Symptom
Engine will not rev above idle
The engine runs and idles, sometimes faster than normal, but pressing the accelerator does nothing. On a drive-by-wire vehicle this is usually the throttle sitting on its spring default — the position it rests in when the module stops driving the motor, deliberately left slightly open so the engine keeps running rather than stopping dead. So the symptom is the fail-safe working rather than the engine failing. Distinct from a general loss of power, where the engine revs but will not pull; here it will not rev at all.
Also described as: won't rev, no throttle response, accelerator does nothing, stuck at idle, revs stuck, pedal not working, engine only idles, limp mode no power, gas pedal does nothing, دور موتور بالا نمیرود, گاز نمیگیرد, no sube de revoluciones, no pasa de ralenti, motor no acelera, no pasa de marcha minima, الدورات لا تزيد, لا تتجاوز الرلنتي, المحرك لا يستجيب للبنزين
Some causes mean you should stop driving
20 of the 29 codes that produce this symptom indicate a fault where continuing to drive risks damage or is unsafe. If the symptom is sudden or severe, treat it as one of those until a scan says otherwise.
What this usually means
The engine running perfectly well while completely ignoring the accelerator is a specific finding, not a severe version of losing power. It says combustion is fine and the request is not arriving — which on any drive-by-wire car points first at the throttle system's own fail-safe rather than at a failure.
There is no cable. The pedal is a sensor, the throttle is a motor, and a module decides what one means for the other. When the module stops driving that motor, a spring returns the throttle plate to a default position that is deliberately slightly open — enough to keep the engine running rather than have it stop dead in traffic. So an engine that idles, sometimes a little fast, and will not respond at all is usually the fail-safe doing exactly what it was designed to do. The symptom is the protection, not the fault.
Two pedal sensors exist so the module can cross-check them, and when they disagree it believes neither. Russian references describe the common high-mileage version: the resistive track wears through, so the signal drops out at one point in the sweep. That dropout is invisible to a static multimeter reading and obvious on an oscilloscope, which is the practical reason this fault gets misdiagnosed.
The population that has nothing to do with the throttle is small but worth keeping in view: a completely blocked exhaust will not let an engine rev however wide the throttle opens, and severe fuel starvation does the same. Both are distinguishable in a minute — a blocked exhaust shows immediately on a backpressure gauge, and fuel starvation shows on a pressure gauge under load.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Idles normally or slightly fast, pedal does nothing at all | Electronic throttle in its spring default — the module has stopped driving the motor | Read throttle and pedal position live: a commanded opening that the actual position does not follow confirms it. Stored throttle or pedal codes usually name the circuit. | Diagnose the named circuit. The throttle body is not automatically the answer — the fault may be the pedal or the wiring between them. |
| Pedal sensor tracks disagree, or one drops out mid-sweep | Worn resistive track in the pedal or throttle sensor — the classic high-mileage failure | Sweep the pedal slowly while watching both tracks on an oscilloscope. A momentary dropout is invisible to a multimeter, which is why it gets missed. | Renew the pedal assembly. Both tracks usually live in one unit, so it is a single part. |
| Throttle plate does not move when commanded | Throttle motor, its drive, or a plate seized in its bore with carbon | Command the throttle on a scan tool and watch the plate, or feel for movement. Check the motor's supply before condemning the body. | Clean the body if carbon is binding the plate, renew it if the motor is dead. Re-learn the throttle adaptation afterwards. |
| Revs a little then falls back, with a strangled note | Exhaust completely blocked — a collapsed catalyst monolith is the usual culprit | Backpressure gauge: under roughly 1.5 psi at idle and about 3 psi at 2,000 rpm on most engines. A blocked exhaust will be far outside that and rises fast with any attempt to rev. | Renew the restricted section and repair whatever destroyed it — usually an old misfire. |
| Revs briefly then dies back under any load | Severe fuel starvation — a blocked filter, a failing pump, or a collapsing supply line | Gauge fuel pressure while the engine is asked to rev, not at idle. The reading falling away as demand rises is the finding. | Renew the filter or pump on the loaded measurement. Check the tank for contamination while it is apart. |
| Only on a manual, only with the clutch up | Not a fault — a clutch or gear-selection interlock, or a transmission-imposed limit | Reproduce in neutral with the clutch down. Behaviour that changes with the clutch is not a throttle fault. | Diagnose the interlock or transmission input rather than the engine. |
-
Idles normally or slightly fast, pedal does nothing at all
- Likely cause
- Electronic throttle in its spring default — the module has stopped driving the motor
- How to confirm it
- Read throttle and pedal position live: a commanded opening that the actual position does not follow confirms it. Stored throttle or pedal codes usually name the circuit.
