When I hit the brakes my brake light goes on and the VCM states PAD. Checked the pads all good. Rear brake bad sensor was cut in half replaced it and still light comes on. Also occasionally the ABS light will come on when the brakes are depressed but not always. I noticed that the car only has 1 front and 1 rear brake pad sensor is this correct?

Also I when I got into my car this morning and started her up the transmission light was on, so I drove to work, when i stopped to get coffee I got back in and started it up and the light was gone and it was no longer in limp mode. Briefly looked into it at work not to much success. However when I started it when I went to leave it jerked hard into reverse and the light came on again. I turned the car off and restarted it and the light did not come back on and all was fine. Any ideas?

Lastly anyone have a part number for a replacment bulb for the clock. I am going to pull the hvac to fix it and need to replace those bulbs. It would be easier if I had them beforehand.

Thanks

 

hey cougarman,yes the brakes only have one pad sensor front,and one rear.

If the sensors are breached it may be time for new pads,and sensors.
You can try snipping the sensor wires and join them together to make the light/vcm message go away.

As for the trans. issue,research the threads on cleaning/adjusting the throttle position sensor.It tells the computer what gear you should be in,fueling for the engine,etc. in relation to road speed.

Lots of help here in that regard.
Also,if you get a limp home condition,pull over,shut off car,wait a sec,restart
and see if it will reset,limpy may go away temporarily.

As for the clock,mine is LCD,so not sure on the bulb issue,maybe someone else will know more...


Good luck!
Jim

 

Hi cougarman,

Jim is right on the money regarding the Throttle Position Sensor. On our '93, the most common cause of Limp Home Mode has been oil contamination of the electrical connector for the TPS, which clips to a bracket on the intake manifold a little to the left of the throttle body. I can never remember if you have to press on a plastic tab or gently pry it out to release the connector from the bracket, but you'll figure it out. Separate the two halves of the connector and flush them out with zero-residue electrical contact cleaner spray. Apply a little dielectric grease around the outside of the male part of the plastic connector to help seal out futuer contamination.

Another common problem is contamination of the TPS itself. It's mounted directly below the Throttle Body (TB), and oil in the vapors drawn from the crankcase breather system drip down the butterfly valve shaft into the TPS. Many of us have drilled drain holes in the TPS case to allow flushing it with contact cleaner and giving future contaminants a path to drain instead of accumulating. You don't need to disconnect the TPS from the TB, but you do need to remove the TB from the intake manifold. See the photos at the link below:

Welcome to Jag-lovers - Members Photo Viewing Page


The PAD warning on the dash usually means that a brake pad wear sensor has worn to the point that its internal wire is exposed and is being grounded against the rotor when you apply the brakes. Since you replaced the rear sensor, perhaps there is a problem with the front one?

The illumination of the ABS warning lamp usually indicates low pressure in the hydraulic anti-lock brake system. The most common cause is that the accumulator sphere has lost its ability to hold sufficient pressure. Here's the test procedure from the XJ40 eBook at Jag-Lovers:

Check Accumulator :
Run car at 2000+ RPM for 30 seconds. Shut motor off and turn key on to activate VCM. Pump pedal slowly, 3 count intervals, check the number of times before the low brake pressure warning light comes on. A fully charged accumulator will go 9 pumps. 4 pumps necessitates system check out, probable accumulator bladder failure.


If your accumulator tests OK, the other components in the system that can fail are the electric pump (not common) or the pressure switch (it failed on our '93). My money is on the accumulator if yours is older than 5 years or so.

Regarding the clock bulbs, they are specialized type with a plastic base that mounts directly to the circuit board. I'm not sure Jaguar even offers replacements anymore. The replacement bulbs for the instrument cluster were $12 to $15 each from Jaguar the last time I checked, so I and other owners have come up with other solutions:

1. Purchase a salvaged clock panel with working bulbs or radio/climate trim piece that includes the clock with working bulbs.

2. Replace the "grain-o'-wheat" style bulbs in the original plastic bases with new bulbs. Here are a couple of my posts at Jag-Lovers about the bulbs I found and how to remove the old bulbs and install the new ones:

JagFORUM Logon
JagFORUM Logon

The photos at this link show the instrument cluster bulbs. The clock bulbs are similar, but if I recall correctly, the plastic bases have flat backs with a screwdriver slot but no hex extension for a socket:

Welcome to Jag-lovers - Members Photo Viewing Page

3. Option 3 is probably the best, and that is to reuse your plastic bases, but replace the grain-of-wheat bulbs with LEDs. Here's a post from Mike Stone at Jag-Lovers and a link to photos showing his results:

JagFORUM Logon
Welcome to Jag-lovers - Members Photo Viewing Page

Cheers,

Don

 

Thanks for the replies will check this out as soon as it stops raining.