ABS, Traction control and Brake failure lights keeps on ! - Page 3

Mike · 3rd June 2007, 06:03

I would be checking the plenum areas for water. Your symptoms sounds like the ECU maybe getting an unwanted bath. If you haven't already then take a look here:

http://www.the75andztclub.co.uk/down...ile=tid002.pdf

http://www.the75andztclub.co.uk/down...ile=tid001.pdf

hth

Mike

JohnDotCom · 3rd June 2007, 09:30

There is an ABS sensor on Rear as well I'm pretty sure,
If it is disabled,The ABS light that is, over here, its an Automatic MOT Fail.

Yes the Rear ABS sensor ring is part of the Rear Hub Bearing assembly, and they are not cheap either.

Rover3088 · 4th June 2007, 09:55

I already clean up the plenum area when I replaced the pollen filter. However, I'm not sure whether the ECU itself had been unwanted bath before. If this is the case, how can recover the ECU ? replace a new one ? I hope not neccessary !

Moonstone · 4th June 2007, 15:34

Earlier posts hinted at checking the sensor wiring (not the sensors themselves) as these have been known to be damaged if not secured.

The fault codes you first posted come up on the BMW sites as related to a diagnostic facility to detect fuel leaks. I've never heard of such a thing on a 75 (yet). However, there must be fault codes somewhere that would give you a clue. Did the garage that replaced your sensors scan for fault codes, or did they just measure the sensor resistance?

One of the front sensors also supplies the speedometer, so if there'd been no signal from that, you wouldn't have had a speed reading.

The Modulator is not a cheap item. Maybe someone can confirm if it has its own ECU, separate to the engine one - that could also be at fault. Without a diagnostic, you (and the garage) are working in the dark. Will they refund the cost if a replacement doesn't fix the problem?

Rover3088 · 5th June 2007, 04:34

I've do ulmost to find a garage who have the specify diagnostic scanner for Rover (never find T4 here). Eventually I found a garage who have X431 with specify software for Rover 75 checking.

X431 told me that both front and rear ABS sensor and wiring are fine and working. However, a message (but Chinese only) displayed without code and it said "The relay of ABS malfunction". Therefore, I wondering if it problem from ABS Modulator as I can't find any separate relay on ABS system.

Since I purchased the front ABS sensor by myself directly from UK then give it to the garage to do the job. Cost is not so high but they will not refund even problem not fixed. I need them to do the job because they have X431 checking for me.

Anyway, really don't know what can do further. I'm afraid the problem still not fix even replaced the ABS modulator ! Any suggest would be much appreciated. Thanks !

Moonstone · 6th June 2007, 00:30

There may be relays controlling the solenoid valves. If so, they might be in the ECU attached to the modulator. That could be easier to repair than the modulator itself.

Rover3088 · 6th June 2007, 01:31

where is the relays controlling the solenoid valves ? Do you mean the wiring between the ECU and ABS modulator ? Thanks !

Moonstone · 8th June 2007, 08:32

I'm just guessing at their location, but the ECU seems a logical place for them to be. The unit is apparently a Bosch 5.7 ABS and the ECU is screwed onto the modulator housing, but it can be removed for repair - see this as an example:
http://cgi.ebay.com/ebaymotors/BMW-B...QQcmdZViewItem
or http://tinyurl.com/ypu2yn

Rover3088 · 8th June 2007, 09:25

Thanks !

But why the Bosch selling so cheap ? It just asking US$225only.

I found one on Ebay (A1 Automotive Ltd) cost GBP399.99

Moonstone · 12th June 2007, 12:17

I didn't read the page too closely, but it looks like a re-build service for the ECU only. The instructions say remove it from the modulator before sending.

