VW Polo Power Steering Fault
Three weeks in the workshop. A replacement part already fitted. But the red steering warning light was still lit, and the power steering wasn’t working.
“It’s no different. The light’s still on, and the steering’s heavy.”
That’s what Mr H told the team at CSN Autos when he called about his Volkswagen Polo. The vehicle had already been through a steering repair at another garage, but the problem hadn’t been resolved.
By this point, he wasn’t sure whether the fault could be fixed at all.
To move forward with the diagnosis, we arranged for the vehicle to come into our Wymondham workshop for a full technical evaluation. That allowed our team to carry out a structured diagnostic process from the beginning, using the correct tools, procedures and information at each stage. It’s the same process we follow whenever a fault proves difficult to pin down.
The next step was to take a closer look at the fault and begin working through the system one stage at a time.
VW Polo Power Steering Fault Verified During Our First Assessment
When Mr H’s VW Polo arrived at CSN Autos in Wymondham, he had already reported two persistent issues: no steering assistance and a warning light displayed on the dashboard. Our own checks confirmed the same result. The steering felt heavy throughout, and the red warning light stayed active on the display.
A replacement steering pump/motor unit had been installed by another garage. Despite that, the fault hadn’t changed. Steering effort was still high, and the dashboard warning hadn’t cleared. With that in mind, we moved ahead with our initial assessment.
We started by reviewing the previous work and carrying out a visual inspection of the steering components. The new pump/motor appeared to be in good physical condition, and there were no signs of fluid loss or installation damage.
Next, we connected our Volkswagen dealer-level diagnostic tool and ran a full scan of the power steering module. This revealed a single stored fault:
00816 – Power Steering Sensor (G250)
This code highlights a problem with the expected input from the power steering sensor not being received by the control module. However, it didn’t confirm whether the cause was the sensor itself, a compatibility mismatch, incorrect configuration, or something else.
With the fault code verified and the symptoms matching the report, we progressed to the next phase of our structured technical evaluation.
Identifying the Root Cause of VW Polo Power Steering Fault Code 00816
With fault code 00816 stored in the system and the vehicle’s symptoms confirmed, we began our structured technical evaluation. These are the steps our team followed to uncover the cause of the fault:
Step 1: Checking Electrical Supply to the Pump/Motor
Our first task was to ensure the pump/motor unit was receiving the correct electrical feed.
- We used Volkswagen’s wiring diagram to locate the main power and earth circuits at the connector
- With the ignition on, we tested both supply and ground using a multimeter
What we found:
Battery voltage was present, and the ground connection was intact. The circuit showed no signs of voltage drop or damage. There were no supply-related issues. The pump/motor was receiving the correct electrical input to operate, which ruled out a basic power fault.
Step 2: Inspecting Module Communication and Sensor Signals
We then turned our attention to data communication.
- We used our Volkswagen ODIS diagnostic platform to access the steering control module
- We checked the fault memory and reviewed the serial data available from the steering control module
- We confirmed the module was live and communicating with the wider vehicle network
What we found:
The control module was responsive and active. However, the expected signal from the power steering sensor (G250) was missing or invalid. As a safety measure, the system had disabled steering assistance. With communication confirmed, this narrowed the fault to a potential signal mismatch, compatibility issue, or incomplete setup.
Step 3: Checking Compatibility of the Fitted Pump/Motor
Because the pump/motor unit had already been replaced by another garage, we needed to confirm whether it matched this VW Polo’s build.
- We cross-referenced the part number with Volkswagen’s EPC using the car’s VIN
- We also reviewed compatibility across Polo variants from this model year
- Some VW Polo models of this generation were built with steering systems from different suppliers, and not all pumps are interchangeable
- A mismatched part, even if it looks correct, can output a signal the system can’t recognise, triggering fault code 00816
What we found:
The fitted pump/motor was not the correct version for this vehicle. The steering control module was receiving an unexpected signal format, which led the system to disable power assistance.
Step 4: Confirming Coding and Setup Status
We then checked whether the replacement module had been programmed correctly.
- We accessed the pump’s internal control unit via ODIS
- We reviewed the module information to check whether it had been paired to the vehicle after installation
- We examined the coding and adaptation data
What we found:
The new pump/motor had not been coded. Without this, the steering system couldn’t interpret the signal from the power steering sensor correctly. As a safety measure, the system disabled steering assistance.
This confirmed the root cause: the part fitted was not only incompatible but had also not been programmed to the vehicle.
Repair Steps: Fixing the VW Polo Power Steering Fault
With the fault confirmed and the cause identified, we contacted Mr H to explain our findings. Once the work was approved, we began the repair process.
- We used the vehicle’s VIN to identify and order the correct pump/motor unit from Volkswagen’s parts system
- Before fitting the new unit, we carefully inspected the surrounding harness, terminals, and hydraulic fittings for any signs of wear, damage, or corrosion
- We removed the incompatible part and installed the new, vehicle-specific unit in its place
- Once in position, all electrical connectors were reattached and the hydraulic system was bled to eliminate trapped air
With the correct part installed, we carried out the required configuration.
- Using the Volkswagen ODIS platform, we connected to the control module
- The new pump/motor was coded to the vehicle and integrated into the steering system
- We cleared the fault code and ran a full post-repair test
The warning light was no longer lighting up the dashboard. Power steering functionality returned, and the vehicle performed well on the road test.
Restored Steering and Cleared Fault Code on VW Polo
With the system confirmed as fully operational, the final checks marked the completion of the job. The repair had addressed the source of the fault, not just the symptoms, and the difference was immediate.
This case showed the value of structured testing carried out by technicians with access to manufacturer data and the tools to interpret it. Fault code 00816 had appeared difficult to trace, but methodical evaluation revealed the exact cause and the right solution.
Although the vehicle had already spent time off the road, the issue was diagnosed and fixed in one visit at our Wymondham workshop.
Mr H collected the car, knowing it was operating as it should again, and was protected by our 12-month parts and labour guarantee.
No Power Steering? Get Your VW Polo Professionally Tested
A steering warning light or sudden loss of power assistance is more than an inconvenience. It’s a sign your vehicle needs a structured technical assessment.
At CSN Autos in Wymondham, we carry out diagnostic evaluations using Volkswagen-approved systems and test procedures. Whether you’re experiencing heavy power steering, seeing a warning light or just know something isn’t right, we’ll find out why.
Why Norwich drivers trust us for VW power steering repair:
- Award-winning team: South Norfolk Small Business of the Year 2024
- Full diagnostic process using VW diagnostic equipment
- We pinpoint causes to avoid unnecessary parts or delays
- Courtesy cars available while your vehicle is in for repair
- All repairs backed by a 12-month parts and labour guarantee
Join the {{review-count}} local drivers who rate CSN Autos {{average-rating}} stars on Google for trusted, specialist repairs.
Call 01953 425983 to book your technical evaluation.
