ABS engages way too often!

[rpg]

'07 Silverado with 38k (maybe I don't drive it enough)

Recent problem when approaching a stop where the ABS appears to engage. Pulse is felt in the pedal and it obviously increases the stopping distance. Does this about 40% of all stops and between 5-10mph approaching the stop.

Haven't rear ended anyone yet, but on dry 100 degree Detroit pavement, I wouldn't think the ABS would be engaging prematurely.

No error codes with a OBDII scanner and the brakes appear to operate and are otherwise smooth. And I flush my brake fluid annually.

thanks for your help,

RPG

[j cAT]

Originally Posted by rpg

'07 Silverado with 38k (maybe I don't drive it enough)

Recent problem when approaching a stop where the ABS appears to engage. Pulse is felt in the pedal and it obviously increases the stopping distance. Does this about 40% of all stops and between 5-10mph approaching the stop.

Haven't rear ended anyone yet, but on dry 100 degree Detroit pavement, I wouldn't think the ABS would be engaging prematurely.

No error codes with a OBDII scanner and the brakes appear to operate and are otherwise smooth. And I flush my brake fluid annually.

thanks for your help,

RPG

remove the front wheel sensors ..see if the grease is red, should be blue...see if the mounting hub surface has pushed out the sensor ..sensor mounting surface must not be rusted...measure the voltage at the sensor connector, should be 350MV AC or more with you rotating the hub by hand at at good rate of speed..

[danielsatur]

Is the air pressure the same is all tires?

[procaddytech]

Follow j cAT's suggestions. One of the front sensors is dropping out, due to excessive air gap. The lowest they read in the module is 3mph. The usual dropout point is 5 - 8mph. The sensors read ok at all other speeds so no dtc's will set. The module "sees" the wheel as locking up so it engages the abs. Make sure the hubs are tight when you raise the front. If one is loose, get a new one and it will come with a sensor. Gently twist and pull up on the sensor to remove it, do not pry it or it may break off in the hub. Put something in the sensor hole while you clean the mounting surface on the hub so no metal or rust gets in the hole. Don't forget to remove it. Clean the sensor, apply grease on the o-ring, reinstall and make sure it is flush with no gaps. If the sensor is warped, it will need to be replaced. This procedure will solve the false engagement most every time.
Gm actually issued a campaign/recall for certain 1999-2002 trucks for this concern.

[1996ctnc]

Could this be a solution to a similar problem I am having on my 1999 K3500 j cAT? Almost sounds like the same symptoms I have been having. I have hydro boost system and have replaced power steering pump.

[j cAT]

Originally Posted by 1996ctnc

Could this be a solution to a similar problem I am having on my 1999 K3500 j cAT? Almost sounds like the same symptoms I have been having. I have hydro boost system and have replaced power steering pump.

The issues with the ABS activating at low speed , is normally from the front hubs being damaged from the grease/weather seals rusting out then the bearings create metal rust that fouls the magnetic speed sensor pick up head. I would start by removal of the sensor and check for rusted grease/rust on the sensor head. now what I would do if you find this the case, replace the front hub[s] [use Timken] or if your short on cash now using a grease gun pump up the hub with grease until it blows out the grease seal in the back[use sensor hole]. this should work for a 1-3 month period. this will push out the rusted grease and give you more time to get this repaired. I would also at this time spray down the hub control arm area with rust buster/or some other specialty penetrating oil. then this will aid in the hub removal as they do get rusted in place...

good luck ...