Description
Check part compatibility by using our vehicle filter options below. If you find your car, this part is compatible.
The glow plug control unit relay (OEM 12217786821) is a vital engine electrical component designed to regulate the electrical current supplied to the glow plugs on diesel-powered BMW vehicles. This relay works in conjunction with the vehicle’s engine control unit (ECU) to ensure each glow plug receives the correct power and timing during start-up, which is essential for efficient combustion and reliable cold starts. A failing or degraded relay can result in hard starts, long crank times, increased white smoke, and glow plug system warning lights. This replacement control unit is engineered to match the original BMW specification, providing dependable cold-start performance and helping maintain smooth engine operation in variable climates.
OEM Number: 12217788327, 12217801201, 7788327
Operating Mode : Electric
Voltage : 12V
Number of Cylinders : 6 for left-hand/right-hand drive vehicles
Number of connectors : 2
Number of Pins : 1+12
Quantity : 1
| Make | Model | Variant | Type | Engine | Chassis | Year |
|---|---|---|---|---|---|---|
| BMW | 3 Series | Diesel Convertible | 325d | 2993cc 145KW 197HP M57 D30 (306D3) | RWD — E93 | 2007-2010 |
| BMW | 3 Series | Diesel Convertible | 325d | 2993cc 155KW 211HP M57 D30 (306D3) | RWD — E93 | 2007-2010 |
| BMW | 3 Series | Diesel Convertible | 330Cd | 2993cc 150KW 204HP M57 D30 (306D2) | RWD — E46 | 2005-2007 |
| BMW | 3 Series | Diesel Convertible | 330d | 2993cc 170KW 231HP M57 D30 (306D3) | RWD — E93 | 2007-2013 |
| BMW | 3 Series | Diesel Coupe | 325d | 2993cc 145KW 197HP M57 D30 (306D3) | RWD — E92 | 2007-2010 |
| BMW | 3 Series | Diesel Coupe | 325d | 2993cc 155KW 211HP M57 D30 (306D3) | RWD — E92 | 2007-2010 |
| BMW | 3 Series | Diesel Coupe | 330Cd | 2993cc 150KW 204HP M57 D30 (306D2) | RWD — E46 | 2003-2006 |
| BMW | 3 Series | Diesel Coupe | 330d | 2993cc 170KW 231HP M57 D30 (306D3) | RWD — E92 | 2006-2008 |
| BMW | 3 Series | Diesel Coupe | 330xd | 2993cc 170KW 231HP M57 D30 (306D3) | AWD — E92 | 2006-2008 |
| BMW | 3 Series | Diesel Coupe | 335d | 2993cc 210KW 286HP M57 D30 (306D5) | RWD — E92 | 2006-2013 |
| BMW | 3 Series | Diesel Estate | 325d | 2993cc 145KW 197HP M57 D30 (306D3) | RWD — E91 | 2006-2012 |
| BMW | 3 Series | Diesel Estate | 330d | 2926cc 135KW 184HP M57 D30 (306D1) | RWD — E46 | 1999-2005 |
| BMW | 3 Series | Diesel Estate | 330d | 2993cc 150KW 204HP M57 D30 (306D2) | RWD — E46 | 2003-2005 |
| BMW | 3 Series | Diesel Estate | 330d | 2993cc 155KW 211HP M57 D30 (306D3);N57 D30 A | RWD — E91 | 2005-2012 |
| BMW | 3 Series | Diesel Estate | 330d | 2993cc 170KW 231HP M57 D30 (306D3) | RWD — E91 | 2004-2008 |
| BMW | 3 Series | Diesel Estate | 330xd | 2926cc 135KW 184HP M57 D30 (306D1) | AWD — E46 | 2000-2003 |
| BMW | 3 Series | Diesel Estate | 330xd | 2993cc 150KW 204HP M57 D30 (306D2) | AWD — E46 | 2002-2005 |
| BMW | 3 Series | Diesel Estate | 330xd | 2993cc 170KW 231HP M57 D30 (306D3) | AWD — E91 | 2005-2012 |
