I have the manual, it talks about sensor gap, but not what the gap is for front and rear or how to make adjustments. Does any one know what the gaps are for 1996 355 front and rear and how to make adjustments.
It's 1mm plus or minus half a mm...so a big tolerance. I think it's abit too big a tolerance, so I try to keep them at 1mm +- 0.2. Measuring them accurately is the hard part though. You need shims to space them out. Make your own from shim sheets from a bearing wholesaler. Tricky though.
How do you get at the ABS sensor unit to make the mesurment? I pulled the bolt and cover off the back side and It does not expose any thing. Do I need to pull off the disk brake hub to get at the location and at what point do I make the mesurment.
you need to remove the sensor and measure its' length. Then you measure from the hub surface down to the sensor wheel tooth top, and subtract the sensor length from it to find your gap.
It's supposed to. It can be a bit snug though....in bad cases the hub corrodes and/or the sensor get's jammed for other reasons. You may have to drill the sensor out and replace it, but that's worst case. Before you have a nightmare...have you put a fuse in the abs diagnostic slot and observed the faults code??
Yes, after sprending $2,700.00 at the Ferrari dealer, they changed the complete ABS wireing harness, I still have code 5.8 and 7.4 and they told me the sensors are ok and they think I need a new master cylinder valve body at a price of $6,500.00. they changed the ECU with a 355 that they had in for service and the codes stayed the same. I put the fuse in and come up with the same 5.8 and 7.4 that they did. I found someone on the maindland that repairs the Tevis units and he said the problem does not look like the master cylender valve body. The dealer also swapped out the ABS pump, no change.
so you know that 5.8 and 7.4 refer to left hand front and L rear sensors then....are you sure the counting is correct because it would mean you have two faults. 5.8 7.5 would both refer to L front sensor. TRIPLE check all chassis earthing points...there's groups of earths bolted to little studs all over the place. I couldn't tell you which to look for. Check all the sensor connnections under the wheel arches and front panel etc. Measure the resistance through the sensor via it's connector plug....about 700-1200ohms is ball park ok.
I will check the resistance tomorrow, I don't have a breakout box but I did figure what the pinout are at the connector at the ECU. The codes are correct, two probems exist. I have checked the numbers several times and they match the same number that the dealer came up with. Thanks Phil, I will let you know what I find.
Code 7.4 is clear. Cleaned the sensor and checked the gap. Still have code 5.8. Cleaned the sensor the gap is larger than it should be. I removed the spacers, but the gap is still to much. Any ideas how to fix the problem????
Make sure the wheel bearing is good, and that the sensor wheel is securely mounted. Try swapping sensors from side to side to see if the fault follows the sensor or stays with the wheel.
Hi Phill, I removed the whole front hub assembly,cleaned the sensor and the gear, it's is gaped properly now, wheel bearing is ok and gear is bolted tight. Retested the system twice by taking the car on the road and checking the codes twice, 5.8 is still showing and 7.4 came back. I found the ground for the ABS brake harness to be tight.
like I said...swap the problematic (according to codes) sensors around...put the LF in the RF and LR in the RR, then see if the code changes. To fix this you're going to need to do a lot of swapping to rule things out. Try to get an extract from a workshop manual for abs diagnosis, there's loads to go through. Loads of test to perform etc etc..... By the way, I'm assuming you've got a teves system and not a bosch.....
Sounds like the dealer technicians need a trip to New Jersey for Diagnostic Procedure 101. FNA has great technical depth and experience, sometimes a dealer may not utilize that resource. I would not hessitate to ask, "What did FNA say?"
I had a 335 ABS problem and Malcolm at F-UK helped me perform all tests without specialist equipment..... Just workshop manual info and a multimeter and some crafty contact bridging at the ECU and you can test anything. I found an ECU that showed a rear return valve to be faulty, even though the valve tested ok....it's an ECU code clearing error, not a component error.
How do use a fuse to read codes? After my last service the brake and ABs lights came on and I may have to perform this troubleshooting myself as I have blown my 355 maintenance budget for the year -Michael
1 a 5 or 10 amp fuse into the holder. 2 Turn Key On 3 Count how times the light blinks untill they stop for a few moments.(that will be the ten digit) 4 Count How many times the light blinks untill it stop again (that will be the unit digit 5 Then have someone remove the fuse momentarly and replace it. 6 If it starts the blinkig cycle again, that will indicate a second trouble contition. 7 Repeat this pattern till all the code are read. 8 The codes are should clear when the car reaches 40 MPH if the probles are corrected. (So I have been told)
Thanks for the reply 355Aloha, but I'm still a little confused....which fuse holder are you referring to and where is this light that blinks? Thanks! Michael
The abs warring light on the dash is the light that blinks. You have to remove the carpet from the trunk by the firewall on the passenger side to expose the fuse holder on the side of the ECU (it will be the emty fuse holder, thats where you plug the fuse in to test) Don't forget to remove when testing is done.
Are the codes detailed in the workshop manual? How are you relating the codes back to what is wrong? -Michael
