Preheater Light

[Guest JonathanK]

The preheater light on my 110TDi started flashing yesterday indicating a fault in the diesel engine management somewhere.

 

Anyone know what the cause might be and whether a non Ford/Seat/VW dealer can interrogate the system?

 

Thanks

 

Jon K

[Ivor_E_Tower]

Does it flash all the time? Not found anything in the TIS CD on this, and mine flashed on-and-off for a few seconds last month on one occasion only,

so I'd be interested in knowing what it means too.

[Guest JonathanK]

Comes on after about 20 seconds and stays flashing. I'm going to get it looked at this week and will post the remedy, providing they can find it.

 

JK

[Dodger]

Check the brake lights are working. This can be caused by a faulty brake light switch.

[Guest JonathanK]

Dodger

 

You are a diamond, geezer.

 

I changed a faulty brake light last Thursday and the problem occurred on Saturday. Checked it our after your posting and you're right - no brake lights.

 

Guess I'll check the switch now and see what happens.

 

Thanks again.

 

JK

[Dodger]

Only too pleased to share my experience.

 

In my case the switch itself was not faulty but had moved on its mounting. I think it is a very common problem.

[Guest JonathanK]

Good news (for me). Pushed the brake pedal down and then flicked the brake light switch a few times, just to make sure there was a good contact, and the problem went away.

 

Brake lights work, flashing lamp on dash gone out without needing to reset ECU or disconnect battery.

 

Thanks again to Dodger. Proof positive that a site like this can save you money.

 

JK

[kevinp]

Interesting stuff. Looking back in detail last night through my Ford service history for my '98 Tdi (I've only had the car for 2 months), I note it went in earlier this year for the engine management light flashing. Fault found - new brake light switch fitted, cured problem.

[Guest reefer]

Seems brake lighht switch failure is quite common. according to my local garage that did the fault code check for me.

It happened to me, flashing glow plug light etc. Found switch had overheated and melted internally.

[Guest SA Intruder]

Relay K198 can cause similar problems, but light is more intermittant.

 

Relay supplies power to ECU. In time, it develops poor contacts and thus intermittant supply to the ECU.

[ALARM MAN]

Also problems if you have cruise control

Same thing with the switch

we have a 98 tdi i replaced switch 8 months ago and guess what

the old switch had a date on it 2000 so i guess this is its third

 

Ian

[Karapaul]

Hi guys

 

My gal has developed the same fault ..... about 20 sec after ignition on - the pre-heat dash light starts flashing regularly - approx every second.

 

I have been overseas for a few months and left the Gal parked up outdoors - when I got back this week the battery was dead. Charged it for a few hours and tried it but it was not enough and the dash buzzed & clicked when I tried to start the engine.

Then I fully charged the battery and it started fine - but after about 20 secs the flashing light started.

 

I have checked the brake lights ..... all 3 working perfectly.

 

I have (provisionally) checked the brake light switch which seems to be working perfectly, so according to the previous comments - I guess tomorrow I should check relay K198 (wherever that is!).

 

Everything else seems to be running fine - so I don't think it is a big problem - just bloody irritating (especially when driving at night).

 

If anyone has any more suggestions - please speak up.

 

Thanks in advance :D

[andymet]

Hi

I had the same problem with the flashing light, I checked the brake light switch with a mutimeter (Its the black one at the top not the blue one that dumbo here checked to start with!) and it seemed ok but was obviously failing when current was passing through it as changing the switch for a new one cured the problem. For the sake of

[Masked Marauder]

The switch is actually two switches in one. There is a little pin inside that when the pedal is not pressed holds the contacts open on the brake light switch and the other contacts (for the ECU switch) are closed.

 

When you press the pedal the pin moves off the brake light part of the switch allowing it to close and moves onto the ECU side opening it.

 

So when the system checks it looks for one switch open, the other closed. If it finds both open or both closed it flags it up as an "implausible signal" on the ECU module.

 

So thus, it is possible for the brake lights to still work and the switch to be faulty.

[Karapaul]

Excellent responses guys ..... thanks, I appreciate it.

 

As you both infere ..... for 8 quid I might as well change the brake light switch.

 

 

By the way ...... I have also noticed that I get the 5 long beeps when I turn on the ignition. The Gal starts fine and runs fine but I know the battery is not 100% since I left it for dead all those months ago, so I'm guessing that a better charge (or a new battery) will cure the beeps.

 

Cheers again

Paul