P0201 on 2021-2022 Chevrolet Tahoe: Injector Circuit Malfunction Causes & Fixes

What's Unique About the 2021-2022 Chevrolet TAHOE

For the 2021-2022 Tahoe and its platform mates (Silverado, Sierra, Yukon, Escalade), this is not just a random part failure. General Motors has released multiple Technical Service Bulletins (TSBs) acknowledging specific, widespread problems that cause this code. TSB #21-NA-149 details numerous points where the engine wiring harness can chafe against chassis and engine components, causing a short or open circuit. TSB #22-NA-087 specifically recommends replacing both the fuel injector and its wiring harness to correct the condition, particularly on diesel models. 🎬 Watch: Troubleshooting injector circuit codes on Duramax diesel engines. This makes it critical to inspect the wiring harness thoroughly before replacing an injector, as a harness issue can mimic a failed injector and is a very common root cause on this platform.

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.
• Engine misfires, creating a noticeable vibration or shudder.
• Rough or unstable idle.
• Hesitation or loss of power during acceleration.
• Reduced fuel economy.
• Strong fuel smell from the engine bay if the injector is physically leaking.
• Flashing Check Engine Light, indicating a severe misfire that can damage the catalytic converter.

Most Likely Causes

1. Damaged Engine Wiring Harness 🔴 High Probability GM TSB #21-NA-149, which supersedes earlier bulletins like #PIT5751C, provides extensive detail on this known issue. Engine vibration causes the harness to rub against sharp metal edges, leading to shorts or open circuits.
   How to confirm: Visually inspect the engine wiring harness, especially at the specific chafe points identified in TSB #21-NA-149: the driver-side upper control arm, the shock tower bolt, the ECM/TCM bracket, the alternator bracket, and where the harness crosses the camshaft cover. Also inspect the main harness connector X160 for poor terminal tension.
   Typical fix: Repair the damaged section of the harness using approved splicing techniques and protect it with abrasion-resistant tape or conduit. Secure the harness away from the point of contact. In severe cases, the entire engine harness may need replacement.
   Est. part cost: $10-$50 for a repair pigtail, $800-$1500 for a full engine harness.
2. Faulty Cylinder 1 Fuel Injector 🔴 High Probability GM TSB #22-NA-087 explicitly calls for the replacement of the fuel injector to correct a P0201 code, indicating a known issue with the part itself, which can fail internally. Another bulletin, #PIP5891C, also notes that a faulty injector is a likely cause and advises against replacing the ECM.
   How to confirm: Swap the cylinder 1 injector with an injector from another cylinder (e.g., cylinder 3). Clear the codes and run the engine. If the code changes to P0203, the injector is faulty. Alternatively, measure the injector's internal resistance. For the 5.3L/6.2L gas engines, it should be very low, around 1.5-2.2 Ω. For the 3.0L diesel, it's much higher, around 160k-190k Ω. An open or shorted reading confirms a bad injector.
   Typical fix: Replace the faulty fuel injector. For the 3.0L Duramax, GM recommends replacing the injector wiring harness at the same time per TSB #22-NA-087. It is also best practice to replace all seals when an injector is serviced.
   Est. part cost: $110-$185 for a single injector.
3. Poor Electrical Connection 🟡 Medium Probability Vibrations and heat cycles can cause connectors to become loose or terminals to lose tension. TSB #22-NA-087 specifically mentions a broken terminal pin inside the injector harness connector as a possible cause for this code on diesel models.
   How to confirm: Inspect the electrical connector at the fuel injector and the main harness connector (X160) for loose, spread, or corroded pins. A 'noid' light can be used to verify if the electrical pulse is reaching the injector connector; it should flash steadily while the engine is running.
   Typical fix: Clean the connector terminals with electrical contact cleaner. If a terminal is broken or has lost tension, replace the pigtail connector.
   Est. part cost: $15-$50

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): This is a last-resort diagnosis. The PCM's internal driver for the injector can fail, but this is far less common than a wiring or injector fault. TSB #PIP5891C specifically advises against replacing the ECM until the injector itself has been ruled out. All other possibilities must be exhausted before condemning the PCM.

