Symptom
Problems started after driving through water
A flood, a ford, a deep puddle or a jet wash, and the car has not been right since. Water rarely announces itself where it entered. It runs along a loom to the lowest connector and sits there, so the fault appears at a part that never got wet, sometimes days later and often only in the damp. Connectors under the bumper, inside the doors and beneath the seats are where it collects. The one thing worth saying plainly is about the engine itself: an engine that drew water in through the air intake can be damaged beyond repair by a single attempt to restart it, so if it stopped in the water rather than after it, do not turn the key.
Also described as: after driving through a flood, drove through a flood, drove through water, went through deep water, after a jet wash, since it got wet, drove through a puddle, water got in, بعد از رد شدن از اب, بعد از سیل و اب گرفتگی, despues de pasar charco, pasar por agua, despues de inundacion, entro agua motor, بعد ما دخلت بركة ماء, المشكلة بعد المطر والمياه, بعد ما غرقت بالماء
Some causes mean you should stop driving
3 of the 40 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 one thing worth saying plainly first: an engine that drew water in through the air intake can be destroyed by a single attempt to restart it. If it stopped in the water rather than after it, do not turn the key. Water does not compress, so a cylinder that has taken some in bends a connecting rod rather than firing.
Water rarely announces itself where it entered. It runs along a loom to the lowest connector and sits there, so the fault appears at a part that never got wet — sometimes days later, and often only in the damp. Connectors under the bumper, inside the doors and beneath the seats are where it collects.
That is why chasing the symptom fails and following the harness works. From the affected connector, trace upward looking for the entry: a grommet, a chafed section, a blocked drain that overflowed into a loom channel. Sealing the connector without finding the entry means it fills again.
Expect several faults rather than one, and expect them staggered. Corrosion takes time to develop into a bad connection, so a car that seemed fine for a fortnight after a flood is not in the clear.
Check the things water damages quietly. The air filter — a wet one tells you how close the intake came. The oil, for a milky emulsion that means water got into the crankcase. The differentials and gearboxes, which breathe through vents that can draw water in as hot units cool in cold water. And the wheel bearings and brakes, which do not fail immediately but do fail early.
A jet wash belongs in the same brief, because pressure gets water past seals that ordinary rain never challenges.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Engine stopped while in the water and will not restart | Possible hydraulic lock — water drawn into a cylinder, which does not compress | Do not crank it. Remove the air filter and look: a soaked filter is the evidence. Removing the plugs or injectors and turning it by hand is the safe check. | Recover the vehicle. Assess before any attempt to start; one crank is what turns a wet engine into a bent rod. |
| Electrical faults days or weeks after the event | Water sitting in a low connector, with corrosion developing into a bad connection over time | Inspect the lowest connectors in the affected circuits — under the bumper, in the doors, under the seats. Green corrosion is unmistakable. | Dry, clean and seal, and repair the route that let it in. Expect more than one over the following months. |
| The faulty component plainly never got wet | Water ran along the loom from a higher entry point and collected at the low point | Trace the harness upward from the affected connector rather than inspecting around the symptom. | Seal the entry, not just the connector. Sealing the low point alone means it fills again from the same place. |
| Milky residue on the dipstick or the oil filler cap | Water in the crankcase — through the intake, the breather, or a submerged dipstick tube | Check the oil itself rather than only the cap, which can show condensation innocently. A milky dipstick is the real finding. | Change the oil and filter immediately, run briefly, and check again. Water in oil destroys bearings quietly. |
| Gearbox or differential noisy or rough in the months afterwards | Water drawn in through a breather as a hot unit cooled in cold water | Check the oil for emulsion at each breather-equipped unit. This is the damage nobody checks for and it appears late. | Drain and refill with the correct specification. Do this proactively after a deep-water event rather than waiting for noise. |
| Followed a jet wash rather than a flood | Pressure forcing water past seals that ordinary rain never challenges | Establish the timing. Lances used near the engine bay, wheel arches or under-bumper connectors are the usual trigger. | Dry and reseal. Advise keeping the lance away from connectors and seals, or it recurs. |
-
Engine stopped while in the water and will not restart
- Likely cause
- Possible hydraulic lock — water drawn into a cylinder, which does not compress
- How to confirm it
- Do not crank it. Remove the air filter and look: a soaked filter is the evidence. Removing the plugs or injectors and turning it by hand is the safe check.
