Firstly may I apologise for posting another thread about Engine Failsafe Mode, but, having read the other posts, I would like to get feedback on my specific problem.

I have a 99 S-type 3.0L V6 Manual with only 70K on the clock. Recently I started to get the amber EFM warning coming on intermittently. However a couple of days ago I was driving back to Scotland (in a Blizzard!!!) when the EFM went to red and into limp mode. I restarted and the same happened again.

After a couple more attempts I started up and floored the accelerator pedal and managed to get up to 35-40 where I was able to engage the cruise control and then control the speed using the Steering wheel speed buttons. I did this as i had noticed that the EFM warning did not come on when in cruise control and I managed to get the car home, although the EFM still came on as soon as I used the accelerator pedal again.

Having read most of the other posts regarding EFM issues it would appear that there are a few main suspects: Brake Switch : Dirty Throttle Body : Throttle Body Connections : Accelerator Pedal Sensor.

Given that the car operates without issue on cruise control and using steering wheel speed adjustment, I am guessing the problem is with the Pedal Sensor.

I am a practical person and a tradesman by profession but I am not an experienced mechanic.

I would appreciate any advice on whether I am on the right path to resolving this problem and (assuming the sensor is the problem) advice on how to clean/repair/replace the offending unit.

Thanking all forum members in advance for any help the can give.

brianht

P.S. I 'think' the traction control button may be stuck in the on position at present but whether that has a bearing on the EFM problem I couldn't say.

 

Does the UK use OBDII scanners to read and interpret the various trouble codes thrown by the ECU as a result of problems such as yours? If so, I would start by reading the codes to find out what has been thrown thus far....

I agree from your description that I would suspect the accelerator pedal sensor first, but I would read the codes prior to spending any money on potential fixes....

 

Frankly it's far more likely to be misfires and/or vacuum (air) leak, especially as you have the very engine which has these as common faults.

Read about those, especially coils, water in engine bay, PCV elbow etc.

On cruise there's only light engine load unlike accelerating.

If you have an air leak or misfires you are at serious risk of cat damage. Try not to drive the car until diagnosed properly / mended.

Best place to start is reading DTCs (codes) using OBD. Plenty of threads about that here and on UK forum.

Hi Jon - yes UK does. Strictly it's EOBD (European OBD) but essentially the same.

 

Thanks for the advice so far, I will try to find a mobile auto electrician who can read the codes for me.

I did take a look under the bonnet today and noticed that the unit mounted to the front of the throttle body, which I am guessing (from pictures I have seen of parts available) is the Throttle Position Sensor, was loose at the upper mounting and had a couple of mm's of movement.

Could this be the source of my problem???

 

Oh heck yea! Do a search of Limp Mode. The Throttle Position Sensor has been the subject of quite a few threads.

 

Why guess? Read the DTCs.

 

Just an update on the problem I was having with EFM.

Tightened the Throttle Position Sensor upper screw(and the lower just in case!) and have been driving the car (very gently at first) regularly for nearly 3 weeks and have had no warning lights at all.

I think that, once again, the attrocious state of Edinburgh's roads, including its many cobbled streets, has taken its toll on my transportation. Previously I had a Saab 900 and Edinburgh's roads managed to break both front suspension springs.... sigh!

Thanks for the feedback and is there any point in getting DTC's read now I have no warning lights?

 

Are you a gambler? If you love to take risks, hope for the best. It's just a car, right?

 

Brian

How's the S type now? I've got the same problem in Newcastle. Did the work on the throttle work. I've had the body replaced on mine last Friday, which has settled the revs a bit, but they're still causing the FSM amber to flash on.

thanks

Craig

 

Hi Craig,

After tightening the Throttle Position Sensor I had about 4weeks of no warnings. Then on a very rainy day I drove from Dundee to Edinburgh and at the end of the trip the EFM warning re-surfaced. I took the car to get the OBDII codes read and the technician flagged up 1 code: P1577 Pedal Position Sensor Disagreement btwn Sensors.

He cleared the codes and suggested that I might think about cleaning the connections. However since he cleared the codes I have had no more warnings and am reluctant to do anything at present.

I think that all the snow (much of which I dragged into the footwell with my big workies boots) has created a little to much damp in that area and some of the water has evaporated then condensed on the PPS.

I have read that giving the PPS a good soaking in WD40 can remedy the problem but, as I said, It aint broke so.......

Hope this helps

 

Hey Brian

yep the weather's been pretty poor down here. I had the throttle box replaced and the consensus is the throttle sensor not talking to the clutch. The revs would rocket whenever the clutch went down. I had it in the garage last Thursday where the mechanic remapped everything and I dont wish to tempt fate but it seems fine so far.

thanks for the response.

Craig

 

Consensus? Who came out with that?

 

well the mechanic said that the probable reason the rev counter rocketed when the clutch went down was to do with the throttle box and or the throttle sensor.

Craig

 

I'd change mechanics as that's soooo unconvincing. I hope it was cheap.

 

oh yeah 80 quid. The problem seems to have settled down. But its only been a week...