P2146 on 2010-2014 Cadillac SRX: Fuel Injector Circuit Fault Causes & Fixes

What's Unique About the 2010-2014 Cadillac SRX

The V6 engines used in this generation of the Cadillac SRX are known for a specific wiring harness vulnerability. General Motors issued a Technical Service Bulletin (TSB #PIP4924D) 🎬 Watch: How to find and fix a mangled injector harness that directly links code P2146 to the fuel injector wiring harness rubbing through on various engine components. This makes a wiring fault a much higher probability on this specific vehicle compared to a random component failure.

Diagnostic Flowchart

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

Symptoms You May Notice

• Severe engine misfire or rough running
• Engine is hard to start or will not start
• Engine stalls after starting
• Significant loss of engine power
• Illuminated Check Engine Light

Most Likely Causes

1. Chafed or Damaged Fuel Injector Wiring Harness 🔴 High Probability → Shop Engine Wiring Harness As documented in GM TSB #PIP4924D, the harness routing makes it susceptible to rubbing against engine parts. Common chafe points include against the intake plenum, valve cover bolts, fuel lines, and the side of the cylinder head.
   How to confirm: Perform a careful visual inspection of the entire fuel injector harness, focusing on the areas mentioned in the TSB. Gently wiggle the harness with the engine running (if possible) to see if the misfire changes.
   Typical fix: Repair the broken or shorted wire(s) using solder and heat-shrink tubing. In cases of severe damage, the harness section may need to be replaced.
   Est. part cost: $10-$30
2. Faulty Fuel Injector ⚪ Low Probability → Shop Fuel Injector
   How to confirm: After confirming the wiring is intact, you can test the injectors. Measure the electrical resistance of each injector on the affected bank and compare it to the injectors on the working bank. A significant difference indicates a faulty injector.
   Typical fix: Replace the single failed fuel injector. It is sometimes recommended to replace them as a set if they are high mileage.
   Est. part cost: $70-$180
3. Loose or Corroded Electrical Connector ⚪ Low Probability
   How to confirm: Visually inspect the main harness connector at the ECM and the individual connectors at each fuel injector for corrosion, bent pins, or a loose fit.
   Typical fix: Clean the connector pins with an electrical contact cleaner or replace the connector pigtail if it's damaged.
   Est. part cost: $5-$50

Rare But Worth Checking

• Faulty Engine Control Module (ECM): → Shop Engine Control Module (ECM) This is a rare cause and should only be considered after all wiring and fuel injectors have been thoroughly tested and proven to be good. The internal driver circuit for the injector bank can fail.

Diagnosis Steps

1. Scan the ECM for all stored trouble codes. Note if P2146 is accompanied by any specific injector codes (P0201-P0206).
2. Begin with a thorough visual inspection of the fuel injector wiring harness, as recommended by TSB #PIP4924D. Pay extremely close attention to areas where the harness could rub against the intake manifold, valve covers, or fuel lines.
3. If no damage is visible, use a multimeter to check for continuity on the power supply wire from the ECM connector to the injector connectors on the affected bank.
4. Check for a short to ground on the same power supply wire.
5. If wiring integrity is confirmed, measure the resistance of each fuel injector in the group. Compare the readings to each other; they should be nearly identical. An injector with a significantly different reading is likely faulty.
6. If both the wiring and injectors test good, the final possibility is a failed injector driver circuit within the ECM.

Parts You'll Likely Need

• Fuel Injector Wiring Harness Repair Supplies — The most common cause is a chafed wire that needs to be repaired, not a full harness replacement.
  OEM price range: $10-$30 (for wire, solder, heat shrink)
  Aftermarket price range: $10-$30
• Fuel Injector (OEM #12638530 (for 3.6L LFX)) — If the wiring is intact, a single failed injector is the next most likely component to cause this code.
  Trusted brands: ACDelco, Bosch
  OEM price range: $120-$180
  Aftermarket price range: $70-$110

Related Codes That Often Appear With This One

• P0201, P0203, P0205 — These are individual injector circuit codes for one bank. They often appear with P2146, which is the code for the entire group.
• P0202, P0204, P0206 — These are individual injector circuit codes for the other bank. If you see these with P2149 (Group 'B' fault), it points to the same type of issue on the opposite side of the engine.
• P2149 — This is the equivalent code for Fuel Injector Group 'B'. If both P2146 and P2149 are present, it could indicate a more widespread wiring issue or a problem with the ECM.

