Fuel Injector Group Supply Voltage Low
The P216B code indicates that the powertrain control module (PCM) has detected a low voltage condition in the supply circuit for a group of fuel injectors. This can be caused by a faulty injector driver, damaged wiring, poor electrical connections, or a failing PCM. The low voltage prevents the injectors from opening properly, leading to fuel delivery issues.
1. Most Common Causes
- Open circuit or short to ground in the power supply wiring for injector group 'E'
- Blown fuse or defective injector/FICM power relay
- Faulty Fuel Injector Control Module (FICM)
- Injector(s) in group 'E' with internal short circuit causing bus voltage drop
- Corroded, loose, or damaged connections at the FICM or injector connector
- Internal PCM failure (rare)
2. Symptoms You Will Notice
- Engine misfire or rough idle
- Check Engine Light illuminated
- Poor fuel economy
- Engine hesitation or stalling
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the injector wiring harness and connectors for damage, corrosion, or loose connections.
Step 3: Check the fuse and relay for the injector power supply.
Step 4: Measure voltage at the injector group supply circuit with a multimeter (should be near battery voltage with key on).
Step 5: If voltage is low, trace the circuit back to the PCM to isolate the fault.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause engine misfires, poor performance, and potential damage to the catalytic converter.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on the root cause (e.g., wiring repair, fuse replacement, or PCM replacement).
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.