FAQ
TL;DR: Typical controller sits near the passenger footwell; some replacement "drivers" cost around PLN 50, and "The rotor is a total failure." [Elektroda, radiogaga, post #16796523]
Why it matters: This FAQ helps Smart ForFour 2005 owners quickly locate and diagnose EPS faults without guesswork.
Quick Facts
- Likely location: EPS controller/motor assembly on the right, ahead of passenger legs. [Elektroda, coperfild, post #16785496]
- Symptom trend: assist may intermittently need a hard wheel jerk to engage. [Elektroda, spinacz, post #16792315]
- Common root cause: motor winding/rotor defect rather than the ECU. [Elektroda, radiogaga, post #16794817]
- Donor option: Mitsubishi Colt EPS is compatible; RHD low‑mileage units preferred. [Elektroda, radiogaga, post #16792167]
- Service market: regen offers cited around PLN 1400 with "lifetime" warranty claims. [Elektroda, spinacz, post #16794829]
Where is the Smart ForFour 2005 electric power steering controller located?
Owners report finding the EPS controller/motor assembly on the right side, in front of the passenger’s legs. Remove the lower trim to access it. Some users also peek at the glovebox fuse area for related circuits, but the working location callout is the passenger footwell. [Elektroda, coperfild, post #16785496]
Does fault code C1541 mean I must replace the EPS controller?
One owner saw C1541 with a service manual suggestion to replace the controller. Their shop swapped the controller, but the issue returned after months. Treat C1541 as a starting point. Confirm motor health and torque sensor data before buying parts. [Elektroda, spinacz, post #16785588]
Is the common failure the controller or the motor on ForFour/Colt EPS?
Community diagnosis points to the motor as the usual culprit. Repeated cases cite a manufacturing defect that begins with intermittent assist and progresses to loss of assist. An expert summarized the root cause as a winding fault. [Elektroda, radiogaga, post #16792167]
What exactly fails inside the EPS motor?
Reports cite a winding fault and rotor failure. Over time, the defect causes interruption and then complete loss of assistance. As one expert put it: “Winding fault.” Inspect windings and rotor before assuming the ECU is bad. [Elektroda, radiogaga, post #16794817]
How can I quickly confirm the EPS motor is at fault?
One user measured that the controller delivered voltage to the motor, yet no steering assist was felt. That observation implicates the motor assembly. If power delivery is present at the motor but assist is absent, prioritize motor teardown or swap. [Elektroda, spinacz, post #16790874]
Can I swap in a Mitsubishi Colt unit as a donor?
Yes. The Mitsubishi Colt uses the same EPS setup. A low‑mileage donor from a right‑hand‑drive car is recommended. Verify connectors and mounting points before installation, then calibrate if you swap the torque sensor. [Elektroda, radiogaga, post #16792167]
Why did a replacement controller fix my EPS only for 3 months?
A member reported the car drove about 3 months after a controller swap, then failed again. That pattern suggests the controller was not the root cause. Investigate motor windings and rotor condition to avoid repeat failures. [Elektroda, spinacz, post #16796619]
What are signs I’m dealing with an early‑stage motor defect?
Assist may engage only after you sharply jerk the steering wheel. This intermittent behavior can precede complete loss of assist. Do not ignore it; plan a motor inspection or donor swap to prevent sudden failure. [Elektroda, spinacz, post #16792315]
Is removing the EPS motor difficult on this platform?
Yes. An experienced member warns of a major removal challenge. A critical screw is hot‑connected, and the rotor is considered a total failure point. Plan time, heat, and proper tools before attempting. [Elektroda, radiogaga, post #16796523]
Can the torque sensor be replaced or calibrated separately?
Yes. With a donor unit, replacing the torque sensor is not troublesome. Perform a proper calibration afterward, or the assist will not behave correctly. Scan for faults first to confirm the sensor is the issue. [Elektroda, radiogaga, post #16799152]
What happens if the torque sensor itself fails?
If the torque sensor stops working, the EPS disables assistance entirely as a safety behavior. Confirm with a diagnostic scan and live data. Replace the sensor and calibrate to restore proper function. [Elektroda, licho23, post #16796698]
Is there a budget path if my controller seems dead?
One expert noted that used controllers can be found for about PLN 50. Verify part numbers and test before installation. Remember that many no‑assist cases trace back to the motor, not the controller. [Elektroda, radiogaga, post #16796523]
Are commercial rebuilds worthwhile for this EPS?
A listing mentioned engine and controller regeneration for about PLN 1400 with a lifetime warranty claim. Evaluate the provider’s reputation and what components they actually rewind or replace. Request calibration support details. [Elektroda, spinacz, post #16794829]
How do I diagnose a no‑assist condition quickly?
- Run a computer diagnosis and record codes and live torque data.
- If a donor is available, swap the torque sensor to A/B test.
- Calibrate the sensor after replacement and retest assist engagement.
“Calibration is important.” [Elektroda, radiogaga, post #16799152]
What’s an edge case I should watch for before condemning parts?
If the controller outputs motor voltage but you feel no assist, suspect the motor despite a controller‑related code. This scenario appeared in the thread and led back to the motor assembly. [Elektroda, spinacz, post #16790874]