| BMW | 3 Series | Diesel Estate | 335d | 2993cc 210KW 286HP M57 D30 (306D5) | RWD — E91 | 2006-2012 |
| BMW | 3 Series | Diesel Saloon | 325d | 2993cc 145KW 197HP M57 D30 (306D3) | RWD — E90 | 2006-2010 |
| BMW | 3 Series | Diesel Saloon | 330d | 2926cc 135KW 184HP M57 D30 (306D1) | RWD — E46 | 1999-2005 |
| BMW | 3 Series | Diesel Saloon | 330d | 2993cc 150KW 204HP M57 D30 (306D2) | RWD — E46 | 2003-2005 |
| BMW | 3 Series | Diesel Saloon | 330d | 2993cc 155KW 211HP M57 D30 (306D3);N57 D30 A | RWD — E90 | 2005-2011 |
| BMW | 3 Series | Diesel Saloon | 330d | 2993cc 170KW 231HP M57 D30 (306D3) | RWD — E90 | 2005-2008 |
| BMW | 3 Series | Diesel Saloon | 330xd | 2926cc 135KW 184HP M57 D30 (306D1) | AWD — E46 | 2000-2003 |
| BMW | 3 Series | Diesel Saloon | 330xd | 2993cc 150KW 204HP M57 D30 (306D2) | AWD — E46 | 2002-2004 |
| BMW | 3 Series | Diesel Saloon | 330xd | 2993cc 170KW 231HP M57 D30 (306D3) | AWD — E90 | 2005-2008 |
| BMW | 3 Series | Diesel Saloon | 335d | 2993cc 210KW 286HP M57 D30 (306D5) | RWD — E90 | 2006-2011 |
| BMW | 5 Series | Diesel Estate | 525d | 2497cc 120KW 163HP M57 D25 (256D2) | RWD — E61 | 2004-2007 |
| BMW | 5 Series | Diesel Estate | 525d | 2497cc 130KW 177HP M57 D25 (256D2) | RWD — E61 | 2004-2007 |
| BMW | 5 Series | Diesel Estate | 525d | 2993cc 145KW 197HP M57 D30 (306D3) | RWD — E61 | 2007-2010 |
| BMW | 5 Series | Diesel Estate | 525d xDrive | 2993cc 145KW 197HP M57 D30 (306D3) | AWD — E61 | 2008-2010 |
| BMW | 5 Series | Diesel Estate | 525xd | 2993cc 145KW 197HP M57 D30 (306D3) | AWD — E61 | 2007-2008 |
| BMW | 5 Series | Diesel Estate | 530d | 2993cc 155KW 211HP M57 D30 (306D2);M57 D30 (306D3) | RWD — E61 | 2004-2010 |
| BMW | 5 Series | Diesel Estate | 530d | 2993cc 160KW 218HP M57 D30 (306D2) | RWD — E61 | 2004-2005 |
| BMW | 5 Series | Diesel Estate | 530d | 2993cc 170KW 231HP M57 D30 (306D3) | RWD — E61 | 2005-2007 |
| BMW | 5 Series | Diesel Estate | 530d | 2993cc 173KW 235HP M57 D30 (306D3) | RWD — E61 | 2007-2010 |
| BMW | 5 Series | Diesel Estate | 530d xDrive | 2993cc 173KW 235HP M57 D30 (306D3) | AWD — E61 | 2007-2010 |
| BMW | 5 Series | Diesel Estate | 530xd | 2993cc 170KW 231HP M57 D30 (306D3) | AWD — E61 | 2005-2007 |
| BMW | 5 Series | Diesel Estate | 530xd | 2993cc 173KW 235HP M57 D30 (306D3) | AWD — E61 | 2007-2007 |
| BMW | 5 Series | Diesel Estate | 535d | 2993cc 200KW 272HP M57 D30 (306D4) | RWD — E61 | 2004-2010 |
| BMW | 5 Series | Diesel Estate | 535d | 2993cc 210KW 286HP M57 D30 (306D5) | RWD — E61 | 2007-2010 |
| BMW | 5 Series | Diesel Saloon | 525d | 2497cc 120KW 163HP M57 D25 (256D2) | RWD — E60 | 2004-2010 |
| BMW | 5 Series | Diesel Saloon | 525d | 2497cc 130KW 177HP M57 D25 (256D2) | RWD — E60 | 2004-2010 |
| BMW | 5 Series | Diesel Saloon | 525d | 2993cc 145KW 197HP M57 D30 (306D3) | RWD — E60 | 2007-2010 |
| BMW | 5 Series | Diesel Saloon | 525d xDrive | 2993cc 145KW 197HP M57 D30 (306D3) | AWD — E60 | 2008-2009 |
| BMW | 5 Series | Diesel Saloon | 525xd | 2993cc 145KW 197HP M57 D30 (306D3) | AWD — E60 | 2007-2008 |
