V300Graham

Hello,

Have you any suggestions as to why my 2002 SC430 didn't start this evening ?

The engine turns over as normal, I can smell the unburnt fuel out the exhaust. I can hear the fuel pump working etc. It gives a slight cough upon first turn of the key but will not come near firing up properly. The engine turns over at speed from the starter but without any further signs of ignition.
The car's key is unlocking the car with the remote on the key as normal so I don't think it's an immmobiliser issue. The battery is fully charged and turned the engine over for about 5 minutes in total during the hour I tried to start her in so there is no battery voltage problem.

A strong side issue is that the heater fan started to switch on and off by itself yesterday, and this morning stopped altogether on the drive home. Another thing is that the heater fan briefly turns for one tenth of a second of so when switching the car off, even when selected to off on the climate control screen.

I disconnected the battery, pulled out the ECU to check for visible problems on the connectors like corrosion, damp etc but found none. The earth straps in the engine area all seem good, all fuses seem good too. I've pulled and re-installed all the visable engine bay fuses, but nothing improved. No big fuses are blown that I can see. The cars remains a non-starter and the heater fan still won't operate as normal.

Lastly, the boot / trunk area seems to be quite damp so I let it open for a while to dry out tonight.

Stuff like this is not supposed to happen to a Lexus !!

DarthSid

Aside your car not starting, I would investigate why the trunk area is damp. Is the cab area experiencing a moister problem as well?

V300Graham

DarthSid, the car gets a bit damp as the roof seals and the boot / trunk seals seem to be a bit crushed with her 12 years of age. She dries out with regular driving, but she was parked up for 6 wet days in Birmingham in England this last week. I've yet to see a convertible that is drum tight in all weathers and my Merc cabrio too lets in some water when the weather turns windy and wet, but I think it's time to address this issue in the Lexus.

Now I found elsewhere after a bit of searching primarly on Clublexus in the LS430 section that the fuel pump relay will give the starting symptoms I've described, so I think I'll replace that first, but I'm still at a loss to find a cause of the heater blower fans erratic behaviour and I'm still suspicious that both issues are connected....

EDIT found these part number for a Fan Blower control module: 87165-22050. and this for the fuel pump relay: 90987-03003.

I'll still suspicious that both items are related to some common point as it's like lightning striking twice for the starting and blower issue to happen within 24 hours of each other.
The threads I've searched say otherwise, though lets see.

I'll update you all when I've changed the fuel pump relay and the fan blower control module too. Time to order some parts !

JohnnyCake

I vote ignition issue.

I'm not sure that the registration for the lock/unlock, is the same for the immobilizer. Anyone know?

bacardi11

iTrader: (1)

I agree with JohnnyCake ignition problem your getting no spark to fire the engine.

FLYCT

Different computers. Immobilizer and door lock/unlock.

Just because a key remote will unlock a door does not mean there isn't an immobilizer issue. It could be the cars immobilizer electronics or just a bad key.

I suggest that before going nuts the original poster try using another key to is if the engine fires up.

V300Graham

Hi guys, that key has always worked normally for 3 years now and I've never ever had an issue like this before not even for a second. I don't think it's the key. As an aside I've only one key for this car since I've had it.... but it's as good a suggestion as any, and will be investigated in due course. The car does provide spark, but not for long enough to fire up the engine. It sparks for less than 1/2 a second and then stops again. The red flashing led for the immobilizer goes out like normal when the key is put into the ignition and turned. Thank you for all replies thus far Gents.

My own feeling is that I have an earthing point or a relay somewhere not functioning normally. Second guess is fuel pump, relay, pressure regulator, etc. I've no tooling to be able to confirm any of this.

I got a loan of a scan tool and there are no fault codes detectable by this tool stored in the ECU, I checked with those 10 dollar OBDII tools along with the "Torque" app. The ECU seemed to communicate well with the scan tool though I have my doubts that it actually communicated at all.

I brought the battery close to discharged this morning after all the cranking attempts since last night and a the few more this morning, so it's charging up now with a battery charger, with the battery earth strap disconnected.

At this point I feel a trip on a tow truck to an independent Lexus service centre is due now.
I've checked all the easy stuff at this stage. It's not helped by the fact that I'm currently in England but am normally resident in Ireland and I've no contacts over here.

Picture of her getting charged up this morning.


https://i.imgur.com/L6e8K3A.jpg

V300Graham

I had the battery disconnected today, and put it back on in the evening, opened and closed the doors with the button on the key no problem, and she fires up and runs properly.
As a bonus the heater fan relay thingy is working normally too, so full normal service resumed !

I had the boot open all day as it seemed a bit damp yesterday, and I had pulled and reseated all the fuses in the engine bay again this morning, so I suppose (and I hope) I'll never find out what exactly happened. I'm somewhat suspicious of my key now and will get another Master Key from the dealer ASAP.

Pic of my full engine bay with the engine cover off.


https://i.imgur.com/4rcGDzil.jpg

JohnnyCake

We were all probably amiss not to suggest that. ECU reset.

V300Graham

Thanks for all the speedy replies guys, especially over a weekend.

Harold57

Don't rule out a low battery either. You did charge up the battery. If it happens again, check your battery voltage as you crank it or turn your lights on and see whether it holds a proper voltage under the load. Or just go and have the battery load tested. (I think that I'd have it load tested regardless.) A low battery makes today's cars do all sorts of crazy things.

wmleach

I had the same or similar problem. Technically for me, it's a delay in the engine turning over. When I say turning over, I mean actually starting. The first time it happened was 7/16 and took 4 times of turning the key over for the engine to start but it did. Even though it started, I thought it was the battery and was getting an oil change so had the battery tested. Tested bad so Lexus replaced it on 7/17 and new terminals.

7/18 it continues to do it. It starts, but it's like a delay. When you turn the key, you hear a click - delay - then it starts. Suffice it to say, I apparently purchased a battery I did not need. I've had the car for 3.5 years and this has never happened. No check engine light.

I did hear a humming noise coming from the back area of the car on the driver's side. Any and all suggestions are welcomed - stumped and don't want to play the process of elimination game with the dealers.

It's a 2002 with 87,400 miles.

pynky01

Remember Occam's Razor....a principle of parsimony, economy, or succinctness used in problem-solving ...always start with the simplest thing first...in this case it may be the key or reset ECU...but i learned in the army...kiss...keep it simple stupid (talkin to us grunts as cannon fodder)...good luck and keep us posted...