The P2157: Fuel Injector Group ‘D’ Supply Voltage Circuit High refers to a condition where the voltage in the supply circuit for fuel injector group ‘D’ is higher than expected. This can lead to improper fuel injection, causing performance issues such as misfires, increased fuel consumption, and poor engine efficiency. The problem could stem from faulty wiring, malfunctioning fuel injectors, or power supply issues.
P2157 – Quick Overview
Code | Information |
---|---|
Meaning | P2157: Fuel Injector Group ‘D’ Supply Voltage Circuit High |
Is it serious? | Yes, it can cause engine performance issues such as misfires and inefficient fuel usage. |
Possible causes | – High voltage in the fuel injector group ‘D’ supply circuit – Faulty fuel injector group ‘D’ – Wiring issues or power supply problems |
How to diagnose? | – Measure voltage in the fuel injector group ‘D’ supply circuit – Test the fuel injector group ‘D’ – Inspect wiring and connections for faults |
P2157 Meaning
The P2157 code indicates that the voltage supplied to fuel injector group ‘D’ is higher than the manufacturer’s specified range. This excessive voltage can cause the injectors to deliver too much fuel, leading to engine performance problems like rough running, misfires, and inefficient fuel consumption. The issue could be caused by wiring faults, a malfunctioning injector, or a problem with the power supply.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for any additional related codes that could give more insight into the issue with the fuel injector group or the power supply. | OBD-II Scanner |
Measure Voltage in the Supply Circuit | Use a multimeter to measure the voltage at the fuel injectors in group ‘D’. Compare the readings with the manufacturer’s specifications to confirm whether the voltage is higher than required. | Multimeter |
Test the Fuel Injectors | Use a diagnostic tool to test the performance of the fuel injectors in group ‘D’. Replace any injectors that are not operating within proper specifications. | Diagnostic Tool, Multimeter |
Inspect Wiring and Connectors | Visually inspect the wiring and connectors for fuel injector group ‘D’ for signs of damage, loose connections, or corrosion. Repair or replace any damaged wiring as necessary. | Flashlight, Multimeter |
Check Power Supply Components | Inspect the power supply components (fuse, relay, and ECU) that supply voltage to fuel injector group ‘D’. Ensure they are functioning correctly and not causing overvoltage. | Multimeter, Wiring Diagram |
Check for Shorts or Electrical Faults | Use a multimeter to check for shorts, open circuits, or other electrical faults in the wiring leading to the injectors in group ‘D’. Repair any faults causing excessive voltage. | Multimeter, Wiring Diagram |
Clear the Code and Test Drive | After completing repairs or adjustments, clear the code using an OBD-II scanner and take the vehicle for a test drive to ensure that the issue is resolved. | OBD-II Scanner |
Recheck for Codes | After the test drive, re-scan the vehicle to ensure the P2157 code has not returned. | OBD-II Scanner |
Free PDF: How to choose OBD2 scanner

I’ve made you a free PDF to choose the OBD2 scanner in 5 minutes.
✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
Just tell me where to send it.

Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)