ABS fault, cruise and speedo working

[RoverDan]

Started a few days ago, had a chance to look at it this morning.

ABS light on, speedo works and cruise will engage - although it lurches seemingly with throttle on,off,on,off,... and so is unusable.

Plugged in TOAF and it is alternating between '7 - front left sensor' and '14 - control unit' errors. Can clear either error but it returns ~ 5 seconds after starting, when stationary. Varying estimates of vehicle speed from 2-27km/h are logged with either fault despite being stationary.

Sometimes refuses to talk to ABS ECU despite scanning the rest of the car, closing TOAF and unplugging cable seems to reset that - TOAF fault or ABS ECU fault?

Have checked the NSF sensor wiring visually, all clipped in place, no chafing.

I'm thinking now that I need to check the ABS ECU connector for corrosion under the battery box. Have found this and this which may be useful if corrosion is found. Will have a chance to work on the car this evening.

Any thoughts?

[hinged_bap]

not sure, i bookmarked this link previously which may ( or may not )be useful:


http://www.macfadyen998.plus.com/

[RoverDan]

Update: it was the sensor.

Having removed the battery box and checked underneath, the ABS pump/controller looked unmarked, certainly nothing to suggest external damage.

I did notice that two earth points on the inner wing, normally hidden by the battery box, were looking crusty. Eased the bolts off with lots of WD40 and loosen-tighten-loosen-tighten (exposed threads were very corroded under the arch liner) and then cleaned them up and reassembled with copper grease.



No recurrence of the '14 - control unit' errors seen previously, just a consistent error for NSF sensor. I presume one of those earth points I cleaned was significant!

The NSF sensor fault came on in the self-test phase after the engine had been running for ~5 seconds, but with no movement, so I concluded it was unlikely to be the 'active bearing'. Copped out and gave it to my friendly mechanic to sort, complete with spare sensor, fearing that it might be a 'hub apart & drill' job, turned out to be a simple replacement - typical! During the first investigation I had loosened the suspect sensor and sprayed it liberally with WD40 whilst working it from side to side, perhaps that had helped.