ABS Light on...could this be the reason? - Page 2

drjonts · 29th October 2020, 11:23

...and that's an MOT pass!

Everything was spot on mechanically, and the brakes were great...even with a strong and well-balanced handbrake result!

Couple of advisory points - rear arms / suspension components are getting crusty. Looks like the time is here to clean the back end up and get some rustproofing / coating work done. Maybe I'll fit that new rear anti-roll bar and links I bought ages back...and then perhaps fit the rear backplates I got from Mat while I'm in there. Do I just get some rear arms on order and do a whole load of jobs I wonder?

Anyhooo...happy days!

Jonty

StewartIngram · 11th May 2024, 13:28

Old thread I know, but I have a question if anyone is looking?

I note the problems mentioned - o/s/f sensors (no speedo), n/s/f sensor (cruise control), associated abs faults, etc, but one thing puzzles me, the fuel gauge fault. What are the symptoms here? I run on lpg so rarely use petrol except when starting, I've never noticed a gauge problem.
At the present time, I've just gone through the (intermittent) abs light (and with it the red brake fault light), and speedo not working. Used to come ok with restarting the engine, now it seems to be a solid fault. I checked the o/s/f sensor blue plug, which fell apart as I tried to separate it; a squirt of switch cleaner on the pins did cure it but it since failed again. I've cut the plug off and soldered the connections so that is now eliminated. Wheel bearing seems clean and solid, so I'm leaning towards the abs modulator/connector.
I had this on a previous car; as mentioned above, trying to clean it broke some pins, so a s/h replacement was done similar to the above post. This was years ago and f've forgotten the " how-to" of it!. What is the best access to the connector? How does it come apart? I have memories of plastic clips etc which might break (happens in lots of connectors around the car).
I should have spares available in the shed off previous cars I've stripped so hopefully I can do it ok, but can anyone provide a "how-to"?

bearhouse · 12th May 2024, 05:38

Hi Johnty,

What a fantastic job. I tried to separate the two parts of the ABS pump while still connected to the brake pipes but as hard as I tried and couldn't get to all six torq screws. I could get to the three on the left and the top right but not the other two. I managed to cut and bruise both hands and arms and finally had to give up!

Tomorrow, I'm having someone replace my pump and bleed the brakes. Like you, my ABS light and handbrake light are constantly on. I had corrosion in the connector and when I tried to clean a couple of pins broke off as they were rotten. When I get the pump out, I'll open to see if anything like yours inside.

I would be grateful if someone could tell me how to add photos to a post and I can't seem to see how to do it.

Fingers crossed all works as the MOT's due!

Regards,

Terry.

StewartIngram · 12th May 2024, 13:11

Good news and not so good news.
Started the car this morning, everything ok again, but the fault came back after a short while. Same thing happened on the return journey.
Having doubled checked that i wired the sensor on the o/s/f (removing the blue connector), I'm down to the ABS modulator area. Hopefully the connector, but a bit of a pain to access.
I found my spare off one of the old cars in the shed this morning, which enabled me to see how the connector comes off, and also remove the electrics side of the modulator. So thats the good news.
Bad news (maybe). As I removed the electrics, one of the coils remained on its armature and that pulled the wiring out. So I'm not starting the job until I get a spare base (just in case).
The connector, it was one I replaced years ago (along with the electrics base if I remember correctly). I crimped the wires onto the car loom about 6" along the loom, a little tedious but very do-able.
Now, does anyone have a spare electrical abs base or complete unit going spare please?

bearhouse · 13th May 2024, 06:15

If you have traction control, the 'ML' pumps are difficult to find now. I just bought one from Poland, being fitted today.

Like you, I have an ABS fault which has now developed into a Brake Fault. Did your ABS repair cure both faults albeit temporarily? Otherwise, what was the cause of the brake fault?

The ABS pumps obviously suffer from water ingress. How you figured out where the water comes from?

I want to avoid the issue happening again in the future.

Regards,

Terry.

