Throttle/Fuel Inhibit Circuit High
The P2555 code means the vehicle's onboard diagnostic system has detected: Throttle/Fuel Inhibit Circuit High. This is a critical severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $800 (parts and labor)
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What Are the Symptoms of P2555?
- Inhibit system cannot activate when needed
- Safety override disabled
- Check engine light on
- Vehicle may operate normally until fault condition occurs
What Causes P2555? (Most Likely First)
- Short to voltage in inhibit circuit Very High
- Inhibit relay contacts welded closed High
- Wiring harness damage providing constant power Moderate
- ECM inhibit driver output stuck high Low
Can I Still Drive with P2555?
Short distances only. P2555 is rated critical severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
Is P2555 dangerous even though the car drives fine?
Yes. The inhibit circuit is a safety system. If it cannot activate when needed, the ECM cannot limit throttle during a detected fault, potentially allowing unintended acceleration.
What happens if the inhibit circuit cannot engage?
If a throttle fault occurs, the ECM would normally cut throttle and fuel. With P2555, this safety response may not function, creating a potential safety hazard.
Should I drive with P2555?
Only short distances at low speeds to reach a repair shop. The safety override system is compromised and should be repaired as soon as possible.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P2555?
-
Check inhibit circuit for constant voltage condition
-
Test inhibit relay for welded contacts
-
Inspect wiring for short to power source
-
Verify ECM can command inhibit circuit low
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Which Vehicles Commonly Get P2555?
- 2010-2020 Toyota Camry
- 2012-2019 Nissan Maxima
- 2008-2018 Ford Fusion
- 2011-2020 Chevrolet Impala
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