Glow Plug Control Relay 6461532579 – Diesel Relay Replacement

The glow plug control relay (OEM 6461532579) is a key engine electrical component designed to manage the operation of the glow plug system on Mercedes-Benz diesel engines. It functions as the control module that regulates electrical current to the glow plugs at start-up, ensuring precise timing and power delivery during the pre-heating phase. Without a properly working relay, pre-heating may be insufficient or inconsistent, leading to difficult engine starts, excessive exhaust smoke, and reduced combustion efficiency. This replacement unit is engineered to match original equipment specifications for fit and reliability on compatible Mercedes vehicles.

OEM Number: 6461532579, 2502195, A646153257980, 646153257980
 
Operating Voltage : 12V

Number of Cylinders : 4

Quantity : 1

Our SKU: TM6461532579_94

All our Glow Plug Control Relay 6461532579 are OEM quality and reliable after market car parts. This Glow Plug Control Relay 6461532579 is specifically compatible with Mercedes-Benz: C-Class, CLC-Class, CLK, E-Class, Sprinter 3-T, Sprinter 3.5-T, Sprinter 4.6-T, Sprinter 5-T, Sprinter Classic 3.5-T, Sprinter Classic 4.6-T, Viano, Vito, Vito / Mixto, .

Please use our make-model-year tool to check this part's compatibility with your vehicle. However, please note that our tool is for reference only and we recommend that you check the part number on your old unit prior to purchasing.

If you are still not sure about the compatibility of this part to your vehicle, please supply us with the VIN number or Reg number in our live chat or contact form! You can also find details on our purchasing & shipping guide here.

Key Benefits

Precise Glow Plug Control
The relay accurately governs the current supplied to each glow plug, ensuring the required power and timing for efficient cylinder pre-heating during cold starts. This controlled pre-heating promotes smoother ignitions and consistent diesel combustion.

Restores Reliable Cold Starts
A malfunctioning relay can cause extended crank times, hard starts, or failure to start, especially in colder weather conditions. Replacing the relay restores reliable engine starts when temperatures drop. 

OEM-Compatible Fit
This replacement relay is designed to match OEM reference number 6461532579 (also listed as A6461532579) and installs directly in place of the original without requiring modification.

Improves Engine Performance and Emissions
Accurate glow plug operation helps ensure complete combustion at start-up, which can reduce white smoke emissions, minimise check engine or glow plug warning lights, and improve overall fuel efficiency during warming phases.

Durable Construction
Manufactured from quality electrical components, this control relay is built to withstand typical under-hood conditions and provide dependable long-term performance when fitted correctly.

Frequently Asked Questions (FAQs)

Q: What does the glow plug control relay do?
A: The glow plug control relay regulates the electrical current delivered to the glow plugs based on input from the engine control unit, enabling correct pre-heating of the combustion chambers so the diesel engine starts smoothly and efficiently.

Q: What are common symptoms of a faulty glow plug control relay?
A: Symptoms of relay issues include hard starting, especially in cold weather, extended crank times, rough engine idle after start-up, excessive white smoke from the exhaust, and illumination of glow plug or engine warning lights.

Q: Which vehicles use part number 6461532579?
A: Part number 6461532579 is commonly used on a range of Mercedes-Benz diesel models including C-Class (W204), E-Class (W211, S211), and other related CDi applications. Always verify compatibility with your VIN or existing part number before ordering.

Q: Is this relay a direct replacement part?
A: Yes. This glow plug control relay is designed as a direct replacement for the original unit with OEM reference 6461532579/A6461532579 and installs without requiring additional modifications.

Q: Should I check glow plugs when replacing the relay?
A: Yes. Although the relay controls current to the glow plugs, it’s good practice to inspect the glow plugs and related wiring when experiencing start-up issues, as faults in multiple components can produce similar symptoms.