ACS fault help

[Sean d]

I still have the ACS issues guys, the fault I am getting is code 50 throttle actuator, I swapped it today for a used one, took the car out and first bend I slid the rear and no light came on even though the wheels spun, gave it some beans on the straight and the rear stepped out, the light came on and didn't go out, it does reset itself with ignition, the butterfly feels nice and free,
Could this be related to the solder in the module, I beleive they are prone to breaking, @Antm72 did you have a similar issue
@Murray Wall any ideas pal

 

[mrscalex]

Don’t forget any particular code could be the part as indicated.

Or the wiring loom or as you say ABS module giving a false indication.

 

[t-tony]

Ant's problem was ABS related as I remember. Have you checked the speed sensor on the Diff. Sean? Remove, clean check connections.

Tony.

 

[Sean d]

Don’t forget any particular code could be the part as indicated.

Or the wiring loom or as you say ABS module giving a false indication.

I have changed the part that was indicated Robert

 

[Sean d]

Ant's problem was ABS related as I remember. Have you checked the speed sensor on the Diff. Sean? Remove, clean check connections.

Tony.

I did have a diff code a while back but I assumed that was because it was disconnected when I dropped the rear subframe, it cleared ok and has not resurfaced pal

 

[Mario]

Sean - when you turn on the car the ASC should go through a self check that closes and opens the butterfly - is it doing that?

 

[Mario]

Been reading a bit about this out of curiosity - what I would do is - do the startup self check but with the throttle body connected but not attached to the intake boots so you can actually see if the butterfly actually moves, maybe the electrical connections are OK but somehow the butterfly is not moving or not moving fast enough and cutting out power, the fault would present it seems when the car is on the move and it's trying to cut out power to slow down the car but the sensors see wheel rotation speed is not coming down, since you have a replacement one now you can plug also that one and check it, that would rule out any electrical problems while the car is stationary - now the other thing I have seen on the forums is the car might pass the self test when stationary BUT when it's on the move then things on the engine bay move around and people have had issues with engine mounts being knackered meaning that excessive movement was making cables or parts short, cable connectors momentarily lose contact, shorts against the bonnet or strut bars etc, see if that could be your case where under hard cornering or hard acceleration the ASC kicks in but at the same time something shorts due to engine or other parts moving around. The other thing that might be easier to check is the ASC relay - I guess that relay is not activated frequently and maybe the contacts inside are tarnished or there is something wrong - you can easily swap for another working good one.

 

[Sean d]

Been reading a bit about this out of curiosity - what I would do is - do the startup self check but with the throttle body connected but not attached to the intake boots so you can actually see if the butterfly actually moves, maybe the electrical connections are OK but somehow the butterfly is not moving or not moving fast enough and cutting out power, the fault would present it seems when the car is on the move and it's trying to cut out power to slow down the car but the sensors see wheel rotation speed is not coming down, since you have a replacement one now you can plug also that one and check it, that would rule out any electrical problems while the car is stationary - now the other thing I have seen on the forums is the car might pass the self test when stationary BUT when it's on the move then things on the engine bay move around and people have had issues with engine mounts being knackered meaning that excessive movement was making cables or parts short, cable connectors momentarily lose contact, shorts against the bonnet or strut bars etc, see if that could be your case where under hard cornering or hard acceleration the ASC kicks in but at the same time something shorts due to engine or other parts moving around. The other thing that might be easier to check is the ASC relay - I guess that relay is not activated frequently and maybe the contacts inside are tarnished or there is something wrong - you can easily swap for another working good one.

Thanks for that Mario, I'll give your ideas a try, really appreciate your help

 

[Jack Ratt]

Nice bit of research there @Mario

 

[Sean d]

Been reading a bit about this out of curiosity - what I would do is - do the startup self check but with the throttle body connected but not attached to the intake boots so you can actually see if the butterfly actually moves, maybe the electrical connections are OK but somehow the butterfly is not moving or not moving fast enough and cutting out power, the fault would present it seems when the car is on the move and it's trying to cut out power to slow down the car but the sensors see wheel rotation speed is not coming down, since you have a replacement one now you can plug also that one and check it, that would rule out any electrical problems while the car is stationary - now the other thing I have seen on the forums is the car might pass the self test when stationary BUT when it's on the move then things on the engine bay move around and people have had issues with engine mounts being knackered meaning that excessive movement was making cables or parts short, cable connectors momentarily lose contact, shorts against the bonnet or strut bars etc, see if that could be your case where under hard cornering or hard acceleration the ASC kicks in but at the same time something shorts due to engine or other parts moving around. The other thing that might be easier to check is the ASC relay - I guess that relay is not activated frequently and maybe the contacts inside are tarnished or there is something wrong - you can easily swap for another working good one.

