P216C: Fuel Injector Group E Supply Voltage Circuit High

P216C is the opposite fault of group E: the feed of the cylinder 5 injector carries voltage when it should not. GM tests it while the high-side driver is switched off; if 1 V or less remains between the signal and the controller supply, the line is treated as shorted to power. Its 2016 3.6 LGX V6 and 2018 6.2 LT4 V8 tables need at least 11 V and count 10 failures out of 20 samples at 100 ms, type A with the MIL on the first trip. Typical sources are a chafed wire touching another powered circuit or an injector winding contacting a live conductor; GM's PI0631H lists this code with dozens of others for the Impala harness that wears on the transmission. Because the injector may stay energised, the module cuts it off and cylinder 5 drops out. P216B is the short to ground.

Symptoms

• Check engine lamp on immediately
• Cylinder 5 misfire and rough idle

Most likely causes

• Injector 5 feed chafed against a powered circuit
• High-side driver in the engine control module leaking voltage
• Moisture or corrosion bridging pins in the injector connector

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and wiring of the injector indicated
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Measure the resistance and compare it with the manufacturer's specification
4. Check the control signal with an oscilloscope; on direct injection or diesel engines, leave this to a repair shop because of the high voltages
5. On diesels, check the per-cylinder injection corrections

Good to know

• Repair difficulty: hard
• It can trigger limp mode.
• It affects emissions.

What each character of P216C means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 1: Air and fuel
• 6C: Specific fault in that system

Frequently asked questions

Can I keep driving with code P216C?

Drive as little as possible and go to a repair shop. If you smell fuel or the engine is shaking badly, do not keep driving.

What causes code P216C?

The most common causes are: injector 5 feed chafed against a powered circuit; high-side driver in the engine control module leaking voltage; moisture or corrosion bridging pins in the injector connector.

Related codes

• P216AFuel Injector Group E Supply Voltage Circuit/Open
• P216BFuel Injector Group E Supply Voltage Circuit Low
• P216FFuel Injector Group F Supply Voltage Circuit High
• P0274Cylinder 5 Injector A Circuit High
• P0305Cylinder 5 Misfire Detected
• P2148Fuel Injector Group A Supply Voltage Circuit High

Sources

• gsi.ext.gm.com: 16OBDG05 Engine Diagnostics
• gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
• static.nhtsa.gov: SB 10043310 1492

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.