Technical Glow Plug Relay.
- Thread starter ninian324
- Start date
Currently reading:
Technical Glow Plug Relay.
Communicator
Prominent member
- Joined
- Aug 3, 2019
- Messages
- 2,086
- Points
- 562
My 2.8jtd does not have glowplugs in plural, only one for the flame starter, which may never have been used.
I cannot give a definitive answer, but sensible to pull the F02, (red) maxi blade fuse in engine bay fusebox. Also do not turn ignition on, with relay removed, as ECU will notice missing relay, and generate an alarm message.
- Joined
- Nov 3, 2014
- Messages
- 827
- Points
- 284
Hi
You don't say the age of your vehicle, but I have some knowledge of the setup for the X250 (2006 onwards). The glow plug "relay" is actually a combined electronic circuit board and a high current relay. The plastic case is bonded together, so contact cleaning is pretty well out of the question. I think it is extremely unlikely that dirty contacts are the cause of your problem, and relays are amongst the more reliable parts on modern vehicles. One of the jobs of the circuit board is to monitor the individual currents drawn by the four plugs, and if any one is too high or too low an error message will be generated. The later types will log an error code to indicate which plug is out of spec.
Have you checked that all the glow plugs are OK ? A simple check with an ohmmeter should show about 1 ohm from the plug "hot" terminal to the engine block (disconnect the harness first). The best glow plug testers use a realistic drive current, but this would normally be a garage job. Checking for stored error codes is also recommended.
One faulty plug will mean that the engine is a little rough for a few seconds after starting at very cold temperatures. Otherwise it will pass unnoticed.
You don't say the age of your vehicle, but I have some knowledge of the setup for the X250 (2006 onwards). The glow plug "relay" is actually a combined electronic circuit board and a high current relay. The plastic case is bonded together, so contact cleaning is pretty well out of the question. I think it is extremely unlikely that dirty contacts are the cause of your problem, and relays are amongst the more reliable parts on modern vehicles. One of the jobs of the circuit board is to monitor the individual currents drawn by the four plugs, and if any one is too high or too low an error message will be generated. The later types will log an error code to indicate which plug is out of spec.
Have you checked that all the glow plugs are OK ? A simple check with an ohmmeter should show about 1 ohm from the plug "hot" terminal to the engine block (disconnect the harness first). The best glow plug testers use a realistic drive current, but this would normally be a garage job. Checking for stored error codes is also recommended.
One faulty plug will mean that the engine is a little rough for a few seconds after starting at very cold temperatures. Otherwise it will pass unnoticed.
Communicator
Prominent member
- Joined
- Aug 3, 2019
- Messages
- 2,086
- Points
- 562
I would like to record my appreciation of the support, whether intentional or not, for my frequent statements in a similar vein.
- Joined
- Nov 3, 2014
- Messages
- 827
- Points
- 284
Hi
If the weather is warm enough, the glow plugs are not activated for starting. After a number of starts ( e.g 5 or 6 ) with no errors reported by the glow plug controller, the software will cancel the dashboard message. This doesn't affect any logged fault codes, which stay stored so that they can be read.
If the weather is warm enough, the glow plugs are not activated for starting. After a number of starts ( e.g 5 or 6 ) with no errors reported by the glow plug controller, the software will cancel the dashboard message. This doesn't affect any logged fault codes, which stay stored so that they can be read.
Thanks Anthony489 for the info, thats handy to know because I'm off to France and Spain shortly I was just worried that I may have problems with this fault. As you say I had the same problem possibly 7 or 8 months ago and it again disappeared. It only re-appeared when I had the van serviced for going on our trip and I asked the garage to check for any stored codes during the service and they reset this fault which has brought it back again. Hopefully after a few more starts and still not appearing it will put my mind at rest for going away on our trip. Thanks again.