- What fixes it
- Diagnose the named circuit. The throttle body is not automatically the answer — the fault may be the pedal or the wiring between them.
-
Pedal sensor tracks disagree, or one drops out mid-sweep
- Likely cause
- Worn resistive track in the pedal or throttle sensor — the classic high-mileage failure
- How to confirm it
- Sweep the pedal slowly while watching both tracks on an oscilloscope. A momentary dropout is invisible to a multimeter, which is why it gets missed.
- What fixes it
- Renew the pedal assembly. Both tracks usually live in one unit, so it is a single part.
-
Throttle plate does not move when commanded
- Likely cause
- Throttle motor, its drive, or a plate seized in its bore with carbon
- How to confirm it
- Command the throttle on a scan tool and watch the plate, or feel for movement. Check the motor's supply before condemning the body.
- What fixes it
- Clean the body if carbon is binding the plate, renew it if the motor is dead. Re-learn the throttle adaptation afterwards.
-
Revs a little then falls back, with a strangled note
- Likely cause
- Exhaust completely blocked — a collapsed catalyst monolith is the usual culprit
- How to confirm it
- Backpressure gauge: under roughly 1.5 psi at idle and about 3 psi at 2,000 rpm on most engines. A blocked exhaust will be far outside that and rises fast with any attempt to rev.
- What fixes it
- Renew the restricted section and repair whatever destroyed it — usually an old misfire.
-
Revs briefly then dies back under any load
- Likely cause
- Severe fuel starvation — a blocked filter, a failing pump, or a collapsing supply line
- How to confirm it
- Gauge fuel pressure while the engine is asked to rev, not at idle. The reading falling away as demand rises is the finding.
- What fixes it
- Renew the filter or pump on the loaded measurement. Check the tank for contamination while it is apart.
-
Only on a manual, only with the clutch up
- Likely cause
- Not a fault — a clutch or gear-selection interlock, or a transmission-imposed limit
- How to confirm it
- Reproduce in neutral with the clutch down. Behaviour that changes with the clutch is not a throttle fault.
- What fixes it
- Diagnose the interlock or transmission input rather than the engine.
Codes that produce this symptom (29)
Listed with the codes that most typically present this way first — the likeliest place to start.
- P061B Internal Control Module Torque Calculation Performance Typical of this code Stop driving High
- P2100 Throttle Actuator A Control Motor Circuit/Open Typical of this code Stop driving High
- P2102 Throttle Actuator A Control Motor Circuit Low Typical of this code Stop driving High
- P2103 Throttle Actuator A Control Motor Circuit High Typical of this code Stop driving High
- P2104 Throttle Actuator Control System — Forced Idle Typical of this code Stop driving High
- P2107 Throttle Actuator A Control Module Processor Typical of this code Stop driving High
- P2112 Throttle Actuator A Control System — Stuck Closed Typical of this code Stop driving High
- P2120 Throttle/Pedal Position Sensor/Switch D Circuit Typical of this code Stop driving High
- P2122 Throttle/Pedal Position Sensor/Switch D Circuit Low Typical of this code Stop driving High
- P2123 Throttle/Pedal Position Sensor/Switch D Circuit High Typical of this code Stop driving High
- P2125 Throttle/Pedal Position Sensor/Switch E Circuit Typical of this code Stop driving High
- P2127 Throttle/Pedal Position Sensor/Switch E Circuit Low Typical of this code Stop driving High
- P2128 Throttle/Pedal Position Sensor/Switch E Circuit High Typical of this code Stop driving High
- P2135 Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation Typical of this code Stop driving High
- P2136 Throttle/Pedal Position Sensor/Switch A/C Voltage Correlation Typical of this code Stop driving High
- P2137 Throttle/Pedal Position Sensor/Switch B/C Voltage Correlation Typical of this code Stop driving High
- P2138 Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation Typical of this code Stop driving High
- P2139 Throttle/Pedal Position Sensor/Switch D/F Voltage Correlation Typical of this code Stop driving High
- P2140 Throttle/Pedal Position Sensor/Switch E/F Voltage Correlation Typical of this code Stop driving High
- U0107 Lost Communication With Throttle Actuator A Control Module Typical of this code Stop driving High
- U0408 Invalid Data Received From Throttle Actuator A Control Module Typical of this code High
- P064B PTO Control Module Moderate
- P06A3 Sensor Reference Voltage D Circuit/Open High
- P253D PTO Sense Circuit High Moderate
- P2546 Torque Management Request Input Signal A Circuit Low High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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