oil or electronic failure. The OEM part number has been updated several times.
  Trusted brands: ACDelco (GM Genuine), Dorman
  OEM price range: $35-$60
  Aftermarket price range: $20-$40
• Exhaust Camshaft Position Actuator Solenoid (OEM #12679100 (supercedes 12655421)) — TSB 17-NA-098 recommends replacing both solenoids at the same time, as they wear at similar rates under the same oil conditions. The connectors are keyed differently so they cannot be installed in the wrong position.
  Trusted brands: ACDelco (GM Genuine), Dorman
  OEM price range: $35-$60
  Aftermarket price range: $20-$40
• Timing Chain Kit (OEM #12680750) — Required if the timing chain is stretched, which is the second most likely cause after the solenoids, especially if a startup rattle is present. Kits often include chains, guides, tensioners, and sprockets.
  Trusted brands: ACDelco (GM Genuine), Cloyes
  OEM price range: $150-$250
  Aftermarket price range: $100-$200

Related Codes That Often Appear With This One

• P0010 — This code indicates an electrical circuit malfunction for the intake camshaft actuator solenoid. It often appears with P0011 if the solenoid has an internal short or open circuit.
• P0014 — This is the same timing code but for the exhaust ('B') camshaft. Seeing P0011 and P0014 together often points to a systemic issue like low/dirty oil affecting both VVT solenoids, or both solenoids failing around the same time.
• P0016 / P0017 — These codes indicate a loss of synchronization between the crankshaft and camshaft(s). They are a very strong sign of a stretched or jumped timing chain and represent a more severe mechanical failure than P0011 alone.
• P0300 — A random misfire code can be triggered by the erratic camshaft timing causing combustion instability in multiple cylinders.

Technical Service Bulletins (TSBs) & Recalls

• 17-NA-098: For rough running, hesitation, and codes P0010, P0011, P0013, or P0014. Recommends replacing BOTH camshaft position actuator solenoid valves and verifying the ECM has the latest software. An updated version from 2019 lists new part numbers (12679099/12679100).
• PIP4716F: Notes that a startup rattle accompanied by codes like P0011 can point to a timing chain issue.
• Special Coverage Adjustment 14159 / 14159D: Addresses excessive oil consumption on 2010 models, a root cause of oil-related DTCs.

Platform-Specific Known Issues

• This engine is subject to a class-action lawsuit and multiple GM Special Coverage Adjustments (e.g., #14159 for 2010 models, #15285C for 2011) regarding excessive oil consumption, which is the primary catalyst for P0011 and other VVT issues.

Mechanic-Grade Diagnostic Values

• Camshaft Position Actuator Solenoid Resistance — expected: 8 to 13 Ohms. Failure: A reading of OL (open circuit), near zero (short), or a reading that fluctuates wildly when wiggling the connector pins indicates a failed solenoid.
• Scan Tool: Desired vs. Actual Camshaft Position Angle — expected: The 'Intake Camshaft Position Angle' and 'Desired Intake Camshaft Position Angle' PIDs should match within a few degrees at idle and under load.. Failure: A persistent variance greater than +/- 4-6 degrees at idle strongly suggests a mechanical timing issue like a stretched chain. The ECM may set the code if it sees a variance of more than 8 degrees for over 20 seconds.
• Solenoid Connector Voltage (Key On, Engine Off) — expected: Approximately 12.6V (battery voltage) on the power supply pin.. Failure: No voltage suggests a wiring or fuse issue upstream of the connector. The other pin is the control wire pulsed to ground by the ECM.
• Engine Oil Pressure (Hot Idle) — expected: At least 20-25 PSI.. Failure: Pressure dropping below 20 PSI at a hot idle can starve the VVT system and trigger timing codes, even if other components are good.

Scan Tool Commands That Help

• GDS2 / Tech2: Camshaft Position Actuator Solenoid Test — This bidirectional command allows the technician to manually command the solenoid on and off (or in duty cycle percentages) while the engine is idling. A working solenoid and phaser will cause a noticeable drop in RPM or may stall the engine. If there is no change in engine operation, it confirms a fault in the solenoid, its circuit, or the oil passages/phaser.

Wiring & Ground Locations

• G105 — On the lower left front of the engine block.. This is a primary engine block ground. A poor connection here can cause erratic behavior from the ECM and its sensors, including the camshaft and crankshaft position sensors which are critical for VVT operation.
• G107 — An engine ground strap, 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 electrical faults. TSBs for other electrical issues on this platform often point to checking G107, as it is a critical ground path for the powertrain.
• Intake VVT Solenoid Connector — On top of the valve cover, front-most solenoid, gray connector.. This is the direct electrical connection for the component most likely to fail. One pin should have battery voltage with key-on-engine-off, the other is the control signal from the ECM. Wiggling the connector during resistance testing can reveal intermittent internal solenoid faults.

Real Owner Repair Stories

• equinoxforum.com user report (2017 GMC Terrain 2.4L) — Check Engine Light with codes P0011, P0016, and P228D (fuel pressure) appearing after a few miles of driving.
  ❌ Tried (didn't work) Replaced timing chain kit (Cloyes brand), even though the original chain did not appear stretched and timing marks were aligned.
  ✅ What actually fixed it The owner replaced the intake VVT solenoid and the intake camshaft position sensor with genuine GM/ACDelco parts and cleaned the reluctor wheel on the camshaft. This resolved the codes.

OEM Part Supersession History

• 12628347, 12646783, 12655420 → 12679099 — GM has updated the part several times to improve reliability and durability against heat and oil contamination.
  Heads up: All listed part numbers are for the intake solenoid and are interchangeable, with 12679099 being the latest and most recommended version.

Model Year Variations Within This Range

• 2010 (early production): GM Bulletin #PIP4716F and others mention the possibility of machining debris or casting sand from the engine block/head manufacturing process clogging VVT oil passages on engines built before August/September 2009. This could cause a persistent P0011 that is not resolved by replacing solenoids.

Diagnostic Flowchart

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0010 — Intake Camshaft Position Actuator Circuit code. Often appears alongside P0011 when the intake VVT solenoid fails electronically, as noted in TSB 17-NA-098.
• P0014 — Exhaust Camshaft Position System Performance code. This is the exhaust-side equivalent of P0011. It will appear during diagnosis if you swap a faulty intake solenoid to the exhaust position.
• P0016 — Crankshaft Position - Camshaft Position Correlation code. Frequently accompanies P0011 when the root cause is a stretched timing chain or failed tensioner.
• P0017 — Crankshaft Position - Camshaft Position Correlation code. Similar to P0016, this code appears alongside P0011 when the timing chain has stretched out of specification.
• P0013 — Exhaust Camshaft Position Actuator Circuit code. Listed in TSB 17-NA-098 as a related code that shares the same rough running symptoms and solenoid replacement fix.
• P228D — Fuel Pressure Regulator Control Performance - High Pressure. Reported by owners as appearing concurrently with P0011 and P0016 when dealing with severe timing chain and VVT sensor issues.

Frequently Asked Questions