P2552

Code

Generic P — Powertrain

Throttle/Fuel Inhibit A Circuit

Brand: Generic

Type: P — Powertrain

Views: UK: 36 EN: 29 RU: 28

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Page language: EN

Causes

Open or shorted wiring/harness in the inhibit A circuit
Corroded, loose or damaged connectors or pins
Faulty throttle actuator, throttle body or fuel inhibit solenoid/module
Blown fuse or defective relay supplying the circuit
Poor or intermittent ground connection
Faulty PCM/ECM or throttle/fuel control module

Symptoms

Malfunction Indicator Lamp (MIL) on
Reduced engine power / limp-home mode
Poor or no throttle response / reduced acceleration
No-start or difficulty starting on systems that use fuel inhibit
Intermittent loss of driveability or unexpected engine shutdown

What to check

Record freeze-frame and live data with a scan tool; note when code sets
Visual inspection of wiring, connectors, and components on the inhibit A circuit
Check related fuses and relays for continuity and correct operation
Backprobe connector(s) while operating to monitor voltage and ground
Wiggle test wiring harness while observing live data for intermittent faults
Measure continuity and resistance between PCM, component, and ground

Signal parameters

Control signal typically a switched 12 V feed, ground reference, or low-voltage control (0–5 V) depending on design
Open circuit: no voltage where a feed is expected; component not energizing
Short to ground: near 0 V at feed line under conditions when voltage is expected
Short to battery: near battery voltage at sensor/control line when it should be low or pulsed
High resistance: voltage drop under load or erratic signal when component is commanded

Diagnostic algorithm

Retrieve all stored codes and freeze-frame data; note whether other throttle or fuel codes exist.
Clear the code and attempt to reproduce; monitor live data for throttle position, inhibit status, and related channels.
Perform a visual inspection of the throttle body, fuel inhibit solenoid/module and their connectors for corrosion, damage, or loose pins.
Verify power and ground at the component connector with the ignition ON and while commanding the inhibit function (use scan tool if available).
Check related fuses and relays; replace if suspect and see if code returns.
Perform continuity and resistance checks between component connector and PCM terminals; look for opens, shorts to ground, or short to battery.
If intermittent, perform wiggle tests on harness and harness routing while monitoring live data to identify breaks under movement.
If wiring and connectors test good, test or bench-check the throttle actuator or inhibit module per manufacturer procedure; substitute known-good unit if available.
If component substitution does not resolve the fault, inspect and test the PCM/ECM outputs and grounds; consult manufacturer wiring diagrams for pinouts and reference values.
After repair, clear codes and road-test to confirm the circuit remains stable and no new codes set.

Likely causes

Connector corrosion at throttle body or inhibit solenoid
Broken/chafed wire that opens under engine movement
Short to battery or short to ground at harness near component
Failed throttle actuator control circuitry (internal to throttle body)
Blown fuse or stuck relay feeding the circuit

Fault status

⚠️ Status

Powertrain control module detected a fault in the Throttle/Fuel Inhibit A electrical circuit (open, short, or incorrect voltage). The fault is stored and will illuminate the MIL; driving may be limited until the condition is corrected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5-3 hours