ABS & Cruise control, any relations?

[bigrockk]

2007 GMC 2500HD 6.0L 145,000 miles

Recently my ABS light starting coming on intermittently, it usually stays on until I shut the truck off, then when I start a new drive cycle it will go off for awhile and then come back on, most times after I hit some bumps in the road.
I have a code reader but unfortunately it isn't capable of scanning ABS codes.
I did jack up the truck and checked for play in the wheel hubs, they seem good and tight as far as I can determine. I also checked the resistance of the wheel speed sensors and they seem OK as well, one was 1080 ohms and the other was about 1030.I spun both wheels and measured about the same AC voltage on both wheels.

Also right around the same time my cruise control has started to act up, it just kicks out randomly while driving, sometimes it will be OK for long stretches and sometimes it will kick off repeatedly. I can always hit the resume function and it will resume to the preset speed again.
The only thing I tried in regards to the Cruise control was hooking my foot under the brake pedal and holding it up it case it had something to do with the brake switch but that didn't seem to cure anything.

So now I am wondering if there is any kind of relationship between the cruise control and the ABS light,or is this just a fluke that they both failed right around the same time?
Appreciate any thoughts.

[j cAT]

You need a scan tool ................that reads abs codes .. Then post them.

[bigrockk]

Thanks for the reply " j cAT"

Might take me awhile but I am working on getting the codes, looking to purchase one of the scan tools listed below, leaning towards the "DIY Version of the Autel MD802" but not 100% sure yet.
Any way as soon as I get those codes I will post back.

Autel AL619 OBDII/CAN Scan Tool
New DIY Version of the Autel MD802)
Autel Maxilink ML629 AL629

[j cAT]

Originally Posted by bigrockk

Thanks for the reply " j cAT"

Might take me awhile but I am working on getting the codes, looking to purchase one of the scan tools listed below, leaning towards the "DIY Version of the Autel MD802" but not 100% sure yet.
Any way as soon as I get those codes I will post back.

Autel AL619 OBDII/CAN Scan Tool
New DIY Version of the Autel MD802)
Autel Maxilink ML629 AL629

I have the actron 9680 .. tool is update able no cost.
I was thinking of getting the cp9690 as this newer model comes with OBD I capability and reviews of this look good . cost around $200..USD.
the CP9680 which has been around a few years is about $170...
I have found this tool great ,as I can chart out the O2 sensor voltages and other data.. my only issue is it is not with good info , on how to get the MAX use out of the tool .. manual is weak on this , it is update able free .. AUTEL free for only 1 year..

the tool does have a battery power as back up so if the vehicle has no power at plug it helps tell you whats up...

the battery's do drain quickly so I rarely turn tool on when not connected or I just operate the tool with NO batteries in it ..

I believe advance auto has these in stock so you can check them out ,but the cost is higher if you purchase from them..

[j cAT]

the intermittent ABS light issue is IMO a connection issue .. very common .. PCM can not see the air bag so light comes on. old vehicles this is has not been a problem . the materials used on newer are very cheaply made esp GM 2008 and newer on wiring/connectors etc..

connection issue maybe in the steering column ...............

[kenman1717]

what is the condition of the ground under the drivers door on the cab mount bracket. those are so common and abs and cruise sometimes both ground here, but not always. have fixed this same issue on other 2007 models by redoing this ground, but that was after all other suspect eliminated. just a thought, it doesn't always fix the cruise, but it goes along way with the abs, have got certain codes before, and in the diagnostic process it says check and repair this ground.

[bigrockk]

@ j cAT: Thanks for the scan tool info, I will check them out, I'm north of the border so no Advance Auto parts for me I really like the fact that updates are free for life from Actron.
I will check the connections that I can for now and will get more serious once i get the scan tool. Thanks again!

@kenman1717 I will check that out as well and post back, appreciate the info!

[bigrockk]

Well finally got the codes. Even though the ABS light was on I had no "active" codes.History showed C0035 and C0040. I figured I might have caused these codes when I was checking the sensor resistance and the AC output so I cleared them and went for a drive.
Didn't take that long, after hitting a few bumps and the ABS light came back on.
Scanned for codes again and I now have a C0040 code.

So at least I know now it's the right/front WSS circuit.

Hey j cAT as a side note I ended up with a "Launch EasyDiag plus 2" code scanner. Its just a bluetooth dongle that pairs with your cell phone. I bought it because I couldn't find the Actron locally and the "NAPA guy" recommended it. It was a pain to set up but seems not bad now. It won't give me "live data" from the wheel speed sensors but at least I got the codes.

@kenman1717 I cleaned up those grounds but the problem persists. I did come across a TSB with the same info so most likely cleaning them up prevented future problems!

[j cAT]

since you have the c0040 code that means the circuit is shorted or open .. that will require that the wires and sensor be checked . most times a lifted truck will cause this. also this is a required sensor for ABS .. so the abs light should come on immediately..

a $200 scan tool will not be able to read the volts from these sensors , but will give you the codes so you can be directed to troubleshoot the component area.

if you remove the sensor connector at the wheel well and when spinning the hub get 350MV AC or more then the wiring is messed up somewhere back to the PCM... normal output should be 500MV AC .5volts AC...

[kenman1717]

if your getting a code for one of the wheels, redoing that ground usually won't fix it, but your right it is a good preventative maintenance. Depending on year that ground effects a lot of things. I have fixed to many things but just cleaning up that ground that I don't ignore it. I don't always clean it, depending on what condition its in, but trust me it does help in the long run. So now that you have a direction the best of luck, hopefully its just a sensor, if its in the truck side of the wiring that can be a pain unless its easily accessible.

[bigrockk]

Got lucky! Unplugged the right WSS and observed my ohmmeter while wiggling and pulling on the cable. Bingo, saw the ohmmeter "jumping around" as I was moving the cable and found it rubbed thru near the hub.

Repaired as best as I could and its seems to be working fine now. If it acts up again I will just replace the sensor.

Thanks guys, appreciate the help.

[j cAT]

the repair of wires should be soldered . then apply some liquid tape to seal the area.. if the wire was cut then a piece of shrink electrical tubing over the joint repair .. use heat to shrink the tubing sealer .. any water will corrode that repair so it must be protected ..

on the sensor replacing a scrap yard would be the cheapest as these sensors are expensive. also if your sensor has some shims use those shims as the replacement may hit the hub encoder teeth.. good luck with it.

[bigrockk]

Thanks for the info j cAT, Good stuff!