P0264 on 2010-2014 Cadillac SRX: Cylinder 2 Injector Circuit Low Causes and Fixes

What's Unique About the 2010-2014 Cadillac SRX

For this generation of Cadillac SRX and other GM vehicles with the 3.0L or 3.6L V6 engines, wiring issues are a known concern. A specific GM Technical Service Bulletin (#PIP4924D) was issued for a wide range of injector codes, including P0264, instructing technicians to carefully inspect the fuel injector wiring harness for damage. More detailed service documents point to specific chafe points, such as the front corner of the left-hand cylinder head, the drive belt idler pulley bracket, the oil dipstick bracket, and where the harness may be pinched near major connectors. This suggests that before condemning the injector itself, a thorough visual inspection of the harness at these specific points is a critical, vehicle-specific diagnostic step.

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 be felt as a stumble or hesitation during acceleration
• Reduced engine power and poor acceleration
• Decreased fuel economy

Most Likely Causes

1. Wiring Harness Issue 🔴 High Probability A GM TSB (#PIP4924D) specifically calls out this issue. The injector harness can rub against multiple points, causing wires to chafe or break. Specific documented chafe points include the front corner of the left-hand cylinder head, the drive belt idler pulley bracket, the oil dipstick bracket, and near the X160 connector.
   How to confirm: Visually inspect the entire fuel injector wiring harness, especially around cylinder #2 and at the specific chafe points mentioned above. Look for any signs of rubbing, exposed copper, or damage. Perform a continuity test on the two wires from the ECM connector to the injector connector.
   Typical fix: Repair the damaged section of wire with a new piece of wire and solder/heat-shrink connections. If the damage is extensive or at the connector, a new harness pigtail may be needed. A YouTube video titled 'CADILLAC SRX MISFIRE' showed a similar intermittent issue being traced to a poor contact in a connector.
   Est. part cost: $10-$40
2. Faulty Fuel Injector (Cylinder 2) 🔴 High Probability → Shop Fuel Injector Fuel injectors are electro-magnetic valves that can fail internally over time due to heat cycles and mileage, leading to an electrical short or open circuit.
   How to confirm: Measure the resistance of the injector with a multimeter; it should be within the manufacturer's specified range. The most definitive test is to swap the cylinder 2 injector with an injector from another cylinder (e.g., cylinder 4). If the code changes to P0270 (Cylinder 4 Injector Circuit Low), the injector is faulty.
   Typical fix: Replace the faulty fuel injector. It is often recommended to replace all injectors on a high-mileage vehicle, but it is not required.
   Est. part cost: $75-$150
3. Powertrain Control Module (PCM) Failure ⚪ Low Probability → Shop Engine Control Module (ECM)
   How to confirm: This should be the last step after confirming the injector and wiring are both in perfect working order. A specialized scan tool may be needed to test the injector driver circuit within the PCM.
   Typical fix: Replace and reprogram the PCM. This typically requires a professional shop or dealership.
   Est. part cost: $300-$800

Rare But Worth Checking

• Poor Engine/Chassis Ground:

Diagnosis Steps

1. Confirm the presence of P0264 with an OBD-II scanner. Check for any other codes, especially P0302.
2. Visually inspect the wiring harness and connector for the cylinder #2 fuel injector. It is located on the front bank, middle cylinder. Pay close attention to areas where the harness may rub, specifically the front corner of the left-hand cylinder head, the drive belt idler pulley bracket, and the oil dipstick bracket, as noted in GM service documents.
3. If no visible damage is found, disconnect the injector and check its resistance with a multimeter. Compare the reading to the manufacturer's specification.
4. To definitively test the injector, swap it with the injector from cylinder #4 (rear bank, middle cylinder). Clear the codes and drive the vehicle. If the code returns as P0270 (Cylinder 4 Injector Circuit Low), the injector is bad.
5. If the code remains P0264 after swapping the injector, the problem is in the wiring or the PCM. Perform a continuity test on both wires running from the PCM connector to the injector connector to check for breaks.
6. Inspect main engine and battery ground connections for corrosion or looseness, as this can cause various electrical faults.
7. If the wiring, injector, and grounds are confirmed to be good, the final possibility is a faulty injector driver in the PCM.
🎬 Watch: Diagnosing a Cadillac SRX injector circuit and ECM issue

Parts You'll Likely Need

• Direct Fuel Injector (OEM #12634126) — This is the most common part to fail that causes code P0264, after ruling out wiring issues. This ACDelco part is the original equipment replacement.
  Trusted brands: ACDelco, Bosch
  OEM price range: $75-$150
  Aftermarket price range: $50-$100
• Fuel Injector Connector Pigtail (OEM #13576411, 12707877 (Verify with VIN)) — If the wiring is damaged at the connector, or the connector itself is broken, a new pigtail is needed to make a solid repair. Several part numbers exist, so confirming with the vehicle's VIN is recommended.
  Trusted brands: ACDelco, Dorman
  OEM price range: $25-$40
  Aftermarket price range: $10-$25

Related Codes That Often Appear With This One

• P0302 — P0302 means 'Cylinder 2 Misfire Detected'. Since P0264 indicates a problem with fuel delivery to cylinder 2, it will almost always be accompanied by a misfire on that same cylinder.
• P0261 — P0261 is 'Cylinder 1 Injector Circuit Low'. If you see multiple injector circuit codes, it strongly points to the common wiring harness issue mentioned in TSB PIP4924D rather than multiple failed injectors.