| BMW | 5 Series | Diesel Saloon | 530d | 2993cc 155KW 211HP M57 D30 (306D2);M57 D30 (306D3) | RWD — E60 | 2002-2009 |
| BMW | 5 Series | Diesel Saloon | 530d | 2993cc 160KW 218HP M57 D30 (306D2) | RWD — E60 | 2002-2005 |
| BMW | 5 Series | Diesel Saloon | 530d | 2993cc 170KW 231HP M57 D30 (306D3) | RWD — E60 | 2005-2007 |
| BMW | 5 Series | Diesel Saloon | 530d | 2993cc 173KW 235HP M57 D30 (306D3) | RWD — E60 | 2007-2009 |
| BMW | 5 Series | Diesel Saloon | 530d xDrive | 2993cc 173KW 235HP M57 D30 (306D3) | AWD — E60 | 2007-2009 |
| BMW | 5 Series | Diesel Saloon | 530xd | 2993cc 170KW 231HP M57 D30 (306D3) | AWD — E60 | 2005-2007 |
| BMW | 5 Series | Diesel Saloon | 530xd | 2993cc 173KW 235HP M57 D30 (306D3) | AWD — E60 | 2007-2007 |
| BMW | 5 Series | Diesel Saloon | 535d | 2993cc 200KW 272HP M57 D30 (306D4) | RWD — E60 | 2004-2010 |
| BMW | 5 Series | Diesel Saloon | 535d | 2993cc 210KW 286HP M57 D30 (306D5) | RWD — E60 | 2007-2010 |
| BMW | 6 Series | Diesel Convertible | 635d | 2993cc 210KW 286HP M57 D30 (306D5) | RWD — E64 | 2007-2010 |
| BMW | 6 Series | Diesel Coupe | 635d | 2993cc 210KW 286HP M57 D30 (306D5) | RWD — E63 | 2007-2010 |
| BMW | 7 Series | Diesel Saloon | 730d | 2993cc 155KW 211HP M57 D30 (306D2);M57 D30 (306D3) | RWD — E65,E66,E67 | 2003-2008 |
| BMW | 7 Series | Diesel Saloon | 730d | 2993cc 160KW 218HP M57 D30 (306D2) | RWD — E65,E66,E67 | 2002-2005 |
| BMW | 7 Series | Diesel Saloon | 730Ld | 2993cc 170KW 231HP M57 D30 (306D3) | RWD — E65,E66,E67 | 2005-2008 |
| BMW | X3 | Diesel SUV | 3.0d | 2993cc 150KW 204HP M57 D30 (306D2) | AWD — E83 | 2004-2005 |
| BMW | X3 | Diesel SUV | 3.0d | 2993cc 160KW 218HP M57 D30 (306D3) | AWD — E83 | 2005-2008 |
| BMW | X3 | Diesel SUV | 3.0sd | 2993cc 210KW 286HP M57 D30 (306D5) | AWD — E83 | 2006-2008 |
| BMW | X3 | Diesel SUV | 30d xDrive | 2993cc 155KW 211HP M57 D30 (306D3) | AWD — E83 | 2008-2010 |
| BMW | X3 | Diesel SUV | 30d xDrive | 2993cc 160KW 218HP M57 D30 (306D3) | AWD — E83 | 2008-2010 |
| BMW | X3 | Diesel SUV | 35d xDrive | 2993cc 210KW 286HP M57 D30 (306D5) | AWD — E83 | 2008-2011 |
| BMW | X5 | Diesel SUV | 3.0 3.0d | 2993cc 155KW 211HP M57 D30 (306D3) | AWD — E70 | 2007-2008 |
| BMW | X5 | Diesel SUV | 3.0d | 2925cc 135KW 184HP M57 D30 (306D1) | AWD — E53 | 2001-2003 |
| BMW | X5 | Diesel SUV | 3.0d | 2993cc 155KW 211HP M57 D30 (306D2) | AWD — E53 | 2003-2006 |
| BMW | X5 | Diesel SUV | 3.0d | 2993cc 160KW 218HP M57 D30 (306D2) | AWD — E53 | 2003-2006 |
| BMW | X5 | Diesel SUV | 3.0d | 2993cc 173KW 235HP M57 D30 (306D3) | AWD — E70 | 2006-2008 |
| BMW | X5 | Diesel SUV | 3.0sd | 2993cc 210KW 286HP M57 D30 (306D5) | AWD — E70 | 2007-2008 |
| BMW | X5 | Diesel SUV | 30d xDrive | 2993cc 155KW 211HP M57 D30 (306D3);N57 D30 A | AWD — E70 | 2008-2013 |
| BMW | X5 | Diesel SUV | 30d xDrive | 2993cc 173KW 235HP M57 D30 (306D3) | AWD — E70 | 2008-2010 |
| BMW | X5 | Diesel SUV | 35d xDrive | 2993cc 210KW 286HP M57 D30 (306D5) | AWD — E70 | 2008-2013 |
| BMW | X6 | Diesel SUV | 30d xDrive | 2993cc 173KW 235HP M57 D30 (306D3) | AWD — E71,E72 | 2008-2010 |
