BMW 6137: AL Engine Position Sensor Fault Diagnosis and Repair

6137 means AL: Engine position sensor, a fault in the position feedback for the Active Steering electric motor rather than the engine crankshaft sensor. The AFS or ASA control unit stores it when steering-drive position information is missing, implausible, or inconsistent with the commanded steering movement. What Does BMW 6137 Mean? BMW 6137 means the Active Steering controller cannot trust the position signal from the electric motor integrated with the steering gear. BMW's label says engine position sensor because the German source term refers to the steering system's motor, which can otherwise be mistaken for a combustion-engine sensor. In practice, the controller needs this feedback to regulate the variable steering ratio and to initialize the rack's center relationship. The exact hardware and test plan vary by chassis and AFS generation, so the VIN-specific BMW procedure must identify whether the sensor, wiring, motor assembly, or steering gear is serviceable separately. Code: 6137 Definition: AL: Engine position sensor Module: AFS / ASA Active Steering Key data: steering-motor position compared with steering angle and commanded movement Typical cause: interrupted or implausible motor-position feedback Severity: high when steering assistance or ratio changes Note: this is not the DME crankshaft-position sensor First identify the reporting module. AFS or ASA ownership separates this fault from a DME crankshaft or camshaft sensor code. What Symptoms Does BMW 6137 Cause? BMW 6137 commonly appears with an Active Steering warning and a steering ratio that becomes fixed or feels unfamiliar. The most useful symptom is a mismatch: the steering wheel moves smoothly while the AFS motor-position value freezes, jumps, or fails to follow. Assistance may remain, so steering feel alone cannot clear the sensor. • An Active Steering warning appears during startup, while the steering wheel remains mechanically connected and controllable. • The variable steering ratio stops changing, making low-speed steering feel heavier or less direct than usual. • AFS initialization aborts because motor position does not follow the steering-angle movement through the requested sweep. • Live motor-position data freezes at one value although the steering wheel angle changes smoothly in both directions. • The displayed position jumps when the steering-rack harness flexes, suggesting an intermittent conductor or connector pin. • DSC warnings may accompany 6137 because stability control cannot rely on the requested Active Steering correction. Why Does BMW 6137 Occur? The fault begins when the AFS controller loses a credible relationship between electric-motor position and steering movement. Low system voltage and disturbed initialization are inexpensive possibilities, followed by connector damage, harness fatigue, sensor failure, or internal steering-gear damage. A stored 6137 does not by itself prove that the complete rack needs replacement. • Battery voltage falls during startup, interrupting AFS initialization before the motor-position reference becomes stable. • A previous alignment or steering repair leaves the Active Steering center adaptation incomplete or internally inconsistent. • Moisture or weak connector-pin tension intermittently interrupts the low-level feedback signal near the steering gear. • Repeated rack movement fatigues the short harness section leading to the motor-position sensor inside its insulation. • The motor-position sensor develops dead spots, producing jumps while the mechanical steering movement remains continuous. • Internal wear or damage in the Active Steering drive prevents sensor movement from matching the commanded motor motion. How Can OBDThink Diagnose BMW 6137? OBDThink is an independent BMW coding and diagnostics app and is not affiliated with BMW AG. Use it to save the AFS or ASA scan, occurrence details, and supported live values before clearing anything. Availability of motor-position and steering-angle channels depends on the chassis, control-unit software, adapter, and vehicle configuration. • 1. Save the complete AFS or ASA scan, stored freeze frame data, fault frequency, and current status. • 2. Check battery voltage during startup and note whether 6137 returns only after a low-voltage event. • 3. Plot steering angle and motor position while turning slowly through equal movements left and right. • 4. Stop if steering binds, jerks, or suddenly becomes heavy; mechanical safety takes priority over continued testing. • 5. Inspect the steering-gear connector for moisture, spread connector pins, oil contamination, or a loose locking tab. • 6. Flex the nearby harness gently while watching motor-position data for a reproducible jump or dropout. • 7. Run the VIN-specific BMW Active Steering test plan to verify initialization and sensor plausibility requirements. • 8. After repair, initialize AFS correctly, clear stored fault codes, and repeat the same controlled steering sweep. IF motor position freezes AND steering angle changes smoothly, THEN test the sensor circuit and short rack harness first. ELSE IF both values move smoothly BUT initialization fails, THEN verify center adaptation, alignment, and related AFS faults. ELSE IF movement binds or position changes in steps, THEN stop the test and inspect the Active Steering drive mechanically. A repeatable motor-position dropout during harness movement points toward wiring; a smooth signal with failed initialization points elsewhere. How Is BMW 6137 Repaired? Repair follows the evidence rather than the price of the steering rack. Stabilize battery supply, restore any disturbed connection, and complete the correct initialization before considering internal parts. If the position trace still contains dead spots with verified wiring, the VIN-specific parts catalog and BMW procedure determine whether the sensor or full steering gear is replaced. • Low cost: charge, test, and register the battery when startup voltage instability caused the interrupted initialization. • Low cost: clean the steering-gear connector and restore proper connector-pin tension without bending its contacts. • Moderate cost: repair the identified broken harness section with sealed joints and adequate movement relief. • Moderate cost: correct wheel alignment, then perform the prescribed Active Steering center initialization and verification. • High cost: replace the proven motor-position sensor when BMW lists it separately for the installed steering gear. • High cost: replace and program the Active Steering gear only after electrical and adaptation tests exclude alternatives. After repair, confirm that motor position follows steering angle continuously and that 6137 no longer occurs after initialization and a test drive. Can You Drive with BMW 6137? Driving is not advisable when steering becomes heavy, jerky, off-center, or unpredictable, or when a red steering warning appears. Active Steering changes the relationship between steering-wheel input and road-wheel angle; uncertain feedback can disable the variable ratio and affect DSC coordination even when a mechanical connection remains. If the warning is yellow, steering remains smooth, and assistance is unchanged, move the car only as far as necessary for diagnosis at reduced speed. Avoid motorways and abrupt maneuvers. Stop immediately if effort rises, the wheel fails to self-center, or the steering response changes during the trip. Stop driving if steering binds, becomes suddenly heavy, or responds unpredictably; arrange recovery instead of continuing the test. Which Questions Are Frequently Asked About BMW 6137? The important questions distinguish the AFS motor sensor from engine sensors and separate a wiring fault from a damaged steering gear. The answers below keep the diagnosis centered on module ownership, synchronized live data, initialization, and safe steering behavior rather than automatic parts replacement. • Is 6137 a crankshaft-position sensor code? No. When AFS or ASA stores 6137, the label refers to the Active Steering electric-motor position sensor, not the DME engine-speed sensor. • Can a weak battery trigger 6137? Low startup voltage can interrupt AFS initialization, but a repeatable motor-position dropout still requires connector, harness, and sensor testing. • Does 6137 always require a steering rack? No. Verified voltage, wiring, synchronized position traces, and correct initialization should precede any decision to replace the steering gear. Preserve the original AFS evidence, compare both position signals through the same steering sweep, and repair only the branch that fails. That sequence protects you from confusing BMW's wording with an engine-sensor problem or replacing an expensive rack before proving its internal sensor is defective.