Recently starting has been intermittent on my 2009 2.0 TDCi S Max, whereby it turns over but doesn't fire. It appears that waiting for a loudish relay click facilitates the car to start "on the button". I have so far checked and changed R1, R2 & R4 relays and I've cleaned various cable plugs and terminals, although they all look clean and the relays seem to be clicking OK, but the problem remains and it is getting worse.

There are two reddish-brown, hard plastic looking components connected to the engine on the gearbox side. I cannot remember what their function or component names. could it be these? I ask because I remember a question a long time ago that these may prevent starting???

Does anyone have suggestions to try?

Many thanks in advance.

OTTO.

On 11/15/2024 at 2:19 PM, Ottophile said:

2.0 TDCi S Max, whereby it turns over but doesn't fire. It appears that waiting for a loudish relay click facilitates the car to start "on the button".

You have an old diesel engine. You have to wait for the glow plugs to heat up before trying to start the engine.

Turn on ignition, wait until the glow plug light goes off (relay clicks) and the start the engine.

the 2 brown things you mentioned are boost solenoids, they wont prevent starting, one controls the anti shudder valve and the other the turbo wastegate if i remember...

does it turn over slower? or crank a while before firing?

i recently had similar, and it was the starter motor

SWEARWOLF,

Thank you for your reply and useful info.

The starter turns fast and doesn't slow-up. It's an intermittent ignition issue, which seems to be something to do with relay switching, or something that controls relay switching?

 

UNOFIX,

Thank you for your reply.

The car is old, but I've owned it from new and covered only 43000 miles.

I have rarely needed to wait for the glow plugs light to go out. It normally starts immediately, in all weather, until this recent intermittent issue. When this occurs I wait for the glow plug light to cycle off. However, if it starts without this issue, it fires immediately, as usual.

• The main issue is that sometimes it won't fire;
• then I switch ignition off and wait a minute, until...
• I hear a relay click (this while sitting in the car);
• then I try to start it, but it doesn't always start at this point. Then I wait a while for a distinctively louder relay click (ignition off), possibly from two relays clicking simultaneously;
• Then it starts immediately.

 

My opinion, there's no "ignition" as such. If there's good compression and enough fuel is being injected at the correct time and enough pressure plus there's enough heat in the cylinder via the glow plugs, although direct injection engines need less than the old indirect "Ricardo swirl chamber type" (showing my age there!) there should be some reaction/misfiring/white smoke, whatever. If it's turning normally but completely dead I suspect fuel (always difficult to do at a distance however?)

I don't fully understand your clicking sequences especially when clicks are happening with ignition OFF?

As mentioned above, suggest checking power to and resistance of glow plugs because you say "recently" i.e. it has got a bit colder AND, in parallel, with fuel and and electrical issues below.

From what I read, I'd ask if you have checked that there are no air bubbles in the fuel line and the filter is clear, just change it?

Whilst it may not be electrical, but you know your car better than me, I'd find out exactly which relays are responsible for what from the handbook and consider removing each in turn to observe the effect and find the ones that produce the specific clicks you mention then report back after all of that. I am unsure if a standard relay (small box) would produce the big click you mention I never hear any relays clicking unless the bonnet is open and certainly not from the driving seat. The biggest click could come from the solenoid on the starter and if it doesn't spin, that's the only time you'd hear it (in my opinion?)

AFAIK, the brown devices are controllers (as said) there may be a double one (turbo vanes and EGR valve, perhaps) and  I can't remember the function of the other. They work on a PCM signal which modulates a vacuum signal that is transferred to the actuator on the device it is connected to. You'll need to look at that as well?

Consider all of the above and come back with some results?

SWEARWOLF,

Thank you for your reply and useful info.

The starter turns fast and doesn't slow-up. It's an intermittent ignition issue, which seems to be something to do with relay switching, or something that controls relay switching?

 

UNOFIX,

Thank you for your reply.

The car is old, but I've owned it from new and covered only 43000 miles.

I have rarely needed to wait for the glow plugs light to go out. It normally starts immediately, in all weather, until this recent intermittent issue. When this occurs I wait for the glow plug light to cycle off. However, if it starts without this issue, it fires immediately, as usual.

• The main issue is that sometimes it won't fire;
• then I switch ignition off and wait a minute, until...
• I hear a relay click (this while sitting in the car);
• then I try to start it, but it doesn't always start at this point. Then I wait a while for a distinctively louder relay click (ignition off), possibly from two relays clicking simultaneously;
• Then it starts immediately.

 

Thank you Shearers for your helpful reply.