Diagnosis Steps

1. Scan the vehicle for codes and confirm P0201 is present. Note any other codes, especially P0301 or other P020x codes.
2. Locate Cylinder 1: On the V8 engines, this is the front-most cylinder on the driver's side.
3. Visually inspect the cylinder 1 fuel injector connector for damage, looseness, or corrosion.
4. Perform a thorough visual inspection of the engine wiring harness for chafing, as detailed in GM TSB #21-NA-149. Key areas include near the alternator, driver-side upper control arm, shock tower bolt, and ECM/TCM bracket.
5. If no visible damage is found, use a 'noid' light on the cylinder 1 injector connector. Start the engine and check for a steady flashing light, which confirms the PCM is sending a pulse signal.
6. If the noid light flashes, the problem is likely the injector. If it does not flash, the problem is in the wiring or the PCM.
7. The most definitive test is to swap the cylinder 1 injector with another one (e.g., cylinder 3). Clear the codes, run the engine, and see if the fault code 'moves' to the new cylinder (P0203). If it does, the injector is bad. If P0201 returns, the problem is in the wiring harness or PCM.
8. If the wiring is suspected (no noid light flash), disconnect the battery. Test for continuity (less than 1 ohm resistance) on both wires between the injector connector and the PCM connector. Also test each wire for a short to ground and a short to voltage.

Parts You'll Likely Need

• Fuel Injector (5.3L/6.2L V8) (OEM #12710481) — This is one of the two most common failures for this code on the gasoline engines, as identified by GM's own service bulletins.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $130-$185
  Aftermarket price range: $70-$120
• Fuel Injector (3.0L Duramax Diesel) (OEM #55506244) — This is the specific injector called for in TSB #22-NA-087 for addressing injector circuit codes on the diesel models.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $150-$220
  Aftermarket price range: $90-$140
• Fuel Injector Connector Pigtail (OEM #ACDelco PT2183 (verify fitment)) — If the wiring is damaged right at the connector, or if the connector itself has a broken pin as noted in TSB #22-NA-087, replacing the pigtail is the standard repair.
  Trusted brands: ACDelco, Dorman
  OEM price range: $30-$50
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• P0301 — P0301 means "Cylinder 1 Misfire Detected." Since P0201 indicates a problem with the fuel supply to cylinder 1, a misfire is a direct and very common consequence.
• P0202, P0203, P0204, etc. — If multiple injector codes appear simultaneously, it strongly suggests a wiring harness issue that is affecting several injector circuits at once, as described in TSBs #PIT5751C and #22-NA-087.
• P0216 — This code for "Injector Timing Control Circuit" can appear alongside injector codes on the 3.0L Duramax diesel models, as noted in TSB #22-NA-087, pointing to a more complex fuel system fault.

Technical Service Bulletins (TSBs) & Recalls

• 22-NA-087: Procedure to replace the fuel injector and wiring harness for P0201-P0206.
• PIT5751C: Instructs inspection of the engine wiring harness for damage for P0201.
• 21-NA-149: Details specific engine harness chafing locations that can cause this code.

Platform-Specific Known Issues

• TSB #22-NA-087: Addresses a condition where the Malfunction Indicator Lamp is on with codes P0201-P0206 set, particularly on 3.0L Duramax models. The bulletin states the cause may be a broken terminal pin inside an injector connector and instructs technicians to replace both the affected fuel injector and the injector wiring harness.
• TSB #21-NA-149: This is a comprehensive bulletin that supersedes several earlier ones. It provides detailed illustrations of multiple locations on the 2021-2022 Tahoe/Suburban and sibling trucks where the engine wiring harness is known to chafe and short out, causing a wide variety of electrical DTCs, including injector circuit faults like P0201.
• TSB #PIT5751C: This preliminary bulletin (now superseded by 21-NA-149) was one of the first to instruct dealership technicians to inspect the engine wiring harness for damage when encountering P0201 and related codes.

