I've read many posts and gleaned much information on this common issue, but I have yet to figure what's causing it in my car.

Symptoms
- ABS & Brake light indicators go on and off for periods at a time.
- About 15% of the time, when starting from a complete stop, the speedometer will remain at zero and the car will not shift into second unless I rev it to about 3000 and quickly let off the accelerator. Once into second, the speedometer will begin working and everything seems just fine. Also, the speedo often does not start working until about 4mph.
- ABS would occasionally kick in (you could hear it pulsing) when stopping slowly on dry pavement. Although now I do not believe it is working at all as I tried hitting them hard on my slippery garage floor and the fronts lock up and no ABS pulsing occurs.

Steps I've Taken
- Cleaned up the ABS module ground connection (behind the headlight).
- Retrieved the following ABS codes: CO237, CO236, CO267, CO269, CO222, CO265
- Replaced the front right abs wheel speed sensor. The replaced sensor had a little red grease and a very slight film in places. The replaced and new sensors test at 998 ohms.
- Pulled the VSS. Slightly dirty. Cleaned it. It tests at 1520 ohms across the pins so I'm assuming it's good. I have a new VSS but have not installed it since both the new and the old one test at 1520+- ohms so I don't think this is the problem.
- Checked continuity of both wires from VSS connector to PCM. A-OK.

Questions
I read a post about ignition switch issues and this reminded me that about a month ago, the starter solenoid often would just click and not engage the starter. After about 3-5 attempts by turning the key off and on again, the starter would engage. This went on for about a week but hasn't happened since. This all makes me wonder if it could be the ignition switch. Do you think this is the cause?

What is the likelihood that the issue stems from:
VSS
Ignition Switch
Driver side wheel speed sensor
ECBM

Thanks

------------------------------------------------------
Update - Speedometer / Shifting problem resolved
------------------------------------------------------
The car started clunking in the front right wheel. Passenger side CV axle was no good on the inner side. I replaced it along with axle tube seal and needle bearing. This resolved the clunking and the leaking axle tube but not any of the above described symptoms.

I pulled the ignition switch and discovered that one of my contacts was quite burnt. I cleaned them up and was in the process of re-installing when I realized the tumbler was not correctly aligned with the switch. When disconnecting, for a second time, the little electrical connector that you rotate 90 degrees to disconnect, I broke it. I purchased and installed a new switch but this did not correct any issues, although I wonder whether or not this will correct an occasional, slight headlight flicker issue that I've had for a long time.

Yesterday I did the following...
I pulled the connectors to the abs (Kelsey-Hayes) to check the front wheel speed sensor readings. I did this by raising the vehicle so all wheels were off the ground, putting the car in 4wd, then with my meter plugged into the b1 - b2 (c1 - c2 for other side) of the connector, I put the car in drive to check if AC voltage was being generated by the sensors - seemed OK. Then, with the car in park, I check for resistance and both seemed fine.

I then checked resistance on the VSS again and this time there was no reading so off to the parts store I went.

I went to O'reilys and they pulled/erased my abs codes (AZ could not do it). The code was "no signal - front left wheel speed sensor". I didn't buy a new wheel speed sensor since I wanted to inspect the bearing more closely first and try replacing it with one I had at home. I did, however, decide to replace the VSS ($80). I replaced it in the parking lot and my speedometer / shifting problem has been resolved. At first, I really didn't think that the VSS was the cause since it showed resistance the first time I checked it and it didn't seem to make sense that the VSS would have an intermittent problem - but obviously it did. As stated earlier in this post, the speedometer would not work between 0-4 mph which I now believe could also be the reason the abs would occasionally kick in when coming to a slow stop on perfectly dry/clean pavement.

The abs light has since come on a few times so I will now correct the problem with the front left wheel sensor.

 

consider speed sensor on tranny.abs feeds off info from it as well as wheel speed sensors.Also controls speedometer

 

Welcome to Blazerforum.

Notable first post...





j/k