P2555 code meaning
Throttle/Fuel Inhibit A Circuit High
Powertrain system Generic code P25xx codes Check engine light
What P2555 means
P2555 indicates excess voltage on throttle/fuel inhibit circuit A. The same 2005 GM document for the L66 V6 uses two limits depending on key state: more than 10 V while the ignition is on, or more than 4.5 V once it is off, with the fault judged after 4 s. As with its sibling checks, monitoring happens after shutdown, a single time per drive cycle, and the lamp waits until the next trip. A line that should be at a low level reading close to system voltage hints at a short to a battery-fed wire, a relay stuck closed or a lost ground on the receiving side. P2554 is the low-voltage counterpart, P2553 the relay function check and P2552 the general circuit fault. CARB requires makers to monitor electronic inputs of this kind for out-of-range values. Effects can include limited throttle or reduced power.
P2555 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2555
- Check engine light on the next trip
- Limited throttle opening or reduced power
Common causes of P2555
- Most likelyInhibit circuit shorted to a battery-fed wire
- PossibleInhibit relay stuck closed
- Less likelyMissing ground on the receiving side
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Throttle inhibit aWiring harness
What each part of P2555 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 55 | The exact fault in that area. |
What to do next
- Note P2555 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2555
What does P2555 mean?
P2555 means "Throttle/Fuel Inhibit A Circuit High". P2555 indicates excess voltage on throttle/fuel inhibit circuit A. It is a generic code, so it means the same on every make.
Is it safe to drive with P2555?
Drive gently and only to a workshop. With P2555 the car can go into limp mode (reduced power) to protect itself.
Will P2555 fail an emissions test?
Yes, it can. P2555 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2555 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P2555 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.