Mechanic-Grade Diagnostic Values

• Fuel Injector Coil Resistance (5.3L/6.2L Gas) — expected: 11-18 Ohms is a typical range for many GM high-impedance injectors.. Failure: A reading of infinity (open circuit) or near-zero (short circuit) indicates a failed injector.
• Fuel Injector Coil Resistance (3.0L Duramax Diesel) — expected: 0.2-0.3 Ohms.. Failure: Resistance significantly higher than this range indicates a faulty injector.
• Injector Circuit Continuity — expected: Less than 0.5 - 1.0 Ohms from the ECM connector to the injector connector on both wires.. Failure: A reading of 'OL' (Over Limit) or infinity indicates an open circuit in the harness.
• Injector Balance Test (Pressure Drop) — expected: The pressure drop for each injector should be within 10 kPa (1.5 psi) of the average pressure drop across all cylinders.. Failure: An injector with a pressure drop significantly different from the others is either clogged (low drop) or leaking (high drop).

Scan Tool Commands That Help

• GDS2 (GM Dealer Software): Injector Balance Test — This automated test commands each injector to open for a precise duration and measures the corresponding drop in fuel rail pressure. It's used to identify injectors that are flowing more or less fuel than the others, helping to diagnose a performance issue without physically removing the injectors.
• GDS2 (GM Dealer Software): Cylinder Power Balance — This function allows the technician to disable one cylinder at a time to observe the drop in engine RPM. If disabling cylinder 1 causes little or no change in RPM, it confirms that cylinder is not contributing power, which is the expected result with a P0201 fault.

Wiring & Ground Locations

• Cylinder 1 Injector Control at ECM — On the K20 ECM for L84/L87 V8 engines, the 'Direct Fuel Injector High Voltage Control Cylinder 1' is located at Pin 52 of the X3 connector. The wire color is typically Brown (BN).. This is the specific pin on the engine computer that controls the cylinder 1 injector. Technicians can test for continuity and shorts to ground/voltage at this pin to isolate a wiring fault from a PCM fault.
• G103 — Located at the left rear of the engine compartment on the cowl, often above the brake booster.. This is a major ground point for multiple components, including the Body Control Module (BCM) and the Data Link Connector (DLC). While not the primary engine ground, a poor connection here can cause a wide range of bizarre electrical issues and communication problems that could complicate diagnosis.
• G102 / G104 — Located at the left rear of the engine, often on the cylinder head. G104 specifically serves as the attachment point for a ground strap from the body.. These are critical engine grounds. A loose or corroded ground at these locations can cause unstable sensor readings and intermittent faults for engine components, including the injector circuits.

Real Owner Repair Stories

• gm-trucks.com forum user (2022 Silverado 1500 w/ 3.0L Duramax (Platform mate to Tahoe)) — Check engine light with P0201 and P0301, rough running.
  ❌ Tried (didn't work) Initial dealer diagnosis could not replicate the issue.
  ✅ What actually fixed it The technician found the engine wiring harness was chafing on the A/C line bracket. The wires were repaired and rerouted, which resolved the codes.
• YouTube user 'Gerard Burke' (Not specified, general diagnostic video) — Injector circuit malfunction code.
  ✅ What actually fixed it In the demonstration, a wiring harness connector pin was not fully seated, causing an open circuit. Reseating the connector and ensuring the locking tab was engaged fixed the problem, illustrating the importance of checking simple connections first.

Model Year Variations Within This Range

• 2022 (Refresh models): The introduction of the 'Global B' electrical architecture and a new ECM (E90) on refreshed 2022 models. While the physical causes of P0201 (harness chafing, injector failure) are the same, the diagnostic software (GDS2) and communication protocols are different from the 2021 and early 2022 models. This is a consideration for technicians using scan tools.