SOLVED - ABS light on after new front hub assy install(both sides)

[CrazyDiamond]

2002 Tahoe LT 5.3L
We're in the process of changing out parts after 240k mi. Rear end and front suspension parts all new install. While doing those changes, we put in new MOOG hub assy (includes new sensors). We still need to have it aligned but, otherwise, all work is completed.
We are having issues with the ABS light staying on and periodically some odd braking activity when testing; brake petal goes hard and have to press super hard to stop (doesn't go to floor).

Pulled the codes. Test 1 results: C0227, C0223, C0269, C0221, C0222, C0225, C0226. Test 2 results: same as first test plus C0229. Tests included low speed and high speed (55+) braking to engage the ABS as well as normal braking.

Prior to new install, ABS light was NOT on and no braking issues were occuring.

Hubby reinstalled old sensors to test if ABS light would go off and it did not. We have also reset vehicle computer via gas pedal stomp, reset battery, and ignition reset method (I thought it was gas pedal reset but when that didn't work, he just went ahead with all other).

He is currently testing ohms on old and new sensors as well as harness plug.

What are we missing? No idea why both sensor sides would be coding. Understood that it could be ECBM but, again, why would it suddenly go out when we weren't having any braking issues before. I don't want to just throw money at it unnecessarily.

I couldn't find anything in the forums so I apologize if this has already been addressed somewhere here. Thanks to everyone!!

 

[Alessandrolomb]

MOOG is usually a solid brand, but sometimes you can get a bad part. If the hub bearings aren't made right or they have a flaw, it might mess up the built-in ABS sensors. If I were in your shoes, I'd check the output from each sensor while spinning the wheels to see if the readings are off.

 

[CrazyDiamond]

FYI, ohm readings are inconclusive.

 

[CrazyDiamond]

MOOG is usually a solid brand, but sometimes you can get a bad part. If the hub bearings aren't made right or they have a flaw, it might mess up the built-in ABS sensors. If I were in your shoes, I'd check the output from each sensor while spinning the wheels to see if the readings are off.

Ok, test 2 was with the code reader plugged in while driving but we can do it manually in our garage. I see what you're saying about it so we can check that.

 

[Doubeleive]

2002 Tahoe LT 5.3L
We're in the process of changing out parts after 240k mi. Rear end and front suspension parts all new install. While doing those changes, we put in new MOOG hub assy (includes new sensors). We still need to have it aligned but, otherwise, all work is completed.
We are having issues with the ABS light staying on and periodically some odd braking activity when testing; brake petal goes hard and have to press super hard to stop (doesn't go to floor).

Pulled the codes. Test 1 results: C0227, C0223, C0269, C0221, C0222, C0225, C0226. Test 2 results: same as first test plus C0229. Tests included low speed and high speed (55+) braking to engage the ABS as well as normal braking.

Prior to new install, ABS light was NOT on and no braking issues were occuring.

Hubby reinstalled old sensors to test if ABS light would go off and it did not. We have also reset vehicle computer via gas pedal stomp, reset battery, and ignition reset method (I thought it was gas pedal reset but when that didn't work, he just went ahead with all other).

He is currently testing ohms on old and new sensors as well as harness plug.

What are we missing? No idea why both sensor sides would be coding. Understood that it could be ECBM but, again, why would it suddenly go out when we weren't having any braking issues before. I don't want to just throw money at it unnecessarily.

I couldn't find anything in the forums so I apologize if this has already been addressed somewhere here. Thanks to everyone!!

looks like you might have a open circuit if one of the vehicle side connectors for the abs sensors is corroded or broken, or broken wire (like harness got pinched or pulled hard that could cause the issue. check the vehicle side connectors and check for continuity.

 

[CrazyDiamond]

looks like you might have a open circuit if one of the vehicle side connectors for the abs sensors is corroded or broken, or broken wire (like harness got pinched or pulled hard that could cause the issue. check the vehicle side connectors and check for continuity.

Hi Wes, he checked the ohms on the harness and was inconclusive difference. I attached the ohm testing results above. So frustrating...

 

[CrazyDiamond]

Is it possible that since we haven't had it aligned yet that the wheel camber (looks a little off) could cause the error? The vehicle drives straight since he took pre-emptive measure to prevent it from being way out of wack but, nonetheless, it does need alignment.