StewartIngram · 13th May 2024, 07:20

Firstly, I don't have traction control.
Secondly, On the present car I've yet to find the fault. From past history (I've had R75s since 2007, always done all my own maintenance), I'm now almost certain it is a fault with the ABS modulator or connector. Due to access to it, I haven't yet looked at it. However, I kept the old modulator from the last car when I stripped it. The connector on that looks perfect. I've seen 3 or 4 with water ingress but I don't know how it got in.
Thinking I might need to change the ecu on the modulator, I removed it from the spare, but it is broken. I am therefore looking for a replacement.
Stewart

Mike Noc · 13th May 2024, 08:31

Stewart have you fully tested the wiring, ABS sensors and magnetic reluctors on all the wheels? If not then certainly worth doing before you suspect the modulator, and easy enough to do with just a multimeter.
If you are using the poke and hope method then it is very easy to add faults to the system when working on it.

SD1too · 13th May 2024, 10:09

Quote:

Originally Posted by StewartIngram

At the present time, I've just gone through the (intermittent) abs light (and with it the red brake fault light) ... now it seems to be a solid fault.

If this is still the case Stewart, that you have ABS and Brake warning lamps continuously illuminated, then RAVE defines this as an ABS and EBD (Electronic Brake Distribution) fault.
EBD is performed by the ABS modulator but as Mike says, it needs to receive valid signals to work properly.

Simon

StewartIngram · 14th May 2024, 07:10

Yes been through all that and with previous experience of the fault on another car.
Due to the need to get a spare, I've ordered a s/h replacement ABS modulator from Germany, due here on Thursday. I then will gain access to the one on the car with the knowledge of having a spare at hand to save stripping things apart again.

29th October 2020, 11:23	#11
drjonts Loves to post MG ZT-T 160 Join Date: Dec 2015 Location: Devon Posts: 288 Thanks: 179 Thanked 70 Times in 53 Posts	...and that's an MOT pass! Everything was spot on mechanically, and the brakes were great...even with a strong and well-balanced handbrake result! Couple of advisory points - rear arms / suspension components are getting crusty. Looks like the time is here to clean the back end up and get some rustproofing / coating work done. Maybe I'll fit that new rear anti-roll bar and links I bought ages back...and then perhaps fit the rear backplates I got from Mat while I'm in there. Do I just get some rear arms on order and do a whole load of jobs I wonder? Anyhooo...happy days! Jonty Last edited by drjonts; 29th October 2020 at 11:48..

11th May 2024, 13:28	#12
StewartIngram Gets stuck in Rover 75 Connoisseur 2.5 V6 auto Join Date: Jan 2008 Location: Chatteris, Cambridgeshire Posts: 917 Thanks: 320 Thanked 159 Times in 127 Posts	Old thread I know, but I have a question if anyone is looking? I note the problems mentioned - o/s/f sensors (no speedo), n/s/f sensor (cruise control), associated abs faults, etc, but one thing puzzles me, the fuel gauge fault. What are the symptoms here? I run on lpg so rarely use petrol except when starting, I've never noticed a gauge problem. At the present time, I've just gone through the (intermittent) abs light (and with it the red brake fault light), and speedo not working. Used to come ok with restarting the engine, now it seems to be a solid fault. I checked the o/s/f sensor blue plug, which fell apart as I tried to separate it; a squirt of switch cleaner on the pins did cure it but it since failed again. I've cut the plug off and soldered the connections so that is now eliminated. Wheel bearing seems clean and solid, so I'm leaning towards the abs modulator/connector. I had this on a previous car; as mentioned above, trying to clean it broke some pins, so a s/h replacement was done similar to the above post. This was years ago and f've forgotten the " how-to" of it!. What is the best access to the connector? How does it come apart? I have memories of plastic clips etc which might break (happens in lots of connectors around the car). I should have spares available in the shed off previous cars I've stripped so hopefully I can do it ok, but can anyone provide a "how-to"?

