ABS & ATSC lights on

[CC2005]

The following ABS and ASTC lamp issue occurred whilst braking suddenly when doing a low speed left hand turn. A pedestrian stepped in front of the vehicle whilst turning a corner. The ABS appeared to active,( a grinding sound and shudder from left hand front wheel was notice) Estimated speed 15kPh? A minute or so later I noticed the following lamps were illuminated, they may have come on immediately, I'm not sure.

I have noticed when all three lights are on; ABS warning lamp - ON, ASTC OFF indicator lamp - ON, ASTC indicator lamp - ON, the ABS does not function. When all these lamps are illuminated I have no stability control or braking assist. The system in fail safe mode has appeared to lock out these functions when this fault has occurred; according to the service manual this may be a normal precaution upon failure.

Noticed fault events

Sequence 1
Upon start
ABS warning lamp "ON". Turns "OFF" after a few seconds of engine operation.(Normal.)
ASTC OFF indicator lamp "ON". Turns "OFF" after a few seconds of engine operation. (Normal.)
ASTC indicator lamp "ON". Turns "OFF" after a few seconds of engine operation.(Normal.)

Noticed sequence 2.
Engine operating / driving 5 - 10 minutes.
ABS warning lamp Turns "ON". Remains on until engine and ignition is turned off.
ASTC OFF indicator lamp Turns "ON". Remains on until engine and ignition is turned off.
ASTC indicator lamp Turns "ON". Remains on until engine and ignition is turned off.

Noticed sequence 3.
Normal start operation function as per sequence 1.
Then with the engine/driving 5 - 10 minutes. (Have noted longer periods 20+ minutes.)
ABS warning lamp Turns "ON". Turns ON after a (varying) period of time.
ASTC OFF indicator lamp "ON". Turns ON after a (varying) period of time.
ASTC indicator lamp "ON". Turns ON after a (varying) period of time.

There have been the very odd times when the system has operated normally for several short trips in succession, less than 30 minute trips. If the lamps are off whilst the engine is running, the quickest method to cause a failure is to start reversing, reversing to the right.

I have done the basic attempts to rectify the fault. (G and Yaw Sensor) Vehicle on flat ground, front wheels straight ahead - disconnect the battery for 10 - 20 minutes, only a few minutes is required.Sometimes this works, sometimes it doesn't.Fusible links and fuses are good.All stop lamps are working as with the stop lamp switch.

I have not checked the G and Yaw sensor, steering wheel sensor or the wheel sensors as yet. I'm guessing, which I shouldn't, it is a continuity breakdown or possibly a hydraulic solenoid valve fault.

Like some other PB's. My MY11 PB has had the brake pedal sink to "almost" to the floor very slowly, when moderate to light pressure applied to the pedal, generally whilst the vehicle is idling.This may or may not have any relevance.

Firstly I would just like to know if anyone else has had this issue, if so, tell me what was your fault and the remedy, if not, just throw me a few possible scenarios that I should look for first.

I don't have an OBD tool to see what the fault code is, that would probably make life a lot easier. Maybe that will be my next step, getting one of those.

Cheers,

https://s32.postimg.org/qt1yot179/IMG_0651.jpg

[Toddyh]

If you are getting codes definitely get them read. My bet would be wheel speed sensor and/or wiring to the sensor. I've seen the wiring ripped out a few times on either challengers or tritons when a stick gets caught up there.

[old Jack]

Agree with Todd, check wheel rings and sensors, wiring and plugs. Sounds like the system is working correctly but intermittently the ASCTC ECU is getting a faultly signal that is triggering the ASC.

OJ.

[spot01]

Is your car under warranty? Even if not & you bought it new, you still have statutory warranty to seek repair from the dealer.

How old is your battery? Is it holding a good charge? The HBB pump needs good power to operate correctly.

Re brake pedal sinking, when was your fluid last changed? Have you had it bled since this issue started? Does the fluid level drop?

I wouldn't be driving the car until this is fixed.

[CC2005]

Thanks guys for the responses, appreciated.

I have the relevant diagrams, diagnosis sequence and procedures from the service manual, of which include resistance readings of the relevant parts. I'll get on to checking the wheel rings and sensor, steering wheel then G & Yaw sensor and systematically work from there.I'm tempted, more than likely order a scanguage in the hope that this will narrow down the field and pinpoint the error.

The battery is the original although it is still maintaining a very good holding charge, with decent cranking capacity; I ensure that when I check it I'm not just reading the surface charge.

The brake pedal issue was addressed some time back, it actually first failed after a service of which included brake maintenance. The dealer re bled the system.The rare occurrences of the pedal sinking slowly post that service are that, rare, although a known intermittent issue for some.I cannot replicate it by manual means.I have not experienced this for a long time or whilst this current issue has been present.Fluid level is good and does not drop.

I purchased it in 2011 with 15K on it and it is out of warranty with only 25K on the clock. (It should have by now had another 70K on it - another story.) I don't have an issue perusing the issue as warranty, but first I need to substantiate that it falls into an arguable warranty category case first.

Cheers,

[RMX]

If it helps and depending on your location on the peninsular, I work in Chelsea Heights and have an OBDII reader in my Challenger.

If you want to bring it this way, I can read the codes for you and give you an idea of what the issue is, and clear them if you wish.

[CC2005]

If it helps and depending on your location on the peninsular, I work in Chelsea Heights and have an OBDII reader in my Challenger.

If you want to bring it this way, I can read the codes for you and give you an idea of what the issue is, and clear them if you wish.

