P2146: Fuel Injector Group A Supply Voltage Circuit/Open
Do not keep driving
Expect a severe misfire or an engine that will not run. Note which cylinders are affected if you are told — a pattern of alternating cylinders rather than adjacent ones points at one shared supply rather than at several failed injectors, and injectors are expensive to replace speculatively. Ask for the module's own supply and grounds to be checked before it is condemned.
What this code means
A fault in the supply feeding the first group of fuel injectors. This code family is unusually informative, and the reason is that injectors are fed in groups rather than individually.
What a group is. The module does not run a separate supply to every injector. It feeds them in sets — typically two or three cylinders sharing one supply and one driver stage — chosen so the cylinders in a group never fire consecutively. So losing a group does not kill adjacent cylinders; it kills alternating ones.
Which makes the misfire pattern diagnostic. A four-cylinder engine that misfires on cylinders 1 and 4 while 2 and 3 are fine is not describing two coincidentally failed injectors. It is describing one supply. The corpus makes this argument repeatedly — one shared thing failing looks exactly like many separate things failing — and here the shared thing is named in the code itself.
The supply is not simply battery voltage. On piezo and high-current solenoid systems, injectors need far more than twelve volts to open quickly enough, so the module generates a boosted rail internally — often many tens of volts — and switches that. This code therefore frequently implicates the module's own boost supply rather than a fuse or a relay, which is a different repair from anything a wiring check will find. It is also why several injectors go silent at once and why the engine may not run at all.
Before concluding the module has failed, the argument from P0882 applies: a module with a marginal supply or a poor ground misbehaves rather than dying, and its internal supplies are among the first things to sag.
Likely causes
Start here
- Faulty fuel injector control module · specialist
- Short circuit in a fuel injector · moderate
- Damaged injector wiring harness · moderate
Less common
- Corroded or loose connector · easy
- Poor module ground connection · moderate
- Low system voltage · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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