P0013 on 2006-2010 Hummer H3 3.7L: Exhaust Camshaft Solenoid Circuit Causes and Fixes

What's Unique About the 2006-2010 Hummer H3

The Hummer H3 uses the GM Atlas engine family (3.5L L5 in 2006, 3.7L L5 in 2007-2010), which it shares with the Chevrolet Colorado and GMC Canyon on the GMT355 platform. Across this entire platform, failure of the camshaft position actuator solenoids (also called VVT solenoids or oil control valves) is an extremely common and well-documented issue. The solenoids are identical for intake and exhaust, easily accessible on top of the engine, and known to fail electrically, making P0013 a frequent and straightforward diagnosis for owners.

Generation note: The Hummer H3 had one generation (2006-2010). However, the engine was updated from the 3.5L L5 in the 2006 model to the 3.7L L5 for 2007-2010 models. This guide applies to both engine versions as the VVT system design, the solenoids (Part No. 12615873), and the troubleshooting for code P0013 are virtually identical.

Symptoms You May Notice

• Check Engine Light is on
• Rough or unstable engine idle
• Engine may stall at low speeds or when stopping
• Noticeable loss of power and sluggish acceleration
• Worse than normal fuel economy
• Engine hesitation
• Engine running louder than usual or rattling

Most Likely Causes

1. Failed Exhaust Camshaft Position Actuator Solenoid 🔴 High Probability → Shop Engine Camshaft This is a widely documented, common failure part on the GM Atlas engine family used in the H3, Colorado, and Canyon. The solenoids are subjected to heat and oil contaminants, leading to electrical failure of the internal coil.
   How to confirm: Swap the exhaust solenoid with the identical intake solenoid. Clear the codes. If the code changes to P0010 (Intake 'A' Circuit), the solenoid is bad. Alternatively, test the solenoid's resistance with a multimeter; it should be between 6.9 and 7.9 ohms at 68°F (20°C). An open circuit (no reading) or a reading far outside this range confirms failure.
   Typical fix: Replace the exhaust camshaft position actuator solenoid. Many owners choose to replace both the intake and exhaust solenoids at the same time as a preventative measure, as they are the same age and operate under the same conditions.
   Est. part cost: $25-$50
2. Dirty or Low Engine Oil 🟡 Medium Probability The VVT system is hydraulic and highly sensitive to oil pressure and cleanliness. Oil sludge or low levels can clog the fine mesh screens on the solenoid, preventing it from functioning correctly even if it's electrically sound.
   How to confirm: Check the engine oil dipstick for low oil level or a dark, sludgy consistency. If the oil hasn't been changed according to the manufacturer's schedule, this is a likely contributor.
   Typical fix: Perform an engine oil and filter change using the manufacturer-recommended oil viscosity (5W-30). In some cases, simply cleaning the solenoid screens and performing an oil change can resolve the code.
   Est. part cost: $40-$70
3. Damaged Wiring or Electrical Connector ⚪ Low Probability
   How to confirm: Visually inspect the wiring harness and connector going to the exhaust VVT solenoid. Look for frayed or broken wires, corrosion on the pins, oil contamination in the connector, or a loose connection. Use a multimeter to check for battery voltage at the power supply pin of the connector with the ignition on.
   Typical fix: Repair the damaged section of wiring or replace the connector pigtail. Clean any corrosion from the connector pins with electrical contact cleaner.
   Est. part cost: $10-$25