Hi RMX

I greatly appreciate your offer. In order not to waste any of your time I'll get off my ar5e and do some of the basic checks this first. Ohms readings for each of the wheel sensors.


I'll let you know how I get on with those and the other connectors.


I'll start checking each of the wheel sensors from the A-68 connection at the ASTC-ECU. From A-68 connection the preliminary check is straight forward. If I encounter any issues with any of the sensors, I'll then do an individual loom isolation check starting with the relevant sensor.


From the schematics and connector layout it will be pretty straight forward. From the general layout schematic there appears to be a diagnosis connector for the ABS ECU also.


Again I very much appreciate your offer.

Cheers,
Craig

[old Jack]

Hi Craig,

Make sure you only stick the multimeter probes into the back of the plug where the wire enters as the plug contact surfaces are extremely fragile and the ECU's are hyper sensitive to any change in resistance. You can cause more problems than you find if you are not careful.

OJ.

[CC2005]

Again guys I appreciate the advice & offer of assistance.

OJ,
Thanks for the warning although I was already into it. I had borrowed a gauged set of gold plated tapered contact probes/pins with flying leads as used for electronic circuit board work for a similar purpose.


Verdict: One front wheel speed sensor reading 0.08 k Ohms, the required range 0.9 - 1.3 all the others were over 1.0k. I also checked the continuity from the wheel speed sensor connection back to the ABS- ECU connector and it is ok. So when I get a moment, I'll remove the sensor and check the wires for damage. I could not see a mark where something may have come in contact with it or its loom. At worst a new sensor, but at 25k this is a bit of bad luck considering it has had an easy life.


Thanks

[CC2005]

I'll add information to this thread when it becomes available. It might just help someone.

I have been informed that the front wheel speed sensors are not all the same for all PB & PC (KH) Challengers. My enquiry was for a front right only, although I was informed it applies for both sides.

Build range 01/11/2009 to 30/07/2011
Front Right Hand Wheel Sensor: P/N MN102574
Front Left Hand Wheel Sensor: P/N MN102573

Rear Right Wheel Sensor: P/N 4670A260
Rear Left Wheel Sensor: P/N 4670A259


Next date series 01/08/2011 to 30/10/2013
Front Right Hand Wheel Sensor: P/N 4670A596
Front Left Hand Wheel Sensor: P/N 4670A595

Rear Right Wheel Sensor: P/N 4670A600
Rear Left Wheel Sensor: P/N 4670A559


The person that assisted me stated, he had supplied these (front) for Triton's before although he personally has never supplied one for a Challenger. He thought it was somewhat odd in my situation with my vehicle having done so few km's.

[CC2005]

For those who may need a new sensor.

Front, MMA will ask in the vicinity of $245.00 for an OEM item. Some overseas suppliers that I have contacted will supply an OEM item delivered to Aus; $180.00 to $240.00 approx.

Non OE items, if you trust them, can be obtained delivered into Aus; $30.00 to $180.00. A few suppliers will try to make you believe they supplying an original item, very few have specifications listed. I have asked several for simple measured resistance readings, and have received none.

Second hand, so far approx $55.00 to $80.00 plus delivery.

(Some of the rear sensors, some are shared with Chrysler vehicles.)

And apparently there is differences between the sensors dependant on VIN date range as pointed out above, so check first. I have been told there are harness bracket and connection mount configurations differences, and sensor differences, although I cannot confirm this as the information differs depending on who you talk to.

[coughy]

ty for the info can maybe a mod sticky this info pls
as i feel there is going to be a lot more of these little suckers playing up soonish

[CC2005]

I never got around to updating this. My situation I suspect was caused by a 4x4/come suspension specialist re installing my front suspension for the 3rd time, still ain't right. In the process they bent the sensor wire harness bracket closest to the front RH drive axel. The result was the cable was intermittently scrubbing against the uni rubber boot and abraded partially through the insulation severing one wire. Upon my first inspection I did not see the worn section, yet it was so obvious upon my second inspection.


The white and black sensor wires are encased in a very firm black outer plastic type sheathing of which is hard to trim with a sharp blade, so opening it up can be tricky as it is very easy to trim and cut into the very soft insulation of the sensor wires-exactly what I did. I trimmed and joined my broken white wire, replacing a small section, in the process, I f*&^d the black wire of which then had to be re-joined. Some handy (amateur) solder and insulation work the sensor was back within the 0.9-1.3 ohm spec range and I was temporarily set to go again. - still haven't replace it more than a year down the track.

[littleriver]

I never got around to updating this. My situation I suspect was caused by a 4x4/come suspension specialist re installing my front suspension for the 3rd time, still ain't right. In the process they bent the sensor wire harness bracket closest to the front RH drive axel. The result was the cable was intermittently scrubbing against the uni rubber boot and abraded partially through the insulation severing one wire. Upon my first inspection I did not see the worn section, yet it was so obvious upon my second inspection.


The white and black sensor wires are encased in a very firm black outer plastic type sheathing of which is hard to trim with a sharp blade, so opening it up can be tricky as it is very easy to trim and cut into the very soft insulation of the sensor wires-exactly what I did. I trimmed and joined my broken white wire, replacing a small section, in the process, I f*&^d the black wire of which then had to be re-joined. Some handy (amateur) solder and insulation work the sensor was back within the 0.9-1.3 ohm spec range and I was temporarily set to go again. - still haven't replace it more than a year down the track.

great to hear you fixed it ... (was wondering what had happened) ...

Suspension expert fitting suspension x3 times that's a laugh ...

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