Symptom
Heavy or stiff steering
The steering requires noticeably more effort than usual, often worst at parking speeds where assistance matters most. On hydraulic systems the usual causes are low fluid, a worn pump or a slipping drive belt; on electric systems it is more often the assistance being deliberately reduced because a module has detected a fault elsewhere.
Also described as: stiff steering, heavy steering, hard to steer, steering feels heavy, no power steering, steering stiff at low speed, فرمان سنگین شده, فرمان سفت است, direccion muy dura, volante duro, cuesta girar volante, الدركسيون ثقيل, المقود صعب اللف, الستيرنج قاسي
Some causes mean you should stop driving
2 of the 18 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 steering requires noticeably more effort than usual, often worst at parking speeds where assistance matters most — and that is the pattern, because assistance is greatest at low speed by design.
On hydraulic systems the usual causes are low fluid, a worn pump or a slipping drive belt, and all three are checkable in minutes. Look at the fluid rather than only its level: froth means the pump is drawing air, which both explains the heaviness and will destroy the pump if left.
On electric systems it is more often the assistance being deliberately reduced because a module has detected a fault elsewhere. That is an important distinction, because nothing in the steering has broken — the module has withdrawn help it no longer trusts itself to provide, and the repair may be a sensor or a calibration.
Supply comes first on an electric system. The motor draws a large current at full lock and low speed, so a tired battery, a poor earth or a failing alternator produces heavy steering — and it usually arrives with other unrelated warnings, which is the clue.
Then the mechanical population, which is the same for both types. Seized track rod ends or ball joints, a seized upper strut mounting, and under-inflated front tyres, which is the free check nobody makes: pressures well below the placard figure make parking noticeably harder and cost fuel at the same time.
Steering that becomes heavy suddenly, or that comes and goes, is more urgent than steering that has always been heavy — because the change is what catches a driver out mid-manoeuvre.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Hydraulic system, fluid low or frothy | Low fluid, or air being drawn in on the suction side — froth is the finding, not the level | Look at the fluid's appearance as well as its height. Inspect the low-pressure hose between reservoir and pump. | Repair the suction leak, refill with the specified fluid and bleed lock to lock. Do not run it frothy. |
| Heavy with a whine that rises with steering angle | The hydraulic pump — worn, or starved by air or a restriction | The whine is the corroborating symptom and has its own entry. Measure system pressure where a gauge is available. | Renew the pump and flush the system. Debris from a failing pump reaches the rack. |
| Belt glazed, slipping, or squealing at full lock | The drive belt not turning the pump under load | Inspect the belt and tensioner. Squeal at full lock is the classic slipping signature. | Renew the belt and tensioner. Check the pump turns freely before blaming the belt alone. |
| Electric system, heavy with a steering or other warning lamp | Assistance withdrawn deliberately — the module no longer trusts an input | Read steering module codes. Test battery and charging first, since low supply produces exactly this. | Repair the supply or the named input. A calibration is a common answer and needs no part. |
| Front tyre pressures well below the placard figure | Ordinary — under-inflation makes parking noticeably harder | Gauge all four cold against the door sticker. This is the free check nobody makes. | Inflate to specification. It also costs fuel continuously, so it is worth checking regardless. |
| Heavy in one direction only, or notchy through the travel | A seized track rod end, ball joint, or upper strut mounting rather than the assistance | Turn lock to lock with the wheels off the ground and feel for tight spots. Assistance faults are usually symmetrical. | Renew the seized component and align the steering afterwards. |
-
Hydraulic system, fluid low or frothy
- Likely cause
- Low fluid, or air being drawn in on the suction side — froth is the finding, not the level
- How to confirm it
- Look at the fluid's appearance as well as its height. Inspect the low-pressure hose between reservoir and pump.
- What fixes it
- Repair the suction leak, refill with the specified fluid and bleed lock to lock. Do not run it frothy.
-
Heavy with a whine that rises with steering angle
- Likely cause
- The hydraulic pump — worn, or starved by air or a restriction
- How to confirm it
- The whine is the corroborating symptom and has its own entry. Measure system pressure where a gauge is available.
- What fixes it
- Renew the pump and flush the system. Debris from a failing pump reaches the rack.
-
Belt glazed, slipping, or squealing at full lock
- Likely cause
- The drive belt not turning the pump under load
- How to confirm it
- Inspect the belt and tensioner. Squeal at full lock is the classic slipping signature.
- What fixes it
- Renew the belt and tensioner. Check the pump turns freely before blaming the belt alone.
-
Electric system, heavy with a steering or other warning lamp
- Likely cause
- Assistance withdrawn deliberately — the module no longer trusts an input
- How to confirm it
- Read steering module codes. Test battery and charging first, since low supply produces exactly this.
- What fixes it
- Repair the supply or the named input. A calibration is a common answer and needs no part.
-
Front tyre pressures well below the placard figure
- Likely cause
- Ordinary — under-inflation makes parking noticeably harder
- How to confirm it
- Gauge all four cold against the door sticker. This is the free check nobody makes.
- What fixes it
- Inflate to specification. It also costs fuel continuously, so it is worth checking regardless.
-
Heavy in one direction only, or notchy through the travel
- Likely cause
- A seized track rod end, ball joint, or upper strut mounting rather than the assistance
- How to confirm it
- Turn lock to lock with the wheels off the ground and feel for tight spots. Assistance faults are usually symmetrical.
- What fixes it
- Renew the seized component and align the steering afterwards.
Codes that produce this symptom (18)
Listed with the codes that most typically present this way first — the likeliest place to start.
- P0635 Power Steering Control Circuit Typical of this code Moderate
- P0636 Power Steering Control Circuit Low Typical of this code Moderate
- P0637 Power Steering Control Circuit High Typical of this code Moderate
- U0130 Lost Communication With Steering Effort Control Module Typical of this code High
- U0131 Lost Communication With Power Steering Control Module A Typical of this code High
- U0319 Software Incompatibility With Steering Effort Control Module Typical of this code Moderate
- U0320 Software Incompatibility With Power Steering Control Module Typical of this code Moderate
- U0419 Invalid Data Received From Steering Effort Control Module Typical of this code High
- U0420 Invalid Data Received From Power Steering Control Module A Typical of this code High
- C0529 Steering Angle Sensor Module Missing Calibration Moderate
- P0551 Power Steering Pressure Sensor/Switch Circuit Range/Performance Low
- U0107 Lost Communication With Throttle Actuator A Control Module Stop driving High
- U0126 Lost Communication With Steering Angle Sensor Module Moderate
- U0134 Lost Communication With Power Steering Control Module — Rear High
- U0328 Software Incompatibility With Steering Angle Sensor Module High
- U0428 Invalid Data Received From Steering Angle Sensor Module High
- U0435 Invalid Data Received From Power Steering Control Module — Rear High
- U0537 Invalid Data Received From Column Lock Module Stop driving 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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