5E43

What the Code Means

Code 5E43 points to an internal fault in the steering angle sensor. The sensor is built into the SZL module (steering column switch cluster), so it isn't serviced as a separate part — the repair covers the whole module.

The internal fault usually comes from contamination or wear in the optical sensor or potentiometer. The signal goes bad, and the DSC module loses reliable steering angle data it needs for stability calculations. DSC, ABS, and traction control then drop into fault mode and switch on the warning lights.

Symptoms

• DSC warning light on;
• ABS light on;
• traction control disabled;
• warning lights come on when you turn the steering wheel;
• hill start assist inactive.

Diagnosis and Repair

Step 1. Read the Codes

Pull the fault codes with ISTA or INPA and confirm you have 5E43 with no accompanying SZL communication errors.

Step 2. Clean the Sensor

Remove the SZL module and clean the steering angle sensor with contact cleaner. If the optical sensor or potentiometer is contaminated, this often clears the fault.

Step 3. Replace the SZL Module

If cleaning doesn't help, the SZL module needs replacement — the OEM part number depends on the specific model.

Step 4. Coding and Calibration

After fitting the new SZL, code it and calibrate the steering angle sensor with ISTA. Without calibration, DSC and ABS won't work correctly.

Secondary Problems

• loss of DSC and ABS functions if the fault is ignored — reduced vehicle stability and higher risk of an accident;
• complete SZL module failure, which takes out the turn signals, wipers, and cruise control.

Don't put off the repair: the fault progresses from intermittent warnings to permanent failure of the safety systems and total SZL failure.