Hi @Mario I checked the start up today and the throttle actuator does nothing at all but the asc and abs lights go out immediately, I disconnected it and put ignition on, both lights stay on, should it definately close the butterfly during start up, I also tried the other actuator with the same result

 

[Mario]

I will check on a car that I have here with ASC and let you know

 

[Neil Corfield]

I still have the ACS issues guys, the fault I am getting is code 50 throttle actuator, I swapped it today for a used one, took the car out and first bend I slid the rear and no light came on even though the wheels spun, gave it some beans on the straight and the rear stepped out, the light came on and didn't go out, it does reset itself with ignition, the butterfly feels nice and free,
Could this be related to the solder in the module, I beleive they are prone to breaking, @Antm72 did you have a similar issue
@Murray Wall any ideas pal

 

[Neil Corfield]

Good day,

ASC errors. If you have M52 engine then please check Vanos unit. This can cause issues with code 50.

Check misfires on HT, check leads and plugs.

Check for bad VSS sensor

Check obvious things tyres pressures and correct tyre fitment sizes. I.e. matched.

It would seem the ASC intervention has kicked in normally due to increase slip rate or perceived slip rate.

 

[Sean d]

Good day,

ASC errors. If you have M52 engine then please check Vanos unit. This can cause issues with code 50.

Check misfires on HT, check leads and plugs.

Check for bad VSS sensor

Check obvious things tyres pressures and correct tyre fitment sizes. I.e. matched.

It would seem the ASC intervention has kicked in normally due to increase slip rate or perceived slip rate.

Hi, thanks for the tips, the only code I am showing is code 50,
VSS ???

 

[Neil Corfield]

Hi, thanks for the tips, the only code I am showing is code 50,
VSS ???

Sorry VSS - Vehicle Speed Sensor.

 

[Sean d]

Sorry VSS - Vehicle Speed Sensor.

Is that the one on the diff, after I had removed the subframe I scanned the car and this came up as a problem, However the code cleared so I assumed it was stored due to being disconnected

 

[Neil Corfield]

Is that the one on the diff, after I had removed the subframe I scanned the car and this came up as a problem, However the code cleared so I assumed it was stored due to being disconnected

This is the most likely candidate for the VSS, If not fault currently exists then no worries. I think this is only for the speedometer on the Z3's.
Have you had a scope on the Wheel Speed sensors ?

1. Also does the fault only occur when Traction is lossed ( i.e wheel slip.) the traction light flashes then the fault appears ?
2. Does the throttle body have a single potentiometer or is it dual type ?
3. Is the throttle-body cable driven or Fly by wire ?
4. Does the Throttle Plates move now, when the ignition is switched on.

The expectation should be that if excessive slip is detected, then intervention will be applied. By what methods are deployed based on
the type of ABS,ASC+T, unit fitted.

Intervention will then in your case adjust the throttle response by means of plate adjustment either via cable or electric driven motors.
This parameter will be sent to the ECU via the Potentiometer to in some cases to both DME and ASC control units hence the reason for dual potentiometers on some systems. The plate adjustment will be activated and parameters sent, here comes the issue if the ECU does not see this response in correlation to the request then faults codes will appear. In other words if the ECU requested 5 Degrees of plate deflection ( a given voltage on the signal wire ) and the potentiometers do not relay the information back to the ECU's this suggest that is has not happened.

There are lots to check, but much easier with equipment. Scanners, Multimeters and Oscilliscope.

There are many things to check but if this were jumping the diagnostic timeline so to speak.
I would at some point check.

1. Ensure the ASC cable if fitted is correctly located and in the correct position. See step 2
2. With a a good scanner serial check monitored values of the potentiometer readings for both ASC and DME are reading the same.
3. Check Voltages and Grounds to the Potentiometers
4. Scope the signals on both ASC and DME
5. Check the ASC control unit to ensure that infact operational
6. Checking connection for all of the above.

Some systems would allow to calibrate the Potentiometers with pedal to floor 10 secs with ignition on, then switch of ignition and hold for approximately a further 10 secs.

I would as a precaution check the other stuff previously mentioned.

 

[Sean d]

• I'm pretty sure the fault only occurs when traction is lost

• I think the throttle body is single

• Throttle body has a cable that comes from an actuator

• No movement when ignition is switched on

 

[Neil Corfield]

I would expect the ASC control solenoids to carry out a check on ignition on.

On some you can open the cable window on the ASC solenoid. Check to see if cable is connected. Also perform same check to see if the gear moves with window open.

Next check the wiring. If you private send the VIN I will look at work for a wiring diagram, if I get 5 mins

 

[Sean d]

I would expect the ASC control solenoids to carry out a check on ignition on.

On some you can open the cable window on the ASC solenoid. Check to see if cable is connected. Also perform same check to see if the gear moves with window open.

Next check the wiring. If you private send the VIN I will look at work for a wiring diagram, if I get 5 mins

Thankyou for your help, the car recognises the actuator as when its disconnected the ASC and ABS lights stay on, I will make sure the cable is connected to the actuator, but seems a bit of a coincidence that two of them would have the same problem