Rare But Worth Checking

• Failed Powertrain Control Module (PCM): This is extremely rare. The PCM should only be considered after all other possibilities, including the solenoid and the entire wiring circuit, have been thoroughly tested and ruled out.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P0013 is present.
2. Check the engine oil level and condition. If low or dirty, perform an oil and filter change with 5W-30 oil before proceeding.
3. Locate the two VVT solenoids on the top of the engine's valve cover. The exhaust solenoid is the one closer to the rear (firewall).
4. Inspect the electrical connector and wiring for the exhaust solenoid for any obvious damage, corrosion, or loose fitment.
5. For the most definitive and common DIY test, swap the exhaust solenoid with the intake solenoid (they are identical and interchangeable). They are each held in by a single 10mm bolt.
🎬 Watch: This quick walkthrough shows how to replace the solenoids.
6. Clear the trouble codes with the scanner, start the engine, and let it run for a minute or take a short drive.
7. Re-scan for codes. If code P0010 ('A' Camshaft Position Actuator Circuit) now appears, the solenoid you moved to the intake position is faulty and must be replaced.
8. If the P0013 code returns, the problem is likely in the wiring harness or the PCM's driver circuit for that solenoid. Test the wiring for continuity and check for voltage at the connector.
9. (Optional) Test the resistance of the suspect solenoid using a multimeter. Disconnect the solenoid and measure across its two pins. A reading outside the 6.9-7.9 ohm range indicates it has failed electrically.

Parts You'll Likely Need

• Camshaft Position Actuator Solenoid (OEM #12615873) — This is the most common failure point for code P0013 on this engine. It is an electro-hydraulic solenoid that controls oil flow to the camshaft phaser.
  Trusted brands: ACDelco (GM Original Equipment), Delphi, Dorman (917-010), Gates (VVS145), Standard Motor Products (VVT102)
  OEM price range: $40-$60
  Aftermarket price range: $25-$45

Related Codes That Often Appear With This One

• P0014 — P0014 ('B' Camshaft Position - Timing Over-Advanced) often appears with P0013 because a failing solenoid circuit (P0013) can cause the camshaft timing to become stuck or respond incorrectly, leading to a performance/position error (P0014).
• P0010 — P0010 is the equivalent circuit code for the intake ('A') camshaft solenoid. If you swap the solenoids for diagnosis and the fault moves from the exhaust to the intake position, you will see P0010 instead of P0013.
• P0017 — P0017 (Crankshaft Position - Camshaft Position Correlation) can sometimes appear alongside P0013, especially if the timing chain has stretched or if the underlying circuit fault is causing erratic camshaft phaser behavior.

Technical Service Bulletins (TSBs) & Recalls

• While no TSB is specific to the H3 3.7L for P0013, GM TSB 17-NA-098 addresses the same set of codes (P0010, P0013, P0011, P0014) on other GM engines, identifying camshaft position actuator solenoid failure as the cause and recommending replacement.
• Ford TSB 15-0160 for the 3.7L Duratec engine (a different engine family) also lists P0013 as a possible DTC resulting from a chafed wiring harness near the transmission, highlighting that wiring should not be overlooked as a potential cause for this code on any vehicle.

Platform-Specific Known Issues

• The GM Atlas I4, I5, and I6 engines used across the H3, Colorado, Canyon, and Trailblazer platforms are all known for frequent VVT solenoid failures, making this a predictable maintenance item.
🎬 Watch: Why these VVT solenoids are a critical maintenance item.
• Real Owner Stories: On HummerForums.com, multiple owners report the P0013 code appearing, performing the solenoid swap test, and confirming the solenoid is bad when the code changes to P0010. The fix is consistently reported as a simple replacement of the faulty solenoid. A user on 355nation.net (a Colorado/Canyon forum) with a 3.7L engine described the classic symptoms of rough idle and stalling, which were completely resolved by replacing both VVT solenoids in under 30 minutes.

Mechanic-Grade Diagnostic Values

• Exhaust VVT Solenoid Coil Resistance — expected: 6.9 to 7.9 Ohms at 68°F (20°C). Failure: An open circuit (infinite resistance) or a reading significantly outside the specified range indicates a failed coil.
• VVT Solenoid Connector Voltage — expected: Battery voltage (approx. 12V) on one of the two pins with Key On, Engine Off.. Failure: No voltage suggests a problem with the power supply circuit, such as a blown fuse or broken wire.