 

[Ont240]

Nothing to do with alignment.

 

[Doubeleive]

Hi Wes, he checked the ohms on the harness and was inconclusive difference. I attached the ohm testing results above. So frustrating...

Hi Wes, he checked the ohms on the harness and was inconclusive difference. I attached the ohm testing results above. So frustrating...

Check the vehicle side harness connector pins with key on and see if one side reads different than the other.
also wiggle the wire while checking to see if a break occurs

 

[Doubeleive]

Conditions for Running the DTC
C0221 and C0225
The ignition is ON.

C0222, C0223, C0226 and C0227
The vehicle speed is greater than 32 km/h (20 mph) when the brake is applied or 19 km/h (12 mph) when the brake is released.

Conditions for Setting the DTC
C0221 and C0225
The the EBCM detects an open or shorted wheel speed sensor or wheel speed sensor circuit for 500 milliseconds.

C0222 and C0226
The corresponding wheel speed sensor signal is less than 6 km/h (4 mph) for 5 seconds (120 seconds in order to set both DTCs).

C0223 and C0227
The EBCM detects an erratic signal from the corresponding wheel speed sensor for 105 milliseconds.

Action Taken When the DTC Sets
C0221,CO225
If equipped, the following actions occur:
^ The EBCM disables the ABS/TCS.
^ The ABS indicator turns ON.
^ The TRACTION OFF indicator turns ON.

C0222, C0223, C0226, and C0227
If equipped, the following actions occur:
^ The EBCM disables the ABS/TCS and may disable DRIP.
^ The ABS indicator turns ON.
^ The TRACTION OFF indicator turns ON.
^ The red Brake warning indicator may turn ON.

Conditions for Clearing the DTC
^ Repair the condition responsible for setting the DTC.
^ Use a scan tool in order to clear the DTC.
^ After the DTC is cleared and the ignition is ON, the ABS indicator may remain ON until the EBCM completes a power-up self-test. This test concludes when the vehicle reaches a speed greater than 13 km/h (8 mph) and the wheel speeds are verified by the EBCM.

 

[nonickatall]

Measuring ohms makes no sense, ABS sensors can only be measured with an oscilloscope.

If you have unplugged the old ABS sensor and plugged the new one in correctly, it should work.

Normally the sensors need to travel a few meters to register with the car and for the ABS error to go away.

If this doesn't happen, either the new ABS sensor is defective or you have damaged the cable.

 

[CrazyDiamond]

Measuring ohms makes no sense, ABS sensors can only be measured with an oscilloscope.

If you have unplugged the old ABS sensor and plugged the new one in correctly, it should work.

Normally the sensors need to travel a few meters to register with the car and for the ABS error to go away.

If this doesn't happen, either the new ABS sensor is defective or you have damaged the cable.

Thanks for your help. The vehicle has been driven for miles already during testing.
The diagnostic codes indicate both sides throwing codes and the sensors come as part of the new MOOG hub assy so I find it hard to believe that both sides would be faulty.
Also, as diagnostic test, we unplugged the MOOG sensor and plugged the old one back in...the ABS light didn't clear. However, it is true that we did not drive it to see if it would clear at that point because we didn't want to have to do all the parts off and on, etc. until we could fully test other things first.

 

[CrazyDiamond]

We need to clear the codes and run a live diagnostics test while driving again, which we will probably do tomorrow. And other things y'all have mentioned. With all the other work done, my hubby can barely move from pain, as he has back issues. But we will live to tell another day. ;-)

 

[CrazyDiamond]

Update: we discovered that the dust covers were put on backwards and possibly putting pressure on the sensor, which would cause it not to read correctly. Pulling everything off to fix that first to see if that might be causing the issue. Then going from there...

 

[CrazyDiamond]

Final update: fixed dust cover placement and that solved the issue. Placement was putting pressure on the sensor so it wasn't seating correctly. We did have to replace one of the sensors because it was likely damaged during this process. Put old sensor on and solved the problem. We'll get another new MOOG sensor so we have all new parts.
Lesson learned: make sure to put the dust covers on facing the correct way. ;-D

 

[CrazyDiamond]

Thanks everyone for your time and help!