12th May 2024, 05:38	#13
bearhouse Avid contributor Rover 75 Join Date: Aug 2009 Location: Herts Posts: 114 Thanks: 0 Thanked 0 Times in 0 Posts	Hi Johnty, What a fantastic job. I tried to separate the two parts of the ABS pump while still connected to the brake pipes but as hard as I tried and couldn't get to all six torq screws. I could get to the three on the left and the top right but not the other two. I managed to cut and bruise both hands and arms and finally had to give up! Tomorrow, I'm having someone replace my pump and bleed the brakes. Like you, my ABS light and handbrake light are constantly on. I had corrosion in the connector and when I tried to clean a couple of pins broke off as they were rotten. When I get the pump out, I'll open to see if anything like yours inside. I would be grateful if someone could tell me how to add photos to a post and I can't seem to see how to do it. Fingers crossed all works as the MOT's due! Regards, Terry.

12th May 2024, 13:11	#14
StewartIngram Gets stuck in Rover 75 Connoisseur 2.5 V6 auto Join Date: Jan 2008 Location: Chatteris, Cambridgeshire Posts: 917 Thanks: 320 Thanked 159 Times in 127 Posts	Good news and not so good news. Started the car this morning, everything ok again, but the fault came back after a short while. Same thing happened on the return journey. Having doubled checked that i wired the sensor on the o/s/f (removing the blue connector), I'm down to the ABS modulator area. Hopefully the connector, but a bit of a pain to access. I found my spare off one of the old cars in the shed this morning, which enabled me to see how the connector comes off, and also remove the electrics side of the modulator. So thats the good news. Bad news (maybe). As I removed the electrics, one of the coils remained on its armature and that pulled the wiring out. So I'm not starting the job until I get a spare base (just in case). The connector, it was one I replaced years ago (along with the electrics base if I remember correctly). I crimped the wires onto the car loom about 6" along the loom, a little tedious but very do-able. Now, does anyone have a spare electrical abs base or complete unit going spare please?

13th May 2024, 06:15	#15
bearhouse Avid contributor Rover 75 Join Date: Aug 2009 Location: Herts Posts: 114 Thanks: 0 Thanked 0 Times in 0 Posts	If you have traction control, the 'ML' pumps are difficult to find now. I just bought one from Poland, being fitted today. Like you, I have an ABS fault which has now developed into a Brake Fault. Did your ABS repair cure both faults albeit temporarily? Otherwise, what was the cause of the brake fault? The ABS pumps obviously suffer from water ingress. How you figured out where the water comes from? I want to avoid the issue happening again in the future. Regards, Terry.

13th May 2024, 07:20	#16
StewartIngram Gets stuck in Rover 75 Connoisseur 2.5 V6 auto Join Date: Jan 2008 Location: Chatteris, Cambridgeshire Posts: 917 Thanks: 320 Thanked 159 Times in 127 Posts	Firstly, I don't have traction control. Secondly, On the present car I've yet to find the fault. From past history (I've had R75s since 2007, always done all my own maintenance), I'm now almost certain it is a fault with the ABS modulator or connector. Due to access to it, I haven't yet looked at it. However, I kept the old modulator from the last car when I stripped it. The connector on that looks perfect. I've seen 3 or 4 with water ingress but I don't know how it got in. Thinking I might need to change the ecu on the modulator, I removed it from the spare, but it is broken. I am therefore looking for a replacement. Stewart

13th May 2024, 08:31	#17
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,571 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Stewart have you fully tested the wiring, ABS sensors and magnetic reluctors on all the wheels? If not then certainly worth doing before you suspect the modulator, and easy enough to do with just a multimeter. If you are using the poke and hope method then it is very easy to add faults to the system when working on it.

14th May 2024, 07:10	#19
StewartIngram Gets stuck in Rover 75 Connoisseur 2.5 V6 auto Join Date: Jan 2008 Location: Chatteris, Cambridgeshire Posts: 917 Thanks: 320 Thanked 159 Times in 127 Posts	Yes been through all that and with previous experience of the fault on another car. Due to the need to get a spare, I've ordered a s/h replacement ABS modulator from Germany, due here on Thursday. I then will gain access to the one on the car with the knowledge of having a spare at hand to save stripping things apart again.