Hi guys, as i went for an mot re test for the emmisions my abs light came on so they failed the car on even worse emmisions (even having replaced the lambda) and the ABS not working.
The pump, of which i can find no mention of on any mx5 forum is making a noise even when the ignition is switched off!!!
I am going to disconnect the battery to stop it draining overnight. I cant find any diagrams of the relays or fuses to help me isolate it.
Has anyone else had this problem?
Also the ABS diagnostic tip sheet is of no help as i dont have all the connectors that it talks about…
Its a 93 MX5 se with abs, no power steering. UK limited edtion.
Love the car and it sounds great with new stainless exhaust from mx5parts but between emmissions and abs im pulling my hair out. Moving home this weekend too!!!
Booked in with mobile mechanic on tuesday morning but sure i can fix both problems myself with your help…
Cheers
Ben
Driven through any floods or snow recently?
No, just regular fast driving! I avoid driving into lakes but cant wait to wag the tail in the snow. Thats if i can get the ABS working to pass the MOT!!!
I have removed the relay switch and this stopps the pump wiring noise but the abs light still on. Can i disconnect the abs altgether and run sans assistance?
I don’t believe you can pass an MoT simply by disconnecting ABS. If you were to strip out the whole system and fit standard brakes, maybe.
Only the warning lamp is tested on the MOT but if it’s missing then it’s a fail. I think it will depend on the tester as to whether he passes it with the ABS system removed. Have a look at the wording in the inspection manual (see Garage General for a link).
The ABS system on early NAs is a stand alone system and is not diagnosed through the diagnostic connector. There is a (rare, I’ve only seen one once is 15 years) tester to test for faults and a workshop manual dedicated soley to that type of ABS system. Get in contact with me if you have no joy with your electrician. I seem to recall seeing a car with a similar fault a few years ago, the repair was going to be a new pump at stupid money but it just one day fixed itself. I think it may have been a sticking pump motor relay.
Text below taken from the MOT inspection manual.
Information
This inspection applies to:
· All systems fitted as ‘standard’,
and
· ‘optional’ systems fitted.
When testing vehicles that have ABS fitted the road wheels should not be allowed to rotate clear of the standing surface with the ignition on as this can cause the ABS system to indicate a fault which may require specialist equipment to rectify
Missing components Where a vehicle is presented for test with an ABS component obviously missing but, follows the correct sequence of operation, the defect must be brought to the attention of the presenter.
Method of Inspection
1. If the vehicle is fitted with an anti- lock braking system, check that
a. a warning lamp is fitted
b. the lamp illuminates
c. the lamp follows the correct sequence of operation
d. does not indicate a fault.
Note: The sequence varies with the type of system. Refer to VSI, manufacturer’s or other reliable data, e.g. purpose produced charts, books, etc.
Reason for Rejection
1. The warning lamp
a. is missing
b. does not illuminate
c. does not follow the correct sequence of operation
d. indicates an ABS fault.
I suppose you could get away with removing it under Method of Inspection 1. “IF the vehicle is fitted with an anti-lock braking system”
Amazingly i just disconnected the system for a few hours and the fault has disappeared. No noise, no light on the dash and no locking wheels when i brake hard!
Guess i just got lucky…