Technical Service Bulletins (TSBs) & Recalls

• PIP4924D: Addresses a Service Engine Soon (SES) light and misfire with multiple injector-related DTCs, including P0264. The primary instruction is to inspect the fuel injector wiring harness for chafing or internal breaks.

Platform-Specific Known Issues

• GM Technical Service Bulletin PIP4924D explicitly identifies that a Service Engine Soon light with misfires and various injector codes (including P0264) can be caused by the fuel injector wiring harness rubbing through. Follow-up documents specify inspecting the harness for damage against the intake, valve covers, fuel lines, the front corner of the left cylinder head, and the drive belt idler pulley bracket before replacing any parts.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance (2012-2014 3.6L LFX V6) — expected: 1.2 - 1.8 Ohms. Failure: A reading of OL (open circuit), near zero (short circuit), or outside the specified range indicates a faulty injector.
• Fuel Injector Resistance (2010-2011 3.0L LF1 V6) — expected: 11 - 14 Ohms. Failure: A significant deviation from this range, OL, or near zero indicates a faulty high-impedance injector.
• High-Pressure Fuel Rail (3.0L LF1 V6) — expected: ~508 PSI at idle, up to 1740 PSI under load.. Failure: Pressure that is significantly low or does not increase with engine demand can indicate a failing high-pressure fuel pump (HPFP).
• High-Pressure Fuel Rail (3.6L LFX V6) — expected: 300 - 500 PSI at idle, rising to over 2,000 PSI under load.. Failure: Pressure that is significantly low or does not increase with engine demand can indicate a failing high-pressure fuel pump (HPFP).
• Injector Circuit Voltage (at connector) — expected: One pin should show battery voltage (~12V) with key on, engine off. The other pin is the control wire, which is pulsed to ground by the ECM.. Failure: No voltage on the power pin points to a wiring issue from the fuse block. No pulsing ground signal (using a noid light) during cranking indicates a wiring or PCM driver issue.

Scan Tool Commands That Help

• GDS2 / Tech 2 (or equivalent professional scanner): Fuel Injector Balance Test — This bidirectional test is used to confirm a suspected faulty injector without removing it. The scan tool commands each injector to fire for a set duration and measures the corresponding drop in fuel rail pressure. A cylinder whose pressure drop is significantly different from the others indicates a faulty injector (either leaking or not flowing enough).

Wiring & Ground Locations

• ECM Pin J2-16 — On the 73-way J2 connector at the Engine Control Module (ECM).. This is the specific pin for the Cylinder 2 Fuel Injector control circuit. The wire color is typically Light Blue. This is the endpoint for continuity testing from the injector connector.
• Connector 106 (C106) — A large harness connector that feeds the bank of injectors.. This is a common junction where wiring problems can occur. A diagnostic video for a similar GM vehicle showed checking continuity from this connector to the individual injector plugs.
• G103 — On GM vehicles, this is often located at the rear of the engine compartment on the cowl, sometimes above the brake booster.. This ground serves numerous components in the engine bay and instrument panel. While not directly for the injector circuit, a poor connection here can cause widespread, erratic electrical issues that could potentially affect ECM operation.

Real Owner Repair Stories

• YouTube - 'Cadillac SRX 2005 P0202/P0302 injector ECM issue.' (2005 Cadillac SRX (Note: First generation, but demonstrates a valid diagnostic path for the V6 engine family)) — P0202 and P0302 codes, misfire on cylinder 2.
  ❌ Tried (didn't work) Swapping fuel injectors (the misfire stayed on cylinder 2)., Inspecting the wiring harness under the intake manifold for damage., Ohm testing the wiring from the main harness connector to the injector plugs.
  ✅ What actually fixed it The ECM was faulty. The owner confirmed the injector and the entire wiring circuit were good by measuring resistance from the fuse box, through the wiring and injector, all the way to the ECM connector pin. The reading was correct (~12.1 Ohms), proving the external circuit was intact and condemning the internal injector driver in the ECM.

OEM Part Supersession History

• 12634126 (For 3.6L LFX) → N/A — This remains the current OEM part number for the 3.6L LFX engine's fuel injector.
• 12629927 (For 3.0L LF1) → N/A — This remains the current OEM part number for the 3.0L LF1 engine's fuel injector.

Model Year Variations Within This Range

• 2010-2011: Models with the 3.0L LF1 V6 use high-impedance fuel injectors (ACDelco #12629927) with a resistance of approximately 11-14 Ohms. The high-pressure fuel system idles around 508 PSI.
• 2012-2014: Models with the 3.6L LFX V6 use low-impedance fuel injectors (ACDelco #12634126) with a resistance of approximately 1.2-1.8 Ohms. These injectors are not interchangeable with the high-impedance type. The high-pressure fuel system idles around 300-500 PSI.