P2152 on 2009-2013 Chevrolet Malibu: Injector Group Voltage Circuit Causes and Fixes

What's Unique About the 2009-2013 Chevrolet MALIBU

The 2009-2013 Malibu, particularly models with the 2.4L and 3.6L engines, is specifically known for this problem due to the routing and materials of the fuel injector wiring harness. As documented by GM in Technical Service Bulletin PIP4924C, the harness is prone to rubbing against engine components like the intake plenum, valve cover bolts, or the side of the cylinder head. This consistent point of failure makes a wiring fault a much more common cause than a faulty injector or ECM on this specific vehicle and its platform mates.

Diagnostic Flowchart

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

Generation note: This range covers two Malibu generations. The 2009-2012 models belong to the 7th generation, while the 2013 model year marks the beginning of the 8th generation. The primary cause, a faulty fuel injector wiring harness, is a known issue across both generations within this year range, as confirmed by TSB #PIP4924C and its subsequent revisions which cover models up to 2014.

Symptoms You May Notice

• Check Engine Light is on
• Rough or unstable idle
• Engine misfires, which may feel like a shudder
• Noticeable loss of power and poor acceleration
• Reduced fuel economy
• Engine may stall at low speeds
• Excessive smoke from exhaust

Most Likely Causes

1. Damaged Fuel Injector Wiring Harness 🔴 High Probability → Shop Engine Wiring Harness A General Motors TSB (#PIP4924C and its revisions) was issued specifically for this problem. The harness is known to rub against the intake plenum, valve cover bolts, the fuel line, and on the side of the head under the plenum, causing chafing and wire failure. The wires inside the harness can become brittle from heat and break internally, even without visible external damage.
   How to confirm: Visually inspect the entire fuel injector wiring harness for signs of rubbing, melting, or broken wires. Pay close attention to the specific contact points mentioned in the TSB. A "wiggle test" (wiggling the harness while the engine is idling) may cause the misfire to worsen or change, confirming a wiring issue. If no visible damage is found, use a multimeter to check for continuity from the ECM connector to the injector connector.
   Typical fix: Repair the damaged section of the wire with a new pigtail connector or, for a more robust and recommended solution, replace the entire fuel injector wiring harness. After repair, ensure the harness is properly secured away from sharp edges or hot surfaces.
   Est. part cost: $120-$200 for a full harness, $20-$40 for a pigtail connector.
2. Faulty Fuel Injector ⚪ Low Probability → Shop Fuel Injector
   How to confirm: If the wiring harness is confirmed to be in good condition, test the resistance of the fuel injectors in the affected group with a multimeter. Compare the readings to the manufacturer's specifications. An out-of-spec reading or an open circuit indicates a bad injector.
   Typical fix: Replace the faulty fuel injector. It is often recommended to replace them in sets for balanced performance.
   Est. part cost: $40-$90 per injector
3. Faulty Powertrain Control Module (PCM) ⚪ Low Probability → Shop Engine Control Module (ECM)
   How to confirm: This should be the last resort after all wiring and components have been thoroughly tested and confirmed to be good. Diagnosis requires advanced tools to check the injector driver circuit within the PCM.
   Typical fix: Replace and reprogram the PCM.
   Est. part cost: $200-$500+

Rare But Worth Checking

• Corroded or Loose Connector Pins: The main harness connector at the ECM or the connectors at the fuel injectors can become corroded or loose, causing an intermittent open circuit. This is worth checking while inspecting the harness. Moisture from engine washing can also cause this issue.
• Blown Fuse: In some cases, a blown fuse related to the emissions or ignition systems can cause injector circuit codes. Before extensive wiring diagnosis, it's worth checking the fuses in the under-hood fuse box, specifically those labeled for emissions (often #11 and #47 on some GM models).

Diagnosis Steps

1. Scan the vehicle's computer for all stored trouble codes. Note any other codes present, especially other injector-related codes like P2146, P2149, or P0201-P0206.
2. Carefully and thoroughly inspect the fuel injector wiring harness from the injectors back to the main engine harness. Per TSB PIP4924C, check for areas where it may be rubbing against the intake plenum, valve cover bolts, fuel lines, and the side of the cylinder head.
3. Gently wiggle sections of the harness with the engine idling to see if it affects the engine's performance. A change in idle quality or a stall points directly to a wiring fault.
4. If a damaged section is found, disconnect the battery before repairing.
5. If the harness appears visually intact, disconnect the harness from the ECM and the injectors. Use a multimeter set to continuity to test each wire in the group 'B' circuit for opens (no continuity) or shorts to ground.
6. If wiring and connectors are confirmed to be good, test the resistance of the fuel injectors in the affected group. Compare to manufacturer specs.
7. As a quick check, inspect relevant fuses in the under-hood fuse box before proceeding to more complex diagnostics.
8. Only after ruling out all wiring, connector, and injector faults should a faulty PCM be considered.

