Help! Td5 Diagnostic fault codes and starting issue when cold.

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.

Chalky.

Well-Known Member
Posts
4,714
Location
Mid Wales
Hi guys!
This is not a desperate problem, as it is one I have only in the winter months, but I thought I should probably sort it this summer/autumn so I don't get it again.

I bought a Lynx diagnostic tool a while back, and did the usual clearing old codes, driving, and no fault codes came back except the usual a/c etc that all td5's seem to get.

Until.....i was trying to start it on a cold morning, the engine cranked over but not fast enough to start, I let the glowplugs heat and and go out twice before trying again, same issue. So I did it again, this time with a touch of throttle and it started! Each time it gets down to about 4 degrees and below, I have to give it some blips from the throttle to get it to start, and whilst it does always start in this way its not right.

I plugged the Lynx in to see if anything had changed, and I got two new fault codes that I hadn't had before the cranking in cold issue;
3070: Glowplug Lamp Drive Open load logged, and
3071: Glowplug Relay Drive Open load logged.

I have done some searching on he subject of these two particular codes, but have come across no definitive answers.

I immediately presumed replacing glow plugs was a solution, but read the same query as mine and someone had replaced with no noticeable difference. The battery is good, and the vehicle starts spot on all year round ( its my daily driver) and its something to do with cold weather starting and the glowplugs, hence the codes.

If anyone can help that would be wonderful! Thanks in advance! J
 
Hi I would try replacing the glow plug relay and fuel pump relay and glow plugs

Although a good td5 doesn't really need glow plugs it's better to have working ones... Before spending to much I would do a compression test
 
Hi mate, why would you replace the fuel pump relay? I'm driving every day and its absolutely spot on, no probe with fuel delivery at all.

Good shout on the glowplug relay, and ill do the plugs as a matter of course as the beauty is 18 years old and I'm doubtful they'll of been changed.

Also why do you recommend a compression test? I pull a loaded trailer most days and it pulls like a train without fault and no blue smoke or anything, I think the rings are good and I uses no oil at all, it has no other faults apart from when the outside temperature drops......
 
Last edited:
I'd go with the glow-plug relay too.
If the ECU is anything like the Disco 2, the little tell-tale light on the dashboard just indicates that the circuit is operating, not that there's power applied to the glow-plugs.
I'd try to keep an eye on the battery voltage during the cold weather too. On the Disco 2, the ECU likes at least 10.5 volts while the engine is cranking for it to work and the engine fire up. In cold weather the battery can show poor performance particularly due to age much more readily than in warmer weather.
 
Last edited:
I'd go with the glow-plug relay too.
If the ECU is anything like the Disco 2, the little tell-tale light on the dashboard just indicates that the circuit is operating, not that there's power applied to the glow-plugs.
I'd try to keep an eye on the battery voltage during the cold weather too. On the Disco 2, the ECU likes at least 10.5 volts while the engine is cranking for it to work and the engine fire up. In cold weather the battery can show poor performance particularly due to age much more readily than in warmer weather.

Thanks for the input mate! I'm sure I did a live test with the Lynx and battery voltage was 13 something, although ill certainly keep an eye!

Relay is the first thing ill do when I get home!
 
@sierrafery Hi mate, I was hoping you might pop along! ;)

Red plug is clear, I replaced injector loom as a first job when I bought it over two years ago, and I fairly regularly take the red plug off and squirt brake cleaner in and let dry, just to get the last vestiges of oil out from before I owned it.

Do you have any clue as to what the two fault codes actually diagnose bud? Thanks!
 
3070: Glowplug Lamp Drive Open load logged, and
3071: Glowplug Relay Drive Open load logged.
Hi m8, 3070 was an interruption betweeen the ECU and the glow plug warning lamp circuit , 3071 contact lost on the relay's coil earth path from the ECU, both can be the result of a momentary voltage drop after ignition if they dont come back ... you should be able to check the circuits with Lynx as to activate the lamp and the relay for test.... better dont play with the throttle while cranking cos you might hydrolock it, next time it does hard starting the trick let the ignition on II and let it so untill the pump stops then crank it without any throttle...if it starts this way fast we'll speak then
 
Hi m8, 3070 was an interruption betweeen the ECU and the glow plug warning lamp circuit , 3071 contact lost on the relay's coil earth path from the ECU, both can be the result of a momentary voltage drop after ignition if they dont come back ... you should be able to check the circuits with Lynx as to activate the lamp and the relay for test.... better dont play with the throttle while cranking cos you might hydrolock it, next time it does hard starting the trick let the ignition on II and let it so untill the pump stops then crank it without any throttle...if it starts this way fast we'll speak then

Thankyou very much matey! Greatly appreciated! :)
 
Hi as ferry said please don't touch the throttle when starting her just keep swinging on the Motor...

I'm interested in this thread as my old discovery td5 used to do this but never solved the problem
 
How would it hydrolock?

Cheers
With unburnt fuel in the cylinders if it cranks much with throttle depressed and doesnt start.... it's not recommended to crank a Td5 with throttle depressed as long as there's not certain that air got into the rail or it ran out of fuel
 
Hi m8, 3070 was an interruption betweeen the ECU and the glow plug warning lamp circuit , 3071 contact lost on the relay's coil earth path from the ECU, both can be the result of a momentary voltage drop after ignition if they dont come back ... you should be able to check the circuits with Lynx as to activate the lamp and the relay for test.... better dont play with the throttle while cranking cos you might hydrolock it, next time it does hard starting the trick let the ignition on II and let it so untill the pump stops then crank it without any throttle...if it starts this way fast we'll speak then

Hi Mate! Had our first frost this morning so was able to try out what you suggested I.e. Turning the ignition to II and waiting until the pump stops make a whirring noise, it then started first turn of the key without any throttle! Sounded a little lumpy but absolutely fine in evey other respect!
 
Hi guys, for anyone that's interested I thought id write up what's happened so far.....

First frosty start, I let the pump prime all the way through until the humming stopped turned the key and she did fire, but quite lumpy.

Next cold morning it took 3 turns of letting plugs glow and turning to II on the ignition whilst waiting for pump noise to stop until she fired.

Decided enough was enough and have a delve around to see what's going on, pulled the glow plug connectors off, took each plug out and tested on a battery, all glowed up hot fairly quickly and were fine, not the glowplugs themselves then.....

Next stuck probe into end of connectors, and checked each one with the ignition on a coil light lit up, not one had power going to it.

Lifted drivers seat to reveal fuses and relays, checked the 100 amp fuse with electric screwdriver and clamp, that was fine. Next to check were the relays, (I only have two as I don't have aircon), one is ecu main relay (yellow), the other is glowplug relay (black), I wasn't sure which one was which, so I you look at wires entering relay, there is a very thick yellow wire going to the glowplug relay (or you can turn ignition on and pull one of them out, if pump stops, its the other one :) ).

Checked with a probe the electric was entering the relay, it was. So I took the relay out, and then opened it up, it smelt badly of burnt electric and you could see the switch had melted the plastic where it makes contact when relay is operated.

I've ordered a new relay, and have trimmed plastic and bent switch so it will make a better contact and last me the rest of the week until new one arrives.

Hopefully, this will cure the issue, will report back either way! Cheers for the pointers along the way.
 
Just to report back, it was the glowplug relay! Have a Britpart one in now that's working, time will tell for how long for! ;)

Thanks all!
 
Back
Top