Mercedes MAS control unit A0115457932 M103 USA W124 300E 300TE W126 W201 190E 2.6
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Used genuine Mercedes-Benz MAS control unit A 011 545 79 32 in US specification for the six-cylinder M103 in W124, W126 and W201.
Genuine part – not aftermarket · US specification for six-cylinder M103 · Connector header undamaged
Condition of this part
Used genuine part. Print on housing: 011 545 79 32 MAS [07], M103 USA, (K) 05 3700 45, additional MAS sticker. Stainless steel retaining bracket with slight signs of use, rotary lock on top (0 / I) present, connector header undamaged.
Function and location
The MAS combines several individual relays in one unit: fuel pump relay, A/C relay with compressor cut-off and overvoltage protection, and on the US specification additionally the magnetic clutch of the secondary air pump. The engine speed signal to the tachometer also runs through the MAS. The rotary knob on top is the lock in the connector (I = locked, 0 = release). Without the MAS the engine will not start.
Installation location: In the engine bay behind the battery on the firewall, in the control unit box under the plastic cover next to the KE control unit.
How can you tell that the MAS control unit is faulty?
- Engine cuts out after approx. 15 minutes when warm and only restarts after cooling down
- No start, the fuel pumps do not run
- Tachometer drops to 0, the other gauges keep working
- A/C compressor does not engage or switches off after a few minutes
Compatible vehicles
US specification, six-cylinder M103 with MAS only. Please compare the number on your own MAS.
| Model series | Models |
|---|---|
| E-Class W124 sedan (six-cylinder M103, approx. 1990–1993) | 260 E (124.026, sold in the US as 300 E 2.6), 300 E (124.030), 300 E 4MATIC (124.230) |
| E-Class S124 wagon (six-cylinder M103, approx. 1990–1993) | 300 TE (124.090), 300 TE 4MATIC (124.290) |
| S-Class W126 (six-cylinder M103, 1990–1991) | 300 SE (126.024), 300 SEL (126.025) |
| 190 W201 (six-cylinder M103, 1990–1993) | 190 E 2.6 (201.029) |
Part numbers: Mercedes-Benz: A 011 545 79 32 / A0115457932 · Kostal: 05 3700 45 / 05370045 · Interchangeable per aftermarket catalog: A 007 545 65 32 / A0075456532, A 012 545 46 32 / A0125454632
Scope of delivery: see product photos. Control unit with stainless steel retaining plate.
⚠ Important: compare the part number before buying
US-spec – Print M103 USA. Interchangeable with A 007 545 65 32 (Kostal 05 3700 15) and A 012 545 46 32 per aftermarket catalog.
Not four-valve M104 – 300 E-24, 300 CE-24, 300 TE-24 and 300 SL-24 have different MAS units (A 011 545 83 32, A 008 545 85 32, A 011 545 82 32).
Not V8 and not E 320 – 500 SL M119 has A 011 545 85 32, the E 320 has its own control unit A 015 545 43 32.
Older vehicles – Six-cylinder cars before approx. 1990 still have individual relays for fuel pump, overvoltage protection and A/C instead of a MAS.
Does not fit:
- Four-valve M104 (24V)
- 500 SL M119 and V8
- E 320
- four-cylinder
- Diesel
Does this part fit your car? Send us the VIN (chassis number) and model year – we'll check it for free: +49 179 8991069 (Mon–Fri 8 am–6 pm) or via our contact form.
FAQ
Does the MAS control unit definitely fit my car?
Please compare the number on your own MAS with the part numbers on this page. If you are unsure, send us your VIN by phone or via the contact form before buying. We will check it against the parts catalog free of charge and tell you definitively whether this part fits.
Do I get exactly the part shown in the photos?
Yes. The photos show the actual part you will receive.
Related categories: W201 · W124 · W126
KFZTeile-Thot specialises in spare parts for Mercedes classic cars. Free shipping within Germany, 60-day return policy.
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