What Does P2151 Mean?
The PCM has detected excessive voltage in the fuel injector group B power supply circuit. This condition can damage injectors and prevent proper fuel delivery control.
Safety Warning
High voltage can damage fuel injectors and may cause fuel delivery issues leading to stalling. Fire risk exists if wiring insulation has melted from excessive current.
Common Causes
35%
Faulty PCM voltage regulator or injector driver circuit malfunction
30%
Shorted wiring causing voltage spike from another circuit
20%
Defective fuel injector relay stuck or providing excessive voltage
15%
Charging system malfunction causing overvoltage condition
Diagnostic Steps
1
Step 1: Test battery and charging system voltage to rule out overvoltage from alternator (should be 13.5-14.5V)
2
Step 2: Measure voltage at injector group B connector with key on and engine running
3
Step 3: Inspect wiring harness for evidence of shorts to power from other circuits
4
Step 4: Test injector relay output voltage and check for proper operation
5
Step 5: Monitor PCM voltage output to injector circuit using scan tool data if available
Estimated Repair Cost
$100 - $1,200
Parts + labor, varies by vehicle and location
The PCM has detected excessive voltage in the fuel injector group B power supply circuit. This condition can damage injectors and prevent proper fuel delivery control.
The most common cause of P2151 (Fuel Injector Group "B" Supply Voltage Circuit High) is: Faulty PCM voltage regulator or injector driver circuit malfunction
Typical repair costs for P2151 range from $100 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
High voltage can damage fuel injectors and may cause fuel delivery issues leading to stalling. Fire risk exists if wiring insulation has melted from excessive current.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2151 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