- What fixes it
- Recover the vehicle. Assess before any attempt to start; one crank is what turns a wet engine into a bent rod.
-
Electrical faults days or weeks after the event
- Likely cause
- Water sitting in a low connector, with corrosion developing into a bad connection over time
- How to confirm it
- Inspect the lowest connectors in the affected circuits — under the bumper, in the doors, under the seats. Green corrosion is unmistakable.
- What fixes it
- Dry, clean and seal, and repair the route that let it in. Expect more than one over the following months.
-
The faulty component plainly never got wet
- Likely cause
- Water ran along the loom from a higher entry point and collected at the low point
- How to confirm it
- Trace the harness upward from the affected connector rather than inspecting around the symptom.
- What fixes it
- Seal the entry, not just the connector. Sealing the low point alone means it fills again from the same place.
-
Milky residue on the dipstick or the oil filler cap
- Likely cause
- Water in the crankcase — through the intake, the breather, or a submerged dipstick tube
- How to confirm it
- Check the oil itself rather than only the cap, which can show condensation innocently. A milky dipstick is the real finding.
- What fixes it
- Change the oil and filter immediately, run briefly, and check again. Water in oil destroys bearings quietly.
-
Gearbox or differential noisy or rough in the months afterwards
- Likely cause
- Water drawn in through a breather as a hot unit cooled in cold water
- How to confirm it
- Check the oil for emulsion at each breather-equipped unit. This is the damage nobody checks for and it appears late.
- What fixes it
- Drain and refill with the correct specification. Do this proactively after a deep-water event rather than waiting for noise.
-
Followed a jet wash rather than a flood
- Likely cause
- Pressure forcing water past seals that ordinary rain never challenges
- How to confirm it
- Establish the timing. Lances used near the engine bay, wheel arches or under-bumper connectors are the usual trigger.
- What fixes it
- Dry and reseal. Advise keeping the lance away from connectors and seals, or it recurs.
Codes that produce this symptom (40)
Listed with the codes that most typically present this way first — the likeliest place to start.
- P012A Turbocharger/Supercharger Inlet Pressure Sensor A Circuit Typical of this code Moderate
- P018D Fuel Pressure Sensor B Circuit High Typical of this code Moderate
- P0448 Evaporative Emission System Vent Control Circuit Shorted Typical of this code Low
- P04CB Fuel Fill Door Open Request Sensor/Switch Circuit High Typical of this code Low
- P0564 Cruise Control Multi-Function Input A Circuit Typical of this code Low
- P0576 Cruise Control Input Circuit Low Typical of this code Low
- P0580 Cruise Control Multi-Function Input A Circuit Low Typical of this code Low
- P05F8 Reductant Heater Control Module Performance Typical of this code Moderate
- P0606 Engine Control Module Processor Typical of this code High
- P060C Internal Control Module Main Processor Performance Typical of this code Stop driving High
- P0684 Glow Plug Control Module 1 to Powertrain Control Module Communication Circuit Range/Performance Typical of this code Moderate
- P0AA6 Hybrid/EV Battery Voltage System Isolation Fault Typical of this code High
- P0D00 Control Pilot Charging Ventilation Switch Circuit/Open Typical of this code High
- P0DED Pedestrian Alert Control Module Circuit/Open Typical of this code Moderate
- P0DEE Pedestrian Alert Control Module Circuit Low Typical of this code Moderate
- P0DEF Pedestrian Alert Control Module Circuit High Typical of this code Moderate
- P0E73 Control Pilot Signal High Frequency Typical of this code Moderate
- P2107 Throttle Actuator A Control Module Processor Typical of this code Stop driving High
- P2450 Evaporative Emission System Switching Valve Performance/Stuck Open Typical of this code Moderate
- P24B0 Particulate Matter Sensor Circuit Low Typical of this code Moderate
- P2611 Air Conditioning Refrigerant Distribution Valve A Control Circuit/Open Typical of this code Low
- P2A40 Alternative Fuel System - Injector Leakage to Rail Detected Typical of this code High
- U0009 High Speed CAN Communication Bus (-) Shorted to Bus (+) Typical of this code Stop driving High
- U0011 Medium Speed CAN Communication Bus Performance Typical of this code Moderate
- U0013 Medium Speed CAN Communication Bus (+) Low Typical of this code Moderate
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.
Others with this symptom
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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