Parts You'll Likely Need

• Fuel Injector Wiring Harness (OEM #12604950) — This is the most common failure point for this code on this vehicle, as documented in GM's own service bulletin. This specific part number is listed for 2011-2012 Malibu models with the 2.4L engine. Other years and engines may use a different part number.
  Trusted brands: ACDelco, GM Genuine
  OEM price range: $120-$195
  Aftermarket price range: $100-$160

Related Codes That Often Appear With This One

• P2146 — This code is for 'Fuel Injector Group 'A' Supply Voltage Circuit'. It often appears with P2152 because the same wiring harness that is prone to damage contains the circuits for both injector groups.
• P2149 — Another code for 'Fuel Injector Group 'B' Supply Voltage Circuit' (or sometimes Group 'A' depending on the source), indicating a widespread issue in the injector harness.
• P0201-P0206 — These are specific codes for each injector's circuit (e.g., P0201 for cylinder 1). They can appear alongside P2152, helping to pinpoint which injectors are affected by the voltage supply issue.
• P0300 — This code for 'Random/Multiple Cylinder Misfire' is a direct symptom of an entire bank of injectors not receiving power.

Technical Service Bulletins (TSBs) & Recalls

• PIP4924C: Addresses SES light and misfires with a list of injector-related codes including P2152. The primary recommendation is to inspect the fuel injector wiring harness for chafing or open wires at specific points.
• PIP4924D: A successor to PIP4924C, this bulletin expands the model year range to 2014 and reiterates the same diagnostic procedure, confirming the persistence of the issue.

Platform-Specific Known Issues

• Technical Service Bulletin #PIP4924C (and its successors like PIP4924D) explicitly calls out the fuel injector wiring harness for potential rub-through or internal wire opens on 2009-2013 Malibus. Common chafe points are against the intake plenum, at valve cover bolts, against the fuel line, and on the side of the head under the plenum.
• A YouTube video by a mechanic working on a 2011 Malibu highlights a case where the injector wires became internally broken and soft to the touch near the connector, even without obvious external chafing, causing an open circuit.

Mechanic-Grade Diagnostic Values

• Fuel Injector Coil Resistance — expected: 11 to 14 Ohms. Failure: A resistance reading below 5 Ohms indicates a short, while a very high or infinite (K Ohm) reading indicates an open circuit.
• Voltage Drop on Injector Supply Circuit — expected: Less than 0.5 V. Failure: A voltage difference greater than 0.5V between the ECM supply terminal and the injector connector indicates a high-resistance problem in the wiring.
• Battery/System Voltage — expected: 12.6V at rest, 13.8-14.4V with engine running.. Failure: Sustained low voltage can cause the injector group supply to dip under load, triggering the code. This is not the root cause but can be a contributing factor.

Scan Tool Commands That Help

• GDS2 / Tech 2: Injector Balance Test — This bidirectional test allows a technician to individually fire each injector and measure the corresponding drop in fuel rail pressure. While P2152 is a circuit voltage code, an injector balance test can help confirm if the circuit is electrically capable of firing the injectors, or if one injector is mechanically stuck and drawing incorrect current. A significant deviation in pressure drop for one injector compared to others points to a problem with that specific injector or its circuit.
• GDS2 / High-End Scan Tool: Injector Ckt Short Gnd/Open/Short Volts Test Status — When diagnosing injector codes, a GM service bulletin for a related issue mentions observing these specific status parameters on the scan tool. They should display 'OK' or 'Not Run'. If they show a fault, it confirms the ECM is detecting a specific type of electrical problem (short to ground, open circuit, etc.), which helps narrow down the diagnosis.

Wiring & Ground Locations

• G106 — On the 2.4L engine, this ground is located on the left rear of the engine.. This is a primary ground point for the engine harness. A loose or corroded G106 can cause a variety of electrical issues, including intermittent voltage problems for sensor and actuator circuits like the fuel injectors.
• G107 — On the 2.4L engine, this ground is on the lower left side of the engine.. Similar to G106, this is another critical engine ground. Verifying its integrity is a key step when diagnosing any electrical fault, including injector circuit codes.
• ECM (Engine Control Module) — Located on the left front of the engine compartment, near the battery.. This is the source of the injector control signals and voltage supply. The harness that chafes runs directly from the injectors to the connectors on this module.
• ECM Connector X1 / X2 — These are the main connectors at the ECM where the engine harness attaches.. The voltage supply and control circuits for the fuel injectors pass through these connectors. For example, on some GM models, the Fuel Injector 1 Control is Pin 50 on connector X2. A continuity test for a suspected broken wire would be performed from the injector connector pin back to the corresponding pin at the ECM connector.

OEM Part Supersession History

• Not specified, but likely an earlier revision → 12604950 — This part number is the widely available replacement harness for 2011-2012 2.4L models, likely incorporating improvements to prevent the chafing issues documented in the TSB.