BMW 840Ci ECM-Power Relay Replacement at your home or office.

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ECM-Power Relay Replacement Service

How much does a ECM-Power Relay Replacement cost?

On average, the cost for a BMW 840Ci ECM-Power Relay Replacement is $126 with $31 for parts and $95 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
1996 BMW 840CiV8-4.4LService typeECM-Power Relay ReplacementEstimate$177.35Shop/Dealer Price$210.44 - $270.34
1994 BMW 840CiV8-4.0LService typeECM-Power Relay ReplacementEstimate$193.35Shop/Dealer Price$235.47 - $322.39
1997 BMW 840CiV8-4.4LService typeECM-Power Relay ReplacementEstimate$157.35Shop/Dealer Price$190.47 - $250.39
1995 BMW 840CiV8-4.0LService typeECM-Power Relay ReplacementEstimate$193.35Shop/Dealer Price$235.43 - $322.32
Show example BMW 840Ci ECM-Power Relay Replacement prices

What is the ECM-Power Relay all about?

Vehicle development has evolved over the past several decades to a point where it seems every vehicle function is controlled by a computer, right down to the engine itself. This is actually the case for the engine and its related functions as it is controlled by the engine control module, or ECM. The ECM monitors and adjusts operation and power distribution to the fuel supply and injection systems, engine timing, exhaust gas recirculation, emissions, ignition system, and several other systems. In order to dispense power to operate these other systems, the engine control module requires power itself.

The power distribution center, or fuse block, located under the hood houses most or all of the vehicle’s fuses and relays. It contains a relay for the ECM that is powered up when the ignition key is turned to the on position. This ECM power relay acts as a switch that supplies power to the ECM. When the ignition is turned off, power switches inside the ECM relay and it no longer receives battery power. If the ECM power relay stops switching as it should, you will experience vehicle problems. When the relay is stuck open, no power will be delivered to the engine control module and the vehicle won’t start. If the relay is stuck closed, constant power will be sent to the ECM even with the engine turned off and the battery will drain.

Keep in mind:

  • The battery should be disconnected any time the electrical system is being serviced.
  • There are several problems which can cause your vehicle not to start, with the ECM power relay being one of them. Have the problem diagnosed by one of our expert technicians.

How it's done:

  • The ECM-power relay is verified that it needs to be replaced. The relay is located in the engine main fuse relay control box.

  • The defective ECM-power relay is removed from the control box by pulling it straight up and out of socket.

  • The new ECM-power relay is installed into the socket and the engine scanned for codes.

  • The engine is started and the ECM-power relay is tested for proper operation.

  • The vehicle is road tested for proper operation of the ECM-power relay and is then checked for codes.

Our recommendation:

The ECM power relay should last the lifetime of your vehicle unless there is a power distribution problem or moisture that causes it to fail. If your vehicle won’t start, have one of our expert technicians diagnose the problem and replace the ECM power relay if necessary.

What common symptoms indicate you may need to replace the ECM-Power Relay?

  • Engine will not start when the key is turned.
  • Engine doesn’t turn over when ignition is on.
  • Check Engine light is on.
  • Battery drain which may leave it weak or dead.

How important is this service?

Although it is extremely unlikely the ECM relay will cause your vehicle to stall or create a safety concern, your vehicle may not start or the battery may die while the ignition is off. In either case, you will need to replace the ECM relay.

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Adam

17 years of experience
231 reviews
Adam
17 years of experience
BMW 840Ci V8-4.4L - Car is not starting - Boynton Beach, Florida
Adam was great. He was on-time and had to wait because of a stupid HOA rule. He got the car started again recommended a good charger, and was extremely through in his inspection that identified a couple problem with the oil caps that need to be replaced. I highly recommend Adam and plan n using him again when i receive the quote for the recommended services.

Jeremy

20 years of experience
603 reviews
Jeremy
20 years of experience
BMW 840Ci V8-4.4L - Battery - Boynton Beach, Florida
On time, nice guy, always does a good job. I will be in touch with him and YourMechanic.com again in the near future. Thanks again!

Joshua

27 years of experience
709 reviews
Joshua
27 years of experience
BMW 325xi L6-3.0L - Car overheats quickly - Oakland, California
On time and very knowledgable

Peter

43 years of experience
1321 reviews
Peter
43 years of experience
BMW 320i L4-2.0L Turbo - Car is not starting - Buckeye, Arizona
Solid and very professional work. Honost advice on service required. 100% recommend Peter to anyone.

Excellent Rating

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Rating Summary
6,192
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6,192
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142
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