C1511 on Mercedes-Benz: How to Diagnose & Fix
Torque Sensor 1 Malfunction (Torque Sensor Abnormal)
1 Mercedes-Benz model · 1 documented issue · 1 critical · $400-$5,000 repair
C1511 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)
C1511 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 C1511 mean on a Mercedes-Benz?
C1511 stands for "Torque Sensor 1 Malfunction (Torque Sensor Abnormal)." A Toyota/Lexus/Scion-specific chassis code in the electric power steering (EPS) system. The torque sensor in the steering column converts the rotational torque input from the steering wheel into an electrical signal that tells the power steering ECU how much steering effort the driver is applying, and therefore how much assist to provide. C1511 sets when the ECU sees an abnormal or out-of-range signal from torque sensor 1. The usual result is that the ECU disables power assist as a fail-safe, so the steering becomes very heavy — especially at parking speeds — with the EPS/power steering warning light on. The car remains steerable but takes noticeably more effort. On Mercedes-Benz it is documented across 1 model: GLE.
What are the most common causes of C1511?
The most common causes of C1511 are: Faulty torque sensor, which is built into the steering column assembly on most applications, Open, shorted, or chafed torque sensor wiring harness, Poor or corroded connection at the sensor or ECU connector, Torque sensor zero point/calibration not performed after column, ECU, or alignment work, Low system voltage or a weak battery/charging system, Failed power steering ECU. The specific cause varies by vehicle.
How much does it cost to fix C1511 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 C1511 on a different make?
View C1511 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.