Hi, I've owned my 2001 S-type about ten years now and apart from a major gearbox change its been running fine. After a house move I took the car to a local garage to have the air-con topped up. Went to pick the car up but it had gone into Fail safe. The garage tried a throttle pedal change but no good so gave up with them. I got the car home and started to read up on possible solutions. Most seemed to point to a throttle body problem/throttle position problem. Codes P1573,P1576,C257F,P0765,P0100. I have changed the throttle body but still exactly the same fault, also cleaned the Mass Air flow sensor. If the battery has been disconnect for a while and the car is started it runs fine and revs fine for about two or three minutes and then goes back into fail safe. Battery is good only two years old. Spoke to a jag expert friend of a friend he thinks it could be the wiring along the front bumper causing the problem, CAN problems with the wiring causing bad connections due to corrosion (common fault apparently). I'm ex BT engineer and ok with wiring. I would be grateful for any pointers please as I love the car and would love to get her purring again. Mileage is 67,000. Thanks in advance

 

i don't think 01 had can bus .
p1573 is TP sensor. and p1576 APP sensor (pedal) . id say there is a problem between the two . maybe the mechanics washed your engine . check inside the TPS plug for water .

c257f is not covered in JTIS and neither is p0100 specifically for 2001 any way
. but generically c257f can be cam timing related and also vapor canister related , so maybe just worry about the first two at the mo .
p0765 is a trans fault - shift solenoid 4 malfunction. will just have a harsh shift

there is also a possibility that your battery has run low and caused some of the codes , so start by charging your battery , clear codes hard reboot the car and see what codes come back . i think your TPS is your issue .

 

No CAN on the car unless it's a pre-production oddity (very unlikely) but battery is a very likely suspect.

The loom problems mentioned did not afflict the early cars I believe.

 

Thanks Datsports and JagV8...Datsports when I changed the throttle body it came with a TPS so that's been changed as well. JagV8 is it worth changing the battery?....just for info the car has been like this now for over a year...I've been trying various things during that time. I noticed that one of the connector pins on the TPS connector was bent so I straightened it so its ok now but to make sure I tested the wiring for continuity on each pin all ok. Thanks again you guys for you suggestions.

 

It's hard to test them adequately and one of the cheaper items to change.

Depends how you value your time possibly chasing your tail compared to a battery / how annoyed you'll be if it does not improve things.

Your alternatives look painful, such as "hoping" you've a chafed cable for the items flagged and finding where - study electrical guide very very carefully as it shows far more than most notice.

 

Thanks JagV8....will do... hmmmm food for thought!

 

And should you opt to change the battery there's no guarantee the new one will be fully charged. So be sure to bring it to full charge before troubleshooting as marginal batteries can cause false-positive codes. The last new battery I bought took a full overnight trickle charge to bring it up to full voltage.

 

Thanks Jumpin Jag Flash....good advice...will do

 

The alternator can be changed from under the car just be sure to disconnect the battery before doing anything.

 

Thanks Gus....are you saying I should change the alternator as well as the battery?

 

Ok...new battery fitted but still the same problem..store replaced it free of charge...result!
Started the car and it ran fine and revved all okay for about three to four minutes and then the dreaded "Engine Failsafe" appeared again and then can't rev at all, throttle pedal no response....connected my D900 code reader and these are the codes it found.
P0100 Mass or Volume Air Flo "A" cct
P0765 Shift Solenoid "D"
C257F undefined
P1573 Throttle position not available
P1576 undefined code

any thoughts chaps?

 

Did you clear them first?

 

Hi JagV8....Well...I cleared them with my D900 Its an EOBD/OBII Live data Version 2014...it has an "Erase codes" option and i ran that. Even when i have run erase codes the engine failsafe doesn't disappear. I was speaking to Autel support who make the code reader he suggested that if after the aircon was topped up the garage may have disturbed an earth connection by the bulkhead....do you think this an option?

 

I have no idea why i put this on your thread. I guess I was thinking a charging problem. Sorry!

 

Hi Gus ....no problem mate! I'm just grateful for any suggestions at the moment

 

Use this for your P codes

Link http://jagrepair.com/images/AutoRepa...os/PE20001.PDF

Where did you get the throttle body from? As for the OBDII C257F I am still looking for a definition.

It seems odd that you are getting the same codes after changing the TB. I will provide a link for the wiring diagram for your car if you do not have one.

Link http://jagrepair.com/images/AutoRepa...x2022001en.pdf

 

Hi Gus....I got the throttle body on ebay...yeah I know I'm a cheapskate!....but the problem is exactly the same fault....or is that me being naive. Thanks for the P codes and the wiring diagrams they will come in handy. I've also ordered a newer/later code reader from Autel....my old one is a bit flakey. it keeps showing CRC EEPROM error.

 

If you have a smart phone you can upload Torque on it and then get a Bluetooth OBDII reader and you will be in business. You can find them on EBay for under $20.

Please let us know what you find. Do not overlook the ECM it could be part of the problem.