Mercedes-Benz 300SEL Electronic Control Relay Replacement at your home or office.

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Electronic Control Relay Replacement Service

How much does a Electronic Control Relay Replacement cost?

On average, the cost for a Mercedes-Benz 300SEL Electronic Control Relay Replacement is $141 with $46 for parts and $95 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
1963 Mercedes-Benz 300SELL6-3.0LService typeElectronic Control Relay ReplacementEstimate$207.35Shop/Dealer Price$247.94 - $330.34
1972 Mercedes-Benz 300SELV8-4.5LService typeElectronic Control Relay ReplacementEstimate$187.35Shop/Dealer Price$227.97 - $310.39
1989 Mercedes-Benz 300SELL6-3.0LService typeElectronic Control Relay ReplacementEstimate$187.35Shop/Dealer Price$227.97 - $310.39
1970 Mercedes-Benz 300SELV8-3.5LService typeElectronic Control Relay ReplacementEstimate$187.35Shop/Dealer Price$227.93 - $310.32
1969 Mercedes-Benz 300SELL6-2.8LService typeElectronic Control Relay ReplacementEstimate$187.35Shop/Dealer Price$228.00 - $310.44
1991 Mercedes-Benz 300SELL6-3.0LService typeElectronic Control Relay ReplacementEstimate$187.35Shop/Dealer Price$227.97 - $310.39
1971 Mercedes-Benz 300SELV8-6.3LService typeElectronic Control Relay ReplacementEstimate$192.35Shop/Dealer Price$232.73 - $314.97
1968 Mercedes-Benz 300SELL6-2.8LService typeElectronic Control Relay ReplacementEstimate$192.35Shop/Dealer Price$233.39 - $316.11
Show example Mercedes-Benz 300SEL Electronic Control Relay Replacement prices

What is the Electronic Control Relay all about?

A wide range of electronic systems must work properly in order for the vehicle to operate. That means there is a need for several different controllers to ensure proper operation. One of the most important is the electronic control relay. You might be more familiar with the term “main relay” because of its role in vehicle performance.

The electronic control relay operates the fuel pump and sends power to the engine’s injectors. Without the main relay, fuel will not flow from the tank to the engine, and your injectors will not atomize gasoline into the combustion chamber. In short, your car wouldn’t run. Electronic control relays are subject to failure from a number of different problems, including outright failure, heat damage, cracked solder and more.

Keep in mind:

  • The electronic control relay may not operate, or may operate intermittently depending on the source of the trouble.
  • A number of other problems can masquerade as a main relay failure, so it’s vital that you have one of our expert mechanics diagnose the issue.

How it's done:

  • The electronic control relay is located and accessed then verified it needs replaced
  • The defective relay is removed from the vehicle
  • The new electronic relay is installed
  • The components that the electronic relay operates are checked for proper operation
  • The vehicle is road tested for proper operation

Our recommendation:

Traditional turnkey ignition the relay will click three times during the starting process. If you listen closely, you should hear a single click when you turn the ignition to “on”. You should hear another when the Check Engine light turns off. Finally, there should be a third click when you turn the key to the “start” position. If you do not hear a click at any of these three points, there may be a problem with the electronic control relay. Have one of our expert mechanics diagnose and replace the relay if required.

What common symptoms indicate you may need to replace the Electronic Control Relay?

  • Engine doesn’t start, especially in cold weather
  • Engine may not start a few minutes after turning it off
  • No sound from the fuel pump when the ignition key is turned to “On”

How important is this service?

Given the fact that the electronic control relay powers the fuel pump and your fuel injectors, it is essential to replace a faulty one. However, many other problems can present similar symptoms, so it’s very important to have the issue diagnosed by one of our expert mechanics.

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Excellent Rating

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Rating Summary
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5,188
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Robert

17 years of experience
28 reviews
Robert
17 years of experience
Mercedes-Benz 300SEL L6-3.0L - Drive Belt Tensioner - Newtown Square, Pennsylvania
Robert has a positive attitude and is very professional. He got my vintage (ancient?) Mercedes all patched up and running again. I would definitely recommend Robert without hesitation!

Jason

23 years of experience
190 reviews
Jason
23 years of experience
Mercedes-Benz GL550 V8-5.5L - Pre-purchase Car Inspection - Nashville, Tennessee
Jason did a great job with my pre-purchase inspection. He let me know when he was on his way, arrived on time, provided a detailed report, and answered any questions I had after the inspection was complete. I highly recommend Jason for anyone looking for a mobile mechanic to do a pre-purchase inspection.

Joseph

27 years of experience
578 reviews
Joseph
27 years of experience
Mercedes-Benz SLK280 V6-3.0L - Air Filter - Houston, Texas
Joseph was great! He was prompt and completed the work quickly! The expense was more than fair and much better than many places I've been to before. I've been and will continue recommending this service and him to everyone.

Robert

27 years of experience
333 reviews
Robert
27 years of experience
Mercedes-Benz C280 V6-2.8L - Heater Blower Motor - Laurel, Maryland
It was perfect.

Excellent Rating

(5,576)

Rating Summary
5,188
189
54
28
117
5,188
189
54
28
117
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