| BMW | X6 | Diesel SUV | 35d xDrive | 2993cc 210KW 286HP M57 D30 (306D5) | AWD — E71,E72 | 2008-2010 |
| Make | Model | Variant | Type | Engine | Chassis | Year |
Our SKU: TB12217801201_313
All our Glow Plug Control Unit Relay For BMW 12217786821 are OEM quality and reliable after market car parts. This Glow Plug Control Unit Relay For BMW 12217786821 is specifically compatible with BMW: 3 Series, 5 Series, 6 Series, 7 Series, X3, X5, X6, .
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
Regulates Glow Plug Electrical Current Precisely
The relay ensures glow plugs receive consistent and correct current based on ECU signals, supporting effective pre-heating of combustion chambers for optimal starting performance.
Restores Cold-Start Reliability
Replacing a faulty or worn glow plug control unit can significantly improve engine start-up behaviour, particularly in colder conditions where proper pre-heating is critical.
Direct OEM Replacement (12217786821)
Manufactured to meet BMW’s original specifications, this relay fits directly in place of the original unit with OEM reference 12217786821 and requires no modification for correct installation.
Supports Diesel Combustion Efficiency
Reliable glow plug control helps promote smoother combustion immediately after start-up, which can improve fuel efficiency, reduce white smoke emissions, and support overall engine performance.
Compatible with Multiple BMW Models
This relay is commonly used on diesel BMW models equipped with engines requiring part number 12217786821, including various 1 Series, 3 Series, and X-Series vehicles. Always confirm OEM part fitment using your VIN or existing component reference.
Frequently Asked Questions (FAQs)
Q: What does a glow plug control unit relay do?
A glow plug control unit relay manages the electrical current and timing delivered to the glow plugs during engine start-up, enabling effective pre-heating of cylinders to ensure smooth diesel ignition.
Q: What are common symptoms of a failing glow plug relay?
Typical signs include difficulty starting the engine, long crank times (especially in cold weather), glow plug warning lights or engine warning lights on the dashboard, rough idle after start-up, and increased white smoke from the exhaust.
Q: Which vehicles use part number 12217786821?
Part number 12217786821 is used on a range of BMW diesel models — often within 1 Series, 3 Series, X1, X3 and other vehicles equipped with certain 4-cylinder diesel engines. Always check compatibility with your specific VIN or existing part number.
Q: Is this a direct replacement part?
Yes. This glow plug control unit relay is designed as a direct OEM replacement for the original 12217786821 relay and installs without modification when matched to the correct application.
Q: Should I replace glow plugs at the same time?
It is good practice to inspect the glow plugs and related wiring when servicing the relay, as worn glow plugs or poor wiring connections can contribute to cold-start issues even if the relay is functioning correctly.
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