Symptom
Engine cuts out without warning
The engine stops instantly and completely with no preceding roughness, taking power steering and brake assist with it. At speed this is genuinely hazardous, and an intermittent crank position signal is a leading cause.
Also described as: cuts out suddenly, dies without warning, engine just stops, sudden stall, shuts off while driving, loses power completely, ناگهانی خاموش میشود, بدون هشدار خاموش میشه, se apaga sin avisar, se apaga de repente, se apaga mientras conduzco, تطفي بدون سابق إنذار, تفصل فجأة أثناء القيادة, تطفي وأنا أسوق
Some causes mean you should stop driving
14 of the 47 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
Treat this as a safety matter rather than a driveability one. When the engine stops at speed the power steering assistance and the brake servo vacuum go with it, so the car becomes heavy to steer and needs far more pedal effort exactly when it is still travelling at speed.
An instant, complete cut with no roughness beforehand is a different fault from a stall, and the absence of warning is the diagnostic content. An engine that is running badly and then stops has been struggling with something — fuel, air, a cylinder. An engine that stops as though a switch was thrown has lost something it cannot run a single revolution without: the crank position signal, the ignition supply, or a main relay's output.
The crank position sensor is the leading cause and it fails in a characteristic way. The management will not fire injectors or coils without it, so its loss is instantaneous and total; and the failure is frequently heat-related, so the car cuts out after twenty minutes, refuses to restart, and then starts perfectly once it has stood. A workshop test on a cold car finds nothing, which is why this fault has a reputation for being untraceable.
The other population is supply, and it is worth checking with a wiggle rather than a meter: an ignition switch whose contacts are worn, a main relay with tired solder joints, or an earth strap. All three produce an instant cut and all three are intermittent by nature.
Log live engine speed continuously if it can be reproduced. A signal that disappears before the engine stops names the sensor; one that disappears with the engine points at supply. That distinction is difficult to reason about afterwards and trivial to see on a recording.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Instant cut, no roughness first, often after twenty minutes of running | Crank position sensor failing when hot — the management cannot fire injectors or coils without it | Log live engine speed continuously and look for the signal disappearing before the engine stops. Reproduce hot; a cold test proves nothing. | Renew the sensor. Inspect the reluctor and the connector before fitting, because a damaged reluctor gives the same result. |
| Cut coincides with a bump, a turn, or the key being nudged | Supply interrupted — worn ignition switch contacts, a tired main relay, or a failing earth | Wiggle-test the switch, relay and harness while monitoring supply voltage at the management. Tapping the relay while it runs is a crude but effective test. | Renew the switch or relay, or repair the earth. Re-solder is not a repair on a relay that has already failed once. |
| Cuts out and will not restart until it has stood and cooled | A heat-dependent failure — the sensor above, an ignition module, or a fuel pump drawing more as it warms | Test at temperature rather than in the workshop. Measure fuel pressure immediately after a cut, before anything cools. | Renew what the hot test condemns rather than what the cold test passes. |
| Cuts out with the immobiliser or security lamp behaving oddly | Immobiliser authorisation being withdrawn — a failing transponder or reader coil | Watch the security lamp at the moment of the cut, and try the spare key over a period. Read immobiliser codes rather than engine ones. | Renew the transponder or repair the reader coil, then re-learn the key. |
| Cuts out on hard cornering or braking, tank below a quarter | Fuel starvation as the pickup uncovers — often a failed transfer pump in a two-part tank | Note the fuel level and the manoeuvre each time. If filling the tank cures it completely, that is close to a diagnosis on its own. | Renew the transfer pump or repair the pickup. The main pump usually tests perfectly, which is why it gets replaced first and changes nothing. |
| Diesel, instant cut with the engine warm and no restart | Loss of rail pressure — air ingress, a failing high-pressure pump, or excessive injector leak-off | Watch live rail pressure through the cut and during the failed restart. Measure injector leak-off across the set. | Repair the air leak or the leaking injector; the pump only once those are excluded. |
-
Instant cut, no roughness first, often after twenty minutes of running
- Likely cause
- Crank position sensor failing when hot — the management cannot fire injectors or coils without it
- How to confirm it
- Log live engine speed continuously and look for the signal disappearing before the engine stops. Reproduce hot; a cold test proves nothing.
