What Does P2156 Mean?
The powertrain control module (PCM) has detected that the voltage supply to fuel injector group D is lower than expected. This indicates a problem in the power supply circuit feeding the fourth bank of injectors.
Common Causes
35%
Damaged or corroded wiring/connectors in injector group D power supply circuit
25%
Faulty fuel injector driver circuit in PCM
20%
Failed injector power relay or fuse for group D
15%
Short to ground in injector group D circuit
5%
One or more failed injectors in group D creating excessive current draw
Diagnostic Steps
1
Step 1: Visually inspect all wiring and connectors to injector group D for damage, corrosion, or loose connections
2
Step 2: Check injector group D fuse and relay; test for proper voltage at relay output
3
Step 3: Measure voltage at injector group D supply wire with key on, engine off (should be battery voltage)
4
Step 4: Perform resistance test on each injector in group D to identify shorts or open circuits
5
Step 5: Use oscilloscope to monitor injector driver circuit during operation if all previous tests pass
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
The powertrain control module (PCM) has detected that the voltage supply to fuel injector group D is lower than expected. This indicates a problem in the power supply circuit feeding the fourth bank of injectors.
The most common cause of P2156 (Fuel Injector Group "D" Supply Voltage Circuit Low) is: Damaged or corroded wiring/connectors in injector group D power supply circuit
Typical repair costs for P2156 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may run rough, misfire, or experience reduced power. Generally safe to drive short distances but repair soon to prevent catalytic converter damage.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2156 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System
Difficulty
Type
Generic (SAE)
Recommended Tools
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