Ziggie

Hi,

Here is how I fixed ABS problems on 2008 Chevy impala.
Tools & aids:
I-pad with connection to schematics on AUTOZONE
magnifying glass to read the pin numbers on the ABS computer connector
Soldering station, soldier
heat shrink tubing of appropriate size
heat gun, electric tape
5' of wire, 22 Ga, to run the continuity test from the ABS computer connector to wheel sensor connectors

Time: 3 hours, cost $0.0, problem solved

Problems found, broken one wire on the left front sensor, very close to the connector, able to fix and not replaced the bearing/hub assy for now,
broken both wires on the right on the harness inside the tubing about 10" inches from the hub connector, able to fix.

Ziggie

Ziggie

Some more pictures, they did not come out good.
Remember that the fix was possible due to simple continuity tests with ohm meter and right information available (wiring diagram).


Ziggie

Ziggie

My buddy has one more problem with this 2008 Impala, MIL is on and code is P0452,Fuel Tank Pressure Sensor output low, but I am educating myself on this, possible FTP sensor, but I am not sure, understand only 50% of this evaporative system. FTP sensor I can test on the bench (Fuel Tank Pressure Sensor), it is a simple absolute pressure sensor, on the bench I can apply 5 volts to it and look at the output, with no vacuum output should be close to zero volts, with vacuum applied (with a hand vacuum pump or vacum cleaner LOL, the output voltage should go up.
I do not have an info as for the actual values but can test and compare good to bad one. I think this is more of a leak than sensor, so I will check the gas cap hoses etc, next time I'll see the car.

Ziggie

Mikes09

Ziggie,
Thanks for your post--I just did the same repair on my '09 Impala using your test method. Had already replaced the wheel bearing, but still had the ABS/traction control problems. Dealer had previously "fixed" this problem over a year ago with a poor soldering job which I just discovered. I can't believe what a fragile system of wiring is used for this sensor!!!! It is destined to fail......

Really appreciated your effort on reporting your solution.

SS-Driver

Ziggie,
Thanks for your post - I just did the same repair on my '08 Impala using your method. You inspired me!


I had to find the pin-out assignments for the 30-pin ABS module connector and the schematic on Autozone, but that was just a minor setback. For all those checking in - I had no continuity on either of the right wire harness wires.


When I pulled the connector wire and sheathing - water came out. When I cut back the water-protective sleeve, the wires were wet and looked like they have been wet for a long time. in the 10-inch section that I replaced from the wheel connector, there was what appeared to be a factory splice in the wire set. Odd. I suspect the wires corroded within their sleeves because there were NO SIGNS OF EXTERNAL DAMAGE, but the wire felt "whimpy".


For reference, I found this on another website:
With the plug end of the connector facing you you want to check the wiring to each wheel. There may be VERY small numbers moulded into the corners of the plug. Looking at the plug end of the connector the numbers start at 1 in the upper right side ending in 11 upper left side. The last row starts with 20 in the lower right & ends at 30 in the lower left.
#2 & #3 pins Right rear wheel
#4 & #5 Right front wheel
#20 & #21 Left Front wheel
#22 & #23 Left rear wheel.



Thanks again!
No $$$.$$ for the stealership!

tech2

not the best way but it is a cheap temporary fix.


gm does not want their techs to repair this fault this way. It will fail again, just a matter of time.


abs wiring is a specific type of stranded wire. It is very fine, has more strands and is designed to flex. Soldering or butt connectors out the back of the connector; the solder or butt connector can't flex. the wiring will break just past the repaired area.


the proper way is to splice in a repair harness (available from dorman $30-$40...if you hate dealers) that is connected in an area of the harness that is fixed...ie no where near the control arm.

Jakespeed63

Found this thread, while trying to diagnose an intermittant C0040 RF wheel speed sensor circuit erratic issue.
(2009 Chevy Impala Police pkg)
Despite no visible signs of chaffing or breakage, the RF ABS harness had to be the fault. We ordered the Dorman #970-040 repair harness and it fixed the problem!!
Please note, I highly recommend using the provided heat shrink butt connector. DO NOT solder these connections. It will fracture down the road.
Thanks again for saving me time and aggravation. Almost replaced the entire front engine harness, which would have been a nightmare.
JT
City of Winter Park Fleet Maintenance.

2006 impala

Giving me a heart attack

tech2

false. the recommend repair method by manufacturers is a mechanical crimp using a open barrel connector, then soldering with rosin core solder, then heat shrink tubing, then wrap in anti abration/ tesa tape.

shrink tube in meant to seal the repair from corrosion. it has no mechanical strength to keep the splice together.

niceguy88

Hey guys, apologies for the big bump but there seem to be relatively few useful threads on the net about this gm sensor harness problem, and I seem to have the same issue on my Uplander right front. I've had the same persistent ABS/Traction codes the last 6+ months and testing the chassis side of the abs sensor harness connector, I'm getting infinite resistance. But regarding the pigtail harness, where are you splicing it in? Are you guys unwrapping the sensor harness sheathing until you find an obvious break/bad spot or just cutting back to a safe place where the harness is fastened down?
I'm also pulling a c0131 but plan to double check the fluid levels and bleed the system before I even consider dumping big $$ into the ABS system. Van runs great otherwise with no strange braking behavior.

Thanks guys