Technical Service Bulletins (TSBs) & Recalls

• PIP4924D: States that for codes including P2146, technicians should "Carefully inspect the fuel injector wiring harness for rub through or internal wire opens." It lists common chafe spots against the intake, valve cover bolts, and fuel lines.

Platform-Specific Known Issues

• A known issue documented in GM TSB #PIP4924D points directly to the fuel injector wiring harness chafing or developing an internal open, causing P2146 and related codes.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance (3.0L LF1 V6, 2010-2011) — expected: Approx. 11-14 Ohms. Failure: A reading significantly outside this range, OL (Open Loop), or near zero indicates a faulty injector.
• Fuel Injector Resistance (3.6L LFX V6, 2012-2014) — expected: 1.2 - 1.8 Ohms. Failure: A reading outside this range, OL (Open Loop), or near zero indicates a faulty injector.
• Injector Circuit Voltage (at connector, Key On Engine Off) — expected: One pin should show battery voltage (approx. 12V). The other is the control wire pulsed by the ECM.. Failure: No voltage on the power pin points to a break in the supply wiring from the fuse block.

Wiring & Ground Locations

• G101 — At the left rear of the engine compartment.. This ground serves the Engine Control Module (ECM) and Transmission Control Module (TCM). A poor connection here can cause various erratic electronic issues, including injector circuit faults.
• G102 — Located at the left rear of the engine, grounds the 8 ignition coils.. While not directly for the injectors, a poor ignition system ground can sometimes create electrical noise that may interfere with sensitive ECM readings, although it's an indirect link.
• G105 / G106 — Located at the left front of the engine compartment behind cooling fan relays (G105) and on the front center of the frame cross rail (G106).. These are major chassis and engine block grounds. Corrosion or looseness at these points can affect the entire vehicle's electrical stability, including the power supplied to the ECM and fuel injector circuits.
• Injector Power Splice (e.g., S112 / S119) — Inside the engine wiring harness, where the main power feed from the fuse block splits to feed the individual injectors of one bank.. A failure at this internal splice point would cut power to the entire injector group, directly causing a P2146 code. This is a potential point of failure if external wiring appears intact.
• Connector X106 — This is a major inline harness connector that feeds all the injectors.. A loose pin, corrosion, or damage at this single connector can disable an entire bank of injectors. Checking the integrity of this connector is a key diagnostic step before the ECM.

Real Owner Repair Stories

• YouTube user 'Bungled Project' (Vehicle appears to be a GM with a V6, undergoing an engine-out service, consistent with SRX architecture.) — After re-installing the engine, the car had a rough running condition and threw two codes, P0271 and P2146, related to fuel injector issues.
  ❌ Tried (didn't work) The user immediately suspected a wiring issue from the recent engine work rather than replacing parts.
  ✅ What actually fixed it The user discovered the fuel injector wiring harness was damaged (pinched or cut) during the engine installation. The fix was to cut out the damaged section of wire for the affected injector connector and splice in a new section of wire from a donor harness, which resolved the codes.

Model Year Variations Within This Range

• 2010-2011: These models primarily use the 3.0L LF1 V6 engine. This engine uses high-impedance fuel injectors with a resistance of approximately 11-14 Ohms.
• 2012-2014: These models use the 3.6L LFX V6 engine. This engine uses low-impedance fuel injectors with a resistance of approximately 1.2-1.8 Ohms. The diagnostic resistance values are not interchangeable between the two engines.