Hi Guys,

A few weeks ago (didn't think anything of it) go to start the car one morning - battery was drained. It cranked a bit (about 5 seconds then click, click, click) the battery needed a boost.

Put the portable battery jumper on and got the car started - all was good but the engine light was on and I pulled P1587 (TB - Modulator Command Malfunction) - car was driving fine after the jump start - no "limp mode".

Cleared the code the next day - no issues since until...

We had a very bad rain storm on Friday - like 2" of rain within 90 minutes. I wasn't using the car this day - it was parked on a level surface. Go to start the car yesterday - same deal - battery drained - cranked a bit then click, click, click...

Jumped the battery and same deal P1587 (no drive-ability issues and no "limp mode") - drove the car 87 miles today alone (city/highway) - no issues - just the engine light.

Battery is about 2 years old..

My questions are:

1) Could water have gotten past the cowl and into the TB - causing this issue? I didn't apply the cowl water intrusion fix - never had an issue before.

2) Would trying to start the car with a drained battery cause this code? Tested battery yesterday it was at 11.67 V after trying to start the car.

3) Since OBDII flagged the code - if the code is rectified (loose connection/temporary issue due to low battery voltage/wet connection) will the check engine light go away if this fault is not present after XX successful drive cycles?

4) I believe I have found the culprit for the battery drain (ignition flap switch)

In the meantime - going to check all electrical connections at the TB and TPS to ensure good connections.

Thanks for any feedback - Anthony

 

If the flap was causing a drain the code may in effect be false. The MIL would go off after a few (I think 3, some say 5) warm ups and the fault being gone. The code stays stored for many (40 or 80) warm ups then is auto-erased.

 

I am in to similar situation, car was parked for three months, returned to it and trie startung it out the battery was dead, jump started it, drove it for 5 miles, during this time the car was making excessive noise, at first I thought it was due to the rust on the rotors, but not, after driving it for more than 5 miles, it is still making that noise, the rust is gone but the noise hasn't, also, the ABS and DSC lights have came ON ! Along with check engine light - P1587 !

Could anyone help, please? Is it safe to drive in this condition? Is it possible that brake pads have worn out ( surprising cuz I just changed them few months ago before parking the car for 3 months) ?

 

You need to find the source of the noise(s), whether you enlist friends or take to a shop.

The code may be false but equally may be as per the workshop manual - free download.

 

The noise? No idea if it is safe like that, probably not. Does it continue when the car is stopped at a light? If so, the noise is drivetrain related. Or does it only happen with the car in motion? That's probably something with the wheel bearings or brakes. In that case, jack up each corner one at a time and spin the wheel. See if the noise is present.


The fault codes and warning messages? Most likely your battery is toast from sitting so long and running down. These cars are very sensitive to the prestart battery voltage. If you have to jump the battery, expect problems. Put the battery on a charger overnight and see if it behaves now. Take the battery to a parts store and have it tested if you have any doubts. Lots more info about how these cars react to low prestart voltage here:

https://www.jaguarforums.com/forum/s...attery-193787/

 

If it helps no noises when I had P1587 code.

 

Hi ivicks,

It always help others give you the most accurate responses if you provide the year, model and engine of your Jaguar.

Low battery voltage can cause all manner of spurious Diagnostic Trouble Codes to be triggered, so it's possible that if you resolve your battery issues and clear the DTC it may not recur. For reference, here are the definition and listed possible causes of P1587 from the 2001 DTC Summaries:



PCM is the Powertrain Control Module/Engine Control Module, and TACM is the Throttle Actuator Control Module. If the code persists, it would be worth cleaning the electrical connectors at the throttle body and PCM/ECM and the ground points referenced by the Engine Management System (EMS).

Regarding the noise, if it only occurs while moving, it is possible the rust from the rotors has been scrubbed into ridges or piles just ahead of the brake pads and continues to make noise even when the brakes are released.

It is also possible if not likely that the ABS/DSC warning lamp is due to rust from a rotor having attached to an ABS wheel speed sensor due to magnetic attraction, causing the sensor signal to become implausible. If you have access to a scan tool that can read the proprietary Jaguar B- (Body), C- (Chassis) and U- (Network) DTCs, you will probably find that at least one C-prefix DTC has been triggered, which may identify the corner at which the problem exists.

Please keep us informed.

Cheers,

Don

 

Excellent point, Don. I forget my truck behaves like this sometimes, as I don't drive it too much. When this happens, I've found backing up on a deserted street and applying the brakes quickly a couple of times usually takes care of the noise.