- What fixes it
- Renew the sensor. Inspect the reluctor and the connector before fitting, because a damaged reluctor gives the same result.
-
Cut coincides with a bump, a turn, or the key being nudged
- Likely cause
- Supply interrupted — worn ignition switch contacts, a tired main relay, or a failing earth
- How to confirm it
- Wiggle-test the switch, relay and harness while monitoring supply voltage at the management. Tapping the relay while it runs is a crude but effective test.
- What fixes it
- Renew the switch or relay, or repair the earth. Re-solder is not a repair on a relay that has already failed once.
-
Cuts out and will not restart until it has stood and cooled
- Likely cause
- A heat-dependent failure — the sensor above, an ignition module, or a fuel pump drawing more as it warms
- How to confirm it
- Test at temperature rather than in the workshop. Measure fuel pressure immediately after a cut, before anything cools.
- What fixes it
- Renew what the hot test condemns rather than what the cold test passes.
-
Cuts out with the immobiliser or security lamp behaving oddly
- Likely cause
- Immobiliser authorisation being withdrawn — a failing transponder or reader coil
- How to confirm it
- Watch the security lamp at the moment of the cut, and try the spare key over a period. Read immobiliser codes rather than engine ones.
- What fixes it
- Renew the transponder or repair the reader coil, then re-learn the key.
-
Cuts out on hard cornering or braking, tank below a quarter
- Likely cause
- Fuel starvation as the pickup uncovers — often a failed transfer pump in a two-part tank
- How to confirm it
- Note the fuel level and the manoeuvre each time. If filling the tank cures it completely, that is close to a diagnosis on its own.
- What fixes it
- Renew the transfer pump or repair the pickup. The main pump usually tests perfectly, which is why it gets replaced first and changes nothing.
-
Diesel, instant cut with the engine warm and no restart
- Likely cause
- Loss of rail pressure — air ingress, a failing high-pressure pump, or excessive injector leak-off
- How to confirm it
- Watch live rail pressure through the cut and during the failed restart. Measure injector leak-off across the set.
- What fixes it
- Repair the air leak or the leaking injector; the pump only once those are excluded.
Codes that produce this symptom (47)
Listed with the codes that most typically present this way first — the likeliest place to start.
- P025C Fuel Pump Module A Control Circuit Low Typical of this code Stop driving High
- P0339 Crankshaft Position Sensor A Circuit Intermittent Typical of this code Stop driving Critical
- P062A Fuel Pump A Control Circuit Range/Performance Typical of this code High
- P2105 Throttle Actuator Control System — Forced Engine Shutdown Typical of this code Stop driving Critical
- P2111 Throttle Actuator A Control System — Stuck Open Typical of this code Stop driving Critical
- P2509 Engine Control Module Power Input Signal Intermittent Typical of this code High
- P2511 Engine Control Module Power Relay Sense Circuit Intermittent Typical of this code High
- P2530 Ignition Switch Run Position Circuit Typical of this code High
- P2531 Ignition Switch Run Position Circuit Low Typical of this code High
- P2553 Throttle/Fuel Inhibit A Circuit Range/Performance Typical of this code High
- P2632 Fuel Pump B Control Circuit Open Typical of this code High
- U0100 Lost Communication With Engine Control Module A Typical of this code Stop driving High
- U0105 Lost Communication With Fuel Injector Control Module Typical of this code Stop driving High
- U0107 Lost Communication With Throttle Actuator A Control Module Typical of this code Stop driving High
- U0109 Lost Communication With Fuel Pump Control Module A Typical of this code Stop driving High
- P008A Low Pressure Fuel System Pressure - Too Low High
- P016F Closed Loop Fuel Pressure Control At Limit - Pressure Too Low High
- P025A Fuel Pump Module A Control Circuit/Open Stop driving High
- P0604 Internal Control Module Random Access Memory (RAM) Error High
- P0606 Engine Control Module Processor High
- P060C Internal Control Module Main Processor Performance Stop driving High
- P0627 Fuel Pump A Control Circuit Open High
- P0629 Fuel Pump A Control Circuit High High
- P0641 Sensor Reference Voltage A Circuit Open High
- P0657 Actuator Supply Voltage A Circuit Open 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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