Scan Tool Commands That Help

• Tech2 or equivalent professional scan tool: Camshaft Position Actuator Test — This bidirectional control allows a technician to command the solenoid on and off, or to a specific duty cycle percentage, while monitoring the actual camshaft angle. If the ECM commands the solenoid but the cam angle doesn't change, it confirms a fault in the solenoid, oil pressure, or the mechanical phaser. This is used to verify the entire system's functionality after confirming the electrical circuit is intact.

Wiring & Ground Locations

• G102 / G103 — On the lower left side of the engine block.. These are primary engine block grounds. A poor connection here can create voltage discrepancies for engine-mounted components and sensors, potentially causing erratic behavior or fault codes.
• G104 — On the left side of the engine block, in front of the starter.. Another critical engine block ground. Ensuring it is clean and tight is a key step when troubleshooting any electrical fault that isn't solved by replacing the primary component.
• G105 — On the left inner front wheel well, behind the battery.. This is a major chassis and engine bay ground point. A fault here can cause widespread, difficult-to-diagnose electrical issues across multiple systems.

Real Owner Repair Stories

• HummerForums.com user post (2006 Hummer H3) — Check engine light with codes P0013 and P0014, rough start, and stalling at stops.
  ❌ Tried (didn't work) Initial diagnosis was complicated by a recent engine replacement.
  ✅ What actually fixed it The owner reported the shop replaced the camshaft actuator (solenoid) and also repaired a related wire. The combination of the new part and the wiring fix resolved the codes and symptoms.

OEM Part Supersession History

• 12568078 → 12576768, 12597025, 12602516, 12615873 — Standard part evolution and design updates by GM over the production life of the Atlas engine family.

Model Year Variations Within This Range

• 2006 vs. 2007-2010: The 2006 H3 used the 3.5L L52 engine, while 2007-2010 models used the 3.7L LLR. While the VVT solenoids are interchangeable, other related top-end components are not. For example, the valve covers are different due to different spark plug well shapes, and the camshaft phaser sprockets (actuators) themselves are different part numbers.

Diagnostic Flowchart

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For the VVT solenoid causing code P0013, buying a used part is strongly discouraged. The part is a known high-failure item, is inexpensive to buy new, and the labor to replace it is minimal. The risk of a used part failing shortly after installation outweighs any potential cost savings.

What to inspect on the donor part:

• Not applicable as used purchase is not recommended.

OEM-only on this vehicle (don't cheap out):

• No parts for this specific repair are considered OEM-only. Quality aftermarket solenoids are widely available and perform well.

Aftermarket brands forum-validated for this vehicle:

• ACDelco (OEM)
• Delphi
• Dorman
• Standard Motor Products (SMP)
• Gates

Brands owners have reported issues with on this vehicle:

• Unnamed or generic brands from online marketplaces like Amazon or eBay are a gamble. While some may work, many owners report premature failures or out-of-box issues compared to established brands.

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 'A' Camshaft Position Actuator Circuit. This is the direct companion code for the intake solenoid. It commonly appears during diagnosis after a faulty exhaust solenoid (causing P0013) is swapped to the intake side, confirming the solenoid is the problem.
• P0014 — Exhaust 'B' Camshaft Position - Timing Over-Advanced. This is a performance/timing code for the same exhaust camshaft. A faulty solenoid causing the P0013 circuit code can also fail to correctly position the camshaft, triggering this timing-related code.
• P0017 — Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B). This code indicates a timing mismatch between the crank and exhaust cam. A non-responsive solenoid (causing P0013) can prevent the cam from phasing as commanded by the PCM, leading to this correlation error.
• P0011 — Intake 'A' Camshaft Position - Timing Over-Advanced. This is the intake-side equivalent of P0014. It is mentioned in GM TSB 17-NA-098 as part of the same family of VVT codes that can be caused by solenoid failure or dirty oil.

Frequently Asked Questions