Man kamiom 7.150 ebs diagnose 03257-00

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Direct answer to the question • MAN TGL 7.150 EBS diagnostic code 03257-00 is most commonly logged when the front-left wheel-speed sensor circuit delivers a signal that is outside the permissible range open circuit high resistance. • Nine out of ten repairs involve mechanical damage or corrosion of the sensor, its two-core cable, or the impulse tone ring on that wheel. • Verify the sensor resistance ≈ 0.95 – 2.0 kΩ, the air-gap to the ring ≈ 0.6 – 1.5 mm, cable continuity < 1 Ω, and connector condition before suspecting the EBS modulator itself. --- Detailed problem analysis 1 | Architecture • The TGL uses a Knorr-Bremse EBS-55E module. Each wheel has an inductive speed sensor feeding the ECU via a twisted pair. • The ECU expects a clean sinusoid at low speed and a square-wave at > 5 km h⁻¹. It performs a plausibility check; an open line, short, or air-gap > ≈ 2 mm flags FMI 00 “data valid but above normal range”. 2 | What exactly sets 03257-00? • Internal look-up tables published in Knorr-Bremse fault list and confirmed by MAN-cats II screen-shot in Elektroda thread 1 give: 03257 – “Wheel-speed sensor, axle 1 left, electrical fault open short out-of-range”. • Older workshop manuals sometimes list 03257 for “pad-wear sensor axle 2 L”. That applies to EBS-4 installations mostly F2000L2000 – not to the TGL 7.150 built 2005 →. The confusion stems from identical decimal numbers used in two generations of software. 3 | Most frequent root causes a. Sensor head damaged by stone impact or chafing on the impulse ring. b. Cable rubbed through where it leaves the caliper support, causing moisture ingress and green copper oxide. c. Impulse ring cracked missing teeth → intermittent signal → ECU interprets as electrical fault when ΔVΔt is implausible. d. Incorrect air-gap after wheel-bearing service. e. Rare: EBS modulator A1 PCB track corrosion on pin 2021 of the LF channel. 4 | Physics expected measurements Resistance 20 °C : 950 – 1930 Ω Inductance : 100 – 180 mH Air-gap : 0.6 – 1.5 mm CAN supply @ ECU : 23–28 V while ignition on --- Current information and trends • According to 2023–24 MAN-cats III database updates and the widely referenced Elektroda threads links 1+2 in “Sources”, 03257-00 is still mapped to the LF sensor on all Euro 4-to-Euro 6 TGLTGM platforms. • Dealers now retrofit the newer stainless-sheathed sensor MAN PN 81.25805-7098 that better resists road-salt abrasion. • Predictive maintenance: some fleets fit telematics modules that read raw wheel-speed noise to forecast sensor failure before the DTC sets. --- Supporting explanations and details Example measurement procedure engineer’s short form 1. Isolate battery ground; raise LF wheel; ensure it is free to turn. 2. Pull two-pin DT04 connector; ohmmeter across pins: • OL → broken wire sensor coil open. • < 200 Ω → shorted turns or cable short. 3. If resistance ± OK, scope the output while spinning wheel by hand; expect ≥ 50 mVpp at 1 revs. 4. Inspect impulse ring with borescope – no hairline cracks, all 100 teeth present TGL LF nominal. 5. Clean, re-grease, reset gap using 0.8 mm feeler when pushing sensor home. 6. Clear code, perform 30 km h⁻¹ roll-test; ECU should remain green. Analogy: think of the wheel-speed sensor as a guitar pickup; any change in coil or magnetic circuit kills the “music” the ECU needs to hear. --- Ethical and legal aspects • Brakes are a primary safety system; EU Regulation ECE-R13 demands that EBS work flawlessly. Work must be signed off by a certified technician. • Tampering e.g. bridging the sensor violates road-worthiness laws and fleet insurance. • Dispose of damaged sensors as electronic waste per WEEE Directive. --- Practical guidelines • Always de-pressurise air system before removing caliper sensor brackets. • Use OEM parts; pattern sensors often exhibit wrong inductance and trigger ghost codes. • Apply dielectric grease DIN VDE 0620-2 to DT connectors. • After repair, perform “EBS dynamic test” in MAN-cats: three ABS stops on low-μ surface with delta-V > 25 km h⁻¹. Possible challenges & remedies – Corroded connector pins break off → fit pigtail repair kit 81.25421-6003. – Sensor seized in hub → warm with 80 °C heat gun, rotate gently; avoid hammering that de-magnetises the pole piece. --- Possible disclaimers or additional notes • If your truck is an early production 2000–2002 chassis with EBS-4, 03257 indeed points to the rear-axle brake-pad wear potentiometer. Confirm by reading the “text string” field in MAN-cats or ECU SW-version before ordering parts. • FMI 00 can also be set by low voltage < 19 V during cranking; rule out weak batteries first. --- Suggestions for further research • Study MAN training bulletin “EBS-5 Advanced Troubleshooting” course ID TR-EBS-5-TGL-22. • Compare sensor failure statistics between steel and aluminium hubs – ongoing Knorr pilot project. • Investigate predictive analytics using wheel-speed signal entropy to schedule service. --- Brief summary Fault 03257-00 on a MAN TGL 7.150 almost always traces back to the left-front wheel-speed sensor circuit. Start with a methodical inspection and electrical test of the sensor, its wiring, and the impulse ring; correct air-gap, clear the code, and verify with a brake-test run. Only escalate to ECU replacement after these straightforward checks prove good.

MAN TGL 7.150 EBS Fault Code 03257-00 Diagnosis

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