P2554 means the powertrain control module has detected an abnormally low voltage on the throttle/fuel inhibit control circuit. This circuit is used to disable engine torque or fuel delivery during events such as traction control activation or limp-home operation. A 'low' reading usually points to a short to ground, high resistance, or a component pulling the circuit voltage below the expected range.
Chafed, corroded, or shorted wiring in the throttle/fuel inhibit circuit is the most common cause of a low-voltage signal.
An internal short or excessive resistance in the inhibit actuator can pull the circuit voltage down.
A blown fuse, poor fuse contact, or degraded ground can cause the circuit to read lower than expected.
A failed output driver inside the control module is possible but uncommon and should only be considered after the circuit and components test good.
You can usually drive briefly, but reduced power, limp mode, or stalling are possible, so diagnosis should be done promptly.
No. Most cases are caused by wiring, connector, or actuator faults; PCM failure is uncommon and should be confirmed last.
It is a safety circuit the PCM can command to cut throttle or fuel delivery; the code indicates the PCM sees that circuit stuck at a low voltage.
Yes, a short to ground on the control or power side of the circuit is a frequent cause of a 'circuit low' code.