pboglio
20+ Year Contributor
- 1,801
- 90
- May 8, 2004
-
Palos Heights,
Illinois
I've searched far and wide on both tuners, ecmlink forums, and dsmtalk and found very little information on effective troubleshooting of the 2g abs system. Most people seem to be content living with no abs and/or pulling the abs light bulb out. Due to my Illinois emissions testing requirements, and the fact I actually like having a working ABS system, those weren't options for me.
To preface this story, I'll go back about a year. I happened to be going about 80 mph on the expressway one day tuning my ride and had to hit the brakes fairly hard. What happened next surprised me a little bit, as the right rear end started stepping out and tried to swap ends with the front. Now, I knew this was the ABS system kicking in, so I proceeded to pull the abs fuse. Problem never occured again. However, having no ABS absolutely sucks in the snow and rain. Anyhow, time to get emissions checked and what do you know, an ABS light is an offense that can get you a failed emissions.
At this point I decide, I'll put the ABS fuse back in since although the ABS doesn't work right, it never flashed the abs light. Nope, once I start rolling I get a solid ABS light. I decide to break down and physically check the following items:
G-sensor: 2.5 volts flat orientation, 3.7 volts facing down, check.
Hydraulic unit: directly powered off battery voltage, check.
Hydraulic motor relay: activates with 9 volt signal, check.
Valve relay: activates with 9 volt signal, check.
ABS ecu: good, I get the 4 quick ABS flashes on startup.
Power relay: works fine, powered the g-sensor with 11.65 volts, check.
Solenoid resistance: 1.3 ohms, check.
ABS sensor RR: 1.6 kilo ohms, a little higher than the 1.0-1.2 kilohm nominal.
ABS sensor RL: 1.6 kilo ohms.
ABS sensor FL: 1.6 kilo ohms.
ABS sensor FR: 1.6 kilo ohms.
ABS sensor RR: 0.016 volts at 40 mphWTF
ABS sensor RL: 7.6 volts at 40 mph
ABS sensor FR: 3.4 volts at 40 mph
ABS sensor FL: 3.70 volts at 40 mph
Bingo, 0 volts in the ABS right rear sensor. But it passed the resistance check. Based on research, it could have been: corroded toner ring gear teeth, metal shavings on the abs sensor, etc. So I decide that a visual check was in order. Well, I look at that toner ring on the right rear and sure enough, it looks like it walked itself off the rear axle and away from the sensor probe. I touch it with a screwdriver and it moves freely.
Parts to be ordered:
1) Rear axle
2) Rear wheel hub & wheels studs
3) ABS RR wheel speed sensor (precautionary measure)
Without an ABS diagnostic tool I spent an enormous amount of hours checking the abs harness and sensors. I think I dedicated about 18 hours to checking everything as best I could with a multimeter.
I have no doubt in my mind that the Ksport coilover that blew out on the right rear punished that side of the car so badly it caused the toner ring to pop off. In fact, this particular suspension also caused my shifter cable bracket bolts to walk loose as well. Another reason I despise these coilovers and a good excuse to put some real struts and springs in the car.
Hope this helps anyone who has had issues with their abs system.
To preface this story, I'll go back about a year. I happened to be going about 80 mph on the expressway one day tuning my ride and had to hit the brakes fairly hard. What happened next surprised me a little bit, as the right rear end started stepping out and tried to swap ends with the front. Now, I knew this was the ABS system kicking in, so I proceeded to pull the abs fuse. Problem never occured again. However, having no ABS absolutely sucks in the snow and rain. Anyhow, time to get emissions checked and what do you know, an ABS light is an offense that can get you a failed emissions.
At this point I decide, I'll put the ABS fuse back in since although the ABS doesn't work right, it never flashed the abs light. Nope, once I start rolling I get a solid ABS light. I decide to break down and physically check the following items:
G-sensor: 2.5 volts flat orientation, 3.7 volts facing down, check.
Hydraulic unit: directly powered off battery voltage, check.
Hydraulic motor relay: activates with 9 volt signal, check.
Valve relay: activates with 9 volt signal, check.
ABS ecu: good, I get the 4 quick ABS flashes on startup.
Power relay: works fine, powered the g-sensor with 11.65 volts, check.
Solenoid resistance: 1.3 ohms, check.
ABS sensor RR: 1.6 kilo ohms, a little higher than the 1.0-1.2 kilohm nominal.
ABS sensor RL: 1.6 kilo ohms.
ABS sensor FL: 1.6 kilo ohms.
ABS sensor FR: 1.6 kilo ohms.
ABS sensor RR: 0.016 volts at 40 mphWTF
ABS sensor RL: 7.6 volts at 40 mph
ABS sensor FR: 3.4 volts at 40 mph
ABS sensor FL: 3.70 volts at 40 mph
Bingo, 0 volts in the ABS right rear sensor. But it passed the resistance check. Based on research, it could have been: corroded toner ring gear teeth, metal shavings on the abs sensor, etc. So I decide that a visual check was in order. Well, I look at that toner ring on the right rear and sure enough, it looks like it walked itself off the rear axle and away from the sensor probe. I touch it with a screwdriver and it moves freely.
Parts to be ordered:
1) Rear axle
2) Rear wheel hub & wheels studs
3) ABS RR wheel speed sensor (precautionary measure)
Without an ABS diagnostic tool I spent an enormous amount of hours checking the abs harness and sensors. I think I dedicated about 18 hours to checking everything as best I could with a multimeter.
I have no doubt in my mind that the Ksport coilover that blew out on the right rear punished that side of the car so badly it caused the toner ring to pop off. In fact, this particular suspension also caused my shifter cable bracket bolts to walk loose as well. Another reason I despise these coilovers and a good excuse to put some real struts and springs in the car.
Hope this helps anyone who has had issues with their abs system.
