ABS + E-Brake + O/D Light = Please Help!
 

Hi all,

A few weeks ago, the ABS and E-Brake light would come on intermittently but recently it has been coming on much more often. I brought it into the closest dealership to get it looked at and they diagnosed it to be the right rear wheel speed sensor. Since they wanted $440.00 CDN for the part / labour / diagnostic, there was no way I was going to let them do it. I followed the service manual and inspected the resistance of the sensor - and it turned out to be 1.435 kilohm - within the 1.3 - 1.7 kilohm as specified in the manual. I disconnected and reconnected the connector and did a test drive and both ABS and E-Brake lights went off. So I thought it was a loose connection or something ...

Last Friday, I took my car into the original dealership where I bought my car and had a regular oil change. As I was driving home, the O/D light started flashing and I could feel that the car lost a consider amount of power - I could barely make it up my driveway. I turned the car off, restarted it, took a test drive around the neighbourhood and I couldn't reproduce the problem. Fast forward to today, the O/D light started flashing again and the car felt like it was jerking upon shifting gears. Several times, I turned the car off, turned it back on, drove for a short distance and the O/D light started flashing again with the car feeling really sluggish. I also noticed that the ABS and E-Brake light are constantly on now as well.

Unfortunately, I don't have access to an OBDII scanner (we don't have AutoZone or PepBoys here in Canada) so I'm not sure what code it's spitting out ....

So to the gurus out there, based on what I've described, does it sound like I'm dealing with one issue or multiple issues? Would a defective right rear wheel sensor cause something like this (i.e. was the original diagnosis correct)? Depending on the code, are these signs that there's something wrong with the ABS HU/CM unit (as outlined on 05-02-11 in the service manual)? Could the oil change last Friday at the dealership have possibly contributed to the O/D light flashing since that's when it started happening?

Oh and the car in question is a 2002 Protege ES with only 15,000KM on it (very low mileage since the car is driven mostly in the summer within the city).

Any help or feedback would be much appreciated - thanks!