You mention the PCM controls the solenoids to modulate a vacuum signal. Do you know if the PCM controls the engine start relays? In other words, is it feasible to suggest the PCM may be responsible for the intermittent starting?

The intermittent starting occurred today. I removed the cover protecting the relays and some fuses and after a minute or two I heard the distinctive click (sounds like a sticky bi-metal strip suddenly clicking-in or perhaps out). There are several relays close together, so identifying which one it was was unachievable. The key was in the ignition (switched-off). I quickly turned the key and it started immediately (1/2 to 1 turn on the very strong starter motor).

My problem is, how to diagnose such an intermittent relay, particularly if it is another faulty module controlling it?

Any help gratefully received.

On 11/25/2024 at 11:57 AM, Ottophile said:

The main issue is that sometimes it won't fire;

Can I just check with you on this, encase I'm not understanding the problem.

When you say "it won't fire" is the starter motor still cranking the engine ?

In addition to @unofix question I still refer to my comments above on finding out which relays do what (even removing each one in turn to actually see the effect or ideally test them or swap IDENTICAL ones (keeping a careful note and numbering each one so they can be replaced)
There are relays that operate when the "ignition" is turned on and others that operate under control of the PCM and other control elements?

But that's just what I'd do to rule that out if it's definitely the relays in that fuse box clicking as this is a strange fault (aren't they all!)

Thank you Unofix for your reply,

The starter motor turns very strong i.e. if the intermittent fault/issue doesn't occur it will start on about half a turn (immediate,  glow plugs not normally required). When the intermittent fault occurs it has no chance of starting/firing, after which about 1-2 minutes (ignition off) I sometimes hear a loud relay click (possibly 2 relays at the same time), then it starts immediately (less than one full turnover). However, sometimes there is a relay-type click that is a quieter click (perhaps just one relay), which turns over, but will not start. It's unlikely to be a weak starter motor, as mine seems to turn vigorously (as new?). 

 

Thank you Shearers for your reply,

I've swapped Relays for the engine side, as follows and described by the printed plan on the under-side of the relays cover to N/S of the engine compartment: R1 swapped; R2 swapped and R3 swapped, all with no change, although because it's intermittent I have to wait until failure, which could take up to a week (5-10 Starts), or so.

Any help gratefully received. Thanks guys.

Oops. Shearers, 

Meant to say i've swapped R1, R2 & R4 relays. These are the larger grey relays. i've not tried RR3, as it's a smaller black-coloured relay and doesn't seem to be part of the starting protocol, but I could be wrong!

The missing link as far as I can see, is what each relay does and, most importantly, what on Earth is the actual source of the two types of click that you describe, if it's not one or more of the relays in that fuse box?

Only thing I can think of at present is to find what each relay actually covers then leave them (the relevant ones - related to starting, or perhaps not?) out in turn to see if you can duplicate the 2 effects you describe (turn normally but no start and not turn at all)

You appear to know the exact conditions: start, turn over but no start and no turn over, but not the exact device(s) doing the clicking. That seems to be the root of the problem?

Loud clicks wouldn't seem to be caused by any relays in the fuse box which brings me back to the solenoid in the starter and the starter itself or some wiring fault/earth lead but that is not what you appear to be reporting as you seem to be saying that is is centred on that fuse box - this really seems to be the nub of the problem - what is actually doing the clicking???

My info says the function of the relays is on the fusebox lid?

Especially confusing is the clicking with "ignition" off??

Like you, I'm rather confused?

Edit: On a wiring diagram I have there is R6 (Starter) and R75 (?) "Terminal 15 voltage supply - a bit suspicious that there are 2 shown on the starting system but it could be completely different on your model?

4 hours ago, Ottophile said:

I sometimes hear a loud relay click (possibly 2 relays at the same time), then it starts immediately (less than one full turnover).

From what you are describing I would suspect that Relay 2 Powetrain Control Module (PCM) is not been turned on for some reason. I don't think that any of the relays are themself actually faulty, only that they are not been energised at the correct time.

You could for test purposes remove Relay 2 and fit a link between terminal 3 and 5 (see green on diagram below). This will cause the PCM to be constantly on. Then see if the starting problem is resolved.

From @unofix post, R7 (don't know why  it's named R75 but it mentions Terminal 15?) matches with my wiring diagram and is connected with the starting circuit?

However there's an obvious difference between my R6 and your diagram - what is on the fusebox lid?

Does bridging the relay rule out  a wiring fault between relay and PCM (how do we know that PCM is definitely ON  (Forscan detects modules that are online)?

It looks like "we" may be getting closer (sorry if my excitement is showing)?

According to Diagnose Dan: "Terminal 15" appears to be a generic term for "ignition circuit" (which matches my wiring diagram)