[Sutripta]

Originally Posted by mayankjha1806

Whats a Fuel temp (temperature?) sensor, or did you mean just the normal temperature sensor?

Originally Posted by rocky080

I was talking about the Fuel temperature sensor and not the cooling system temperature. I guess turbo diesels have this sensor.

Used for density calculations.

Regards
Sutripta

[mayankk]

Also, could this be some problem because of removing Pete's box?

[rocky080]

Originally Posted by mayankk

Also, could this be some problem because of removing Pete's box?

Nope, i have removed the petes box and run it in stock form lots of times previously. This issue has only started from the last 5 months and i have also checked all the injector coupling for roper fitment.

Regards,
Rocky

[rocky080]

Hi guys, update regarding the issue i was facing, its finally fixed .

The issue was with the front cross member and suspension aggregates which had a couple of loose bolts because of which there was a small deviation in the wheel speed sensor reading due to play being caused.This inturn was causing the Traction control system(TCS) to limit the rpm to 2700 rpm. It was fixed by removing the entire front cross member and suspension aggregates on both front wheels and refitting them and tightening all the bolts. I have driven the car about 500 kms after the fix and everything seems to be working fine.

Thanks for all the suggestions and help.

Regards,
Rocky

[SS-Traveller]

Originally Posted by rocky080

...a small deviation in the wheel speed sensor reading due to play being caused.This inturn was causing the Traction control system(TCS) to limit the rpm to 2700 rpm.

Didn't know that the Elantra comes with TCS. And there was no error code being recorded by the ECU because of this?

[d_himan]

Originally Posted by rocky080

Hi guys, update regarding the issue i was facing, its finally fixed .

The issue was with the front cross member and suspension aggregates which had a couple of loose bolts because of which there was a small deviation in the wheel speed sensor reading due to play being caused.This inturn was causing the Traction control system(TCS) to limit the rpm to 2700 rpm. It was fixed by removing the entire front cross member and suspension aggregates on both front wheels and refitting them and tightening all the bolts. I have driven the car about 500 kms after the fix and everything seems to be working fine.

Thanks for all the suggestions and help.

Regards,
Rocky

Thanks for the update! Reads like a mystery novel - so another thing to watch out for if a car is equipped with TCS!

[rocky080]

Originally Posted by SS-Traveller

Didn't know that the Elantra comes with TCS. And there was no error code being recorded by the ECU because of this?

I guess there was a version of Elantra which had all these features stripped aswell (not sure though), but mine is the top end 2006 model which has all these features. There was no error code being generated because the TCS system was just interpreting the wrong reading from the wheel speed sensor as loss of traction in the wheel and limiting the rpm just as it is supposed to do when the car actually loses traction during adverse driving conditions.

Regards,
Rocky

[anandpadhye]

Originally Posted by rocky080

There was no error code being generated because the TCS system was just interpreting the wrong reading from the wheel speed sensor as loss of traction in the wheel and limiting the rpm just as it is supposed to do when the car actually loses traction during adverse driving conditions.

Regards,
Rocky

But then the TCS light should switch ON. In my Laura, when I get into front wheel spin, the ASR light switches ON momentatily till the car regains the grip. In your case, due to incorrect readings from sensors, the perceived wheel spin/loss of traction was persisting over a much longer duration, am I correct? A warning lamp (yellow/amber) must flash. If no lamp flashed, you should check the wiring around it to see if all warning lamps are working fine or not.

Please keep us posted, this was a good piece of diagnosis.

Cheers!

[rocky080]

Originally Posted by anandpadhye

But then the TCS light should switch ON. In my Laura, when I get into front wheel spin, the ASR light switches ON momentatily till the car regains the grip. In your case, due to incorrect readings from sensors, the perceived wheel spin/loss of traction was persisting over a much longer duration, am I correct? A warning lamp (yellow/amber) must flash. If no lamp flashed, you should check the wiring around it to see if all warning lamps are working fine or not.

Please keep us posted, this was a good piece of diagnosis.

Cheers!

I am not to sure how the TCS works in the Laura but on the Elantra the yellow TCS light turns on only when there is actual wheel spin with TCS on.

What was happening here is that the TCS system was getting incorrect reading from the wheel speed sensor and was trying to stop the wheel spin before it actually occurs, under this circumstance the light does not come on.

Below is an extract from wikipedia regarding all the system the TCS affects:

"intervention consists of one or more of the following:
Reduces or suppress spark sequence to one or more cylinders
Reduce fuel supply to one or more cylinders
Brake force applied at one or more wheels
Close the throttle, if the vehicle is fitted with drive by wire throttle
In turbo-charged vehicles, a boost control solenoid can be actuated to reduce boost and therefore engine power."

Full Link: http://en.wikipedia.org/wiki/Traction_control_system

I guess this is why my engine rpm was getting limited to 2700 and no more. Also, all the wiring with TCS are working perfectly fine as when i do a sprint from dead stop in slippery condition(Rain or gravel) the yellow TCS light turns on.

Regards,
Rocky

[LP640]

Hello all!
The mystery book opens a new chapter!

Mine is a 2005 petrol Elantra. Today on the way from Mumbai to Pune my fuel hit the red mark(Distance to empty shows 75 km). I cross first toll and refuel for 1000 Rs(I wanted to tank up later at Shell)

Started climbing ghat and suddenly after 10-12 km, no power is delivered by the engine. I drove a few km in 1st and 2nd gears. Found a place safe for parking. Stopped the car and started inspection. Engine was a bit hotter than usual. Temp gauge was showing perfectly ok temperature. Started car but it idled at 400 rpm (normally 900rpm). Started driving and still no power. I could not rev it beyond 3000rpm. Exhaust note changed to the ones like today's half dead Opel Astras.

