C1532 on Mercedes-Benz: How to Diagnose & Fix
Power Steering ECU Malfunction
1 Mercedes-Benz model · 1 documented issue · 1 critical · $400-$5,000 repair
C1532 on Mercedes-Benz by model: symptoms, diagnosis and fix
GLE owners (W166 and W167) report sudden loss of electric power steering assist, sometimes immediately after engine start and sometimes intermittently while driving, accompanied by the red dashboard message "Power Steering Malfunction - See Operator's Manual." Steering becomes very heavy, especially at low/parking speeds. Because EPS relies on stable voltage, CAN/FlexRay communication, and accurate sensor data, causes are almost always electrical: EPS control-module/torque-sensor faults, a corroded/loose steering-rack ground or harness connection, a blown power-steering pre-fuse, or a weak 12V battery dropping voltage to the EPS motor. NHTSA recall 16V899000 covers 2016-2017 GLE (350/400/300d/550e/43/63, etc.) where an insufficiently sealed EPS connector lets water into the control unit and deactivates assist, and TSB MC-10231025 addresses a no-assist-after-start software fault of the N68 EPS control unit on later models. This is an electronic EPS-rack fault, separate from mechanical front control-arm bushing wear.
Common Symptoms
- "Power Steering Malfunction, See Operator's Manual" red warning message
- Sudden heavy / hard-to-turn steering, worst at parking speeds
- Intermittent loss and return of power assist after restart
- Steering warning light illuminated
- Occasional correlation with low/weak 12V battery
How to Fix
Diagnose with XENTRY for C15xx EPS codes; first rule out and correct low battery voltage, a blown power-steering pre-fuse, and corroded/loose steering-rack ground and power connectors (common fixable causes). Check VIN for recall 16V899000 (connector reseal + rack inspection/replacement) and applicable EPS software TSBs. If the fault is internal, the EPS control unit / torque sensor or the complete electric steering rack is replaced (or reconditioned) and coded to the vehicle.
Sources for this issue (3)
C1532 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C1532 mean on a Mercedes-Benz?
C1532 stands for "Power Steering ECU Malfunction." Manufacturer-specific chassis code, documented by Toyota/Lexus on electric power steering (EPS) systems as C1532/25 — an ECU internal malfunction relating to a peripheral circuit inside the power steering ECU (paired in service information with C1531/25). The ECU monitors itself and sets the code on an internal fault; on affected models it shuts off the built-in motor relay circuit and stops power assist, making the steering noticeably heavy while the car remains steerable, though some Toyota manuals note assist can continue with this DTC stored. Toyota also uses C1532 with a different sub-code (/32) for a VGRS (variable gear ratio steering) ECU malfunction on some models, and other makes use C1532 for unrelated faults — Subaru documents C1532 as "BLS on stuck," a brake light switch signal stuck on. Confirm against service information for the actual make and model. On Mercedes-Benz it is documented across 1 model: GLE.
What are the most common causes of C1532?
The most common causes of C1532 are: Internal failure of the electric power steering ECU (most common; usually requires ECU/column assembly replacement), Poor power supply or ground to the EPS ECU (corroded, loose, or damaged connector), Low or unstable battery/charging system voltage, Damaged wiring harness between the EPS ECU and the steering assist motor, Water intrusion or corrosion at the steering column / ECU connector, Incomplete or missing ECU initialization / torque sensor zero-point calibration after service. The specific cause varies by vehicle.
How much does it cost to fix C1532 on a Mercedes-Benz?
Published repair estimates on Mercedes-Benz range from $400 to $5,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for C1532 on a different make?
View C1532 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.