P2155 indicates that the engine control module has detected an open circuit in the supply voltage circuit for the fuel injector group D. This means the PCM is not seeing the expected 12 V (or battery‑voltage) signal that should be present when the ignition is on, preventing the injectors in that group from being powered. The fault is usually due to a wiring or connector issue, a blown fuse, or, less commonly, a failure of the injector driver inside the PCM.
A broken wire, chafed insulation, or corrosion in the power feed that runs from the fuse/relay to the injectors in group D prevents voltage from reaching the injectors.
The fuse that protects the injector group D power feed may have opened, cutting off voltage to the entire group.
Poor contact at the plug where the supply wiring meets the injector harness or at the PCM injector‑driver connector can cause an intermittent or permanent open circuit.
Although less common, an injector that has developed an internal open circuit can draw no current and may be interpreted by the PCM as a supply voltage loss if the driver monitors current feedback.
The transistor or driver inside the PCM that switches the supply voltage to group D may have failed. This is uncommon and should be considered only after wiring, fuses, connectors, and injectors have been verified.
No. PCM failure is a rare cause of this code. Most P2155 issues are due to wiring, connectors, fuses, or the injectors themselves. Replacing the PCM without first checking those items often leads to unnecessary expense and does not resolve the problem.
Yes. If the fuse that powers the injector group D supply opens, the PCM will see no voltage on that circuit and set P2155.
Only the injector(s) that test out of specification need replacement. Replacing all injectors is not required unless multiple units fail testing.
A basic OBD‑II scanner, a digital multimeter for voltage and resistance checks, and access to the vehicle’s wiring diagrams for the injector group D supply circuit.