Got off at Lonavala. Found a mechanic. We opened the hood and saw the exhaust below cat-con was red hot! Engine temperature gauge showed a modest half way temperature. He removed the coolant temp switch and pointed that the cooling fans did not start. He said the fans should run default after disconnecting the switch. He tried connecting-disconnecting 2-3 times. I tried turning on AC to turn on condencer fan, but in vain. We checked all fuses and relays. All ok. Suddenly both fans come to life.
Both fans were now running, after disconnecting the coolant temperature switch.

Drove to Pune with both fans running, and with nearly only half power from engine. Exhaust note continuously sounded strained and leaky. Stopped 2-3 times on the way to let the red hot exhaust cool down. Car did decent speed (100kmph). I maintained high speed to help cooling down engine/exhaust. Power drop was such that when I put my foot down at 100kmph on 5th gear, there was absolutely no response!

I believe I do not have a problem with TCS as my problem starts right at idling. Car takes more than normal time to startup. Also startup sounds like the one we get when the battery is down. My battery is new so actually the engine is strained. On idling, I have to floor the throttle, then the rpm rises after 4-5 seconds to 2-3k.

Can anyone help?

[bdubya]

Rocky - Can you please let me know which service station you go to in Bangalore and who was the SA who diagnosed the issue . Im trying to find a knowledgeable person for the Elantra CRDI

[jhaji]

Friends,

Three year warranty on my car expires in three days on 27th. A correct diagnosis would be really helpful.

I started on a driving trip to the mountains with a friend on Saturday. About 70-80 kms from Delhi, on the Hapur by-pass, when the car was traveling at around 70-80 kmph in fifth gear, I suddenly experienced a power loss as if the accelerator became ineffective, though the engine didn't stop. I looked and saw that a warning sign, which means engine malfunction, has appeared on the dash. I stopped on the side. When started again, the car seemed normal in 1st and 2nd gear, but the warning sign stayed.

Called Toyota road side assistance and they advised not to drive on. They sent a tow-truck which arrived in an hour and the car was taken to the Uttam Toyota workshop at sector 63 Noida.

When I reached the workshop, the service advisor told me that when they started the car upon arrival, there was no warning sign any longer and everything seemed normal.

Next day, in the diagnostics test they could only find one minor fault where one cable connection to the battery was loose. They did a long test drive and they ran a series of tests which is recommended by Toyota which took the entire day yesterday. The advisor informed me that they could not locate any fault and they cannot say why it happened. They were planning to do another long test drive this morning and then give me the car. I do not know exactly what the diagnostics test showed or did not. But they say they can't locate the fault.

I plan to pick up the car in the evening and drive it on the highway for at least 100 or so kilometers to see if the fault re-appears. My warranty is expiring on 27th and I am keen to find a possible reason why this sudden loss of power may have occurred.

Any clues, please?

[Jeroen]

Originally Posted by jhaji

Next day, in the diagnostics test they could only find one minor fault where one cable connection to the battery was loose. They did a long test drive and they ran a series of tests which is recommended by Toyota which took the entire day yesterday. The advisor informed me that they could not locate any fault and they cannot say why it happened. They were planning to do another long test drive this morning and then give me the car. I do not know exactly what the diagnostics test showed or did not. But they say they can't locate the fault.

Do you remember exactly what light or message appeared on the Dashboard.It was likely to be some sort of limp home mode as the engine was still running.

As it appears that it disappeared by itself it was likely to be a relatively small issue that made this happen. There could be a whole vast range of different issues that can cause it. On the upside, usually when it something really material it would store the code and it appears as if they couldn't find any stored fault codes.

I would not rule out the cable connection either. Modern car electronic will only work well when they get provided with a good power supply and grounding. One bad connection can give all sort of pecular behaviour, which often is very difficult to trouble shoot.

A single bad wire can cause cars to go into "limp home mode" or reduced performed mode or whatever it gets called. Once, my Jaguar went into "limp home mode" due to one faulty micro brake switch.

The botton line is that I think it will be impossible to say with any degree of certainty what happened. It could have been the cable, it could have been something else, most likely minor. It's unlikely to be anything major as the fault code would have been stored. But unfortunately, no guarantees.

This is one you just have to hope for the best it just doesnt happen again. But if it does, disconnect the battery for a minute, reconnect and see if everything returns back to normal. This will (to a largre extend) reset the ECU and hopefully get you home. If it is a real serious problem, resetting the ECU isn't going to happen.

Not a very satisfactory answer I would agree, but still, in my opinion, that's where you stand today with your car.

Good luck

Jeroen

[kpzen]

How many kms has your car done ?

1. Check alternator.
2. Get the job card made for record purpose in case the same issue re-surfaces later.

Being a Toyota, I don't think you need worry much.

[Jeroen]

Originally Posted by kpzen

How many kms has your car done ?

1. Check alternator.
2. Get the job card made for record purpose in case the same issue re-surfaces later.

Being a Toyota, I don't think you need worry much.

I can think, on top of my head, without referring to manuals, at least fifty different reasons or components in a car that could cause this problem. Based on what analysis or logic would you like to check the alternator first and for what would you check it for?

Jeroen