bigbangtech

Initially had a Front Right ABS Sensor SHORT error code after driving. Replacing sensor didn't fix it. new and old sensor measured 1.18 kohms at the sensor, and at the ABS actuator connector.

Traced wire and checked for opens/shorts/high/low resistance, it's good from sensor to abs actuator

Scan tool shows Front Right sensor at 0MPH until you hit around 30mph, then front right sensor shows 14mph.

Opened up the big gray abs actuator wire connector, cleaned out any crud, cleaned with electronics cleaner, put a little electronics grease on pins, reseated connector.

NOW, front right sensor (SHORT) error code went away. But instead, now I have a REAR right sensor error code (OPEN). WTF?

To top it off, now the scan tool shows BOTH the FRONT and REAR right sensors at 0MPH until you get to around 30MPH, then only FRONT RIGHT sensor shows 14MPH or so. REAR RIGHT sensor shows 0MPH, did not bother trying to go faster.

So to boil it down, now both right sensors are showing the wrong speed and rear shows open error code.

At my wits end here. Could the control board in the ABS actuator be going bad? How to even diagnose this, FSM just says to check for ground and power at abs connector and that's about i?

bigbangtech

I ordered an abs pump from ebay for $50 that looked brand new and was low mileage. Replaced the pump and bled the system. Same results.

Short error code on Front Right wheel sensor, just like before. Plus intermittent Open error codes on random wheels.

I figured out the random intermittent Open codes however - I applied dielectric grease on the abs connector - dielectric grease is an electrical insulator, so when added to the poor mechanical connection of the abs connector pins, random Open error codes would happen when the abs connector was jiggled even slightly. Cleaned the connector pins and the Open codes are gone.

Still left with Short error code on Front Right wheel. I've eliminated a lot of things and running our of possibilities. Here's what I've eliminated:

ABS pump/controller - replaced with different unit, same Short error code - this is an unlikely cause

CV Axle w/Sensor Ring - changed to a new one axle, same Short error code, swapped another unit, same Short error code

ABS Sensor - changed to brand new, both old and new measure 1.18kOhm, within spec

Wire between ABS Sensor and ABS pump - measured 1.18kOhm per spec. I also ran a completely new wire here, same Short Error code - this is not the problem.

ABS Sensor/ Sensor Ring clearance (air gap) - right in the middle of allowable range.

The absolute last variable I can think of is the steering knuckle - it holds the ABS sensor in proximity to the Sensor Ring on the cv Axle - I replaced the knuckle because the bearing had gone bad. I started getting the Short error code after changing the cv axle and steering knuckle together. The sensor clearance is within spec, but what if it's off center in relation to the sensor ring? When driving, my scan tool shows all 4 abs sensor speeds in mph.

This front right wheel shows 0mph until the other wheels start showing about 20+mph...