Also, did you see the cost of postage! They must send someone to deliver it personally

3rd June 2007, 06:03	#21
Mike This is my second home Rover 75 V8 Join Date: Oct 2006 Posts: 3,448 Thanks: 0 Thanked 206 Times in 32 Posts	I would be checking the plenum areas for water. Your symptoms sounds like the ECU maybe getting an unwanted bath. If you haven't already then take a look here: http://www.the75andztclub.co.uk/down...ile=tid002.pdf http://www.the75andztclub.co.uk/down...ile=tid001.pdf hth Mike __________________ Mike [SIGPIC][/SIGPIC]

3rd June 2007, 09:30	#22
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	There is an ABS sensor on Rear as well I'm pretty sure, If it is disabled,The ABS light that is, over here, its an Automatic MOT Fail. Yes the Rear ABS sensor ring is part of the Rear Hub Bearing assembly, and they are not cheap either. Last edited by JohnDotCom; 3rd June 2007 at 09:35.. Reason: Update on rear abs sensor

4th June 2007, 09:55	#23
Rover3088 Regular poster Rover 75 Connoisseur Join Date: Apr 2007 Location: Hong Kong Posts: 84 Thanks: 0 Thanked 0 Times in 0 Posts	I already clean up the plenum area when I replaced the pollen filter. However, I'm not sure whether the ECU itself had been unwanted bath before. If this is the case, how can recover the ECU ? replace a new one ? I hope not neccessary ! __________________ [SIGPIC][/SIGPIC]Rover 75 HK owner

5th June 2007, 04:34	#25
Rover3088 Regular poster Rover 75 Connoisseur Join Date: Apr 2007 Location: Hong Kong Posts: 84 Thanks: 0 Thanked 0 Times in 0 Posts	I've do ulmost to find a garage who have the specify diagnostic scanner for Rover (never find T4 here). Eventually I found a garage who have X431 with specify software for Rover 75 checking. X431 told me that both front and rear ABS sensor and wiring are fine and working. However, a message (but Chinese only) displayed without code and it said "The relay of ABS malfunction". Therefore, I wondering if it problem from ABS Modulator as I can't find any separate relay on ABS system. Since I purchased the front ABS sensor by myself directly from UK then give it to the garage to do the job. Cost is not so high but they will not refund even problem not fixed. I need them to do the job because they have X431 checking for me. Anyway, really don't know what can do further. I'm afraid the problem still not fix even replaced the ABS modulator ! Any suggest would be much appreciated. Thanks ! __________________ [SIGPIC][/SIGPIC]Rover 75 HK owner

6th June 2007, 01:31	#27
Rover3088 Regular poster Rover 75 Connoisseur Join Date: Apr 2007 Location: Hong Kong Posts: 84 Thanks: 0 Thanked 0 Times in 0 Posts	where is the relays controlling the solenoid valves ? Do you mean the wiring between the ECU and ABS modulator ? Thanks ! __________________ [SIGPIC][/SIGPIC]Rover 75 HK owner

4th June 2007, 15:34	#24
Moonstone Loves to post Rover 75 Tourer Join Date: Nov 2006 Location: Scotland Posts: 412 Thanks: 0 Thanked 1 Time in 1 Post	Earlier posts hinted at checking the sensor wiring (not the sensors themselves) as these have been known to be damaged if not secured. The fault codes you first posted come up on the BMW sites as related to a diagnostic facility to detect fuel leaks. I've never heard of such a thing on a 75 (yet). However, there must be fault codes somewhere that would give you a clue. Did the garage that replaced your sensors scan for fault codes, or did they just measure the sensor resistance? One of the front sensors also supplies the speedometer, so if there'd been no signal from that, you wouldn't have had a speed reading. The Modulator is not a cheap item. Maybe someone can confirm if it has its own ECU, separate to the engine one - that could also be at fault. Without a diagnostic, you (and the garage) are working in the dark. Will they refund the cost if a replacement doesn't fix the problem?

6th June 2007, 00:30	#26
Moonstone Loves to post Rover 75 Tourer Join Date: Nov 2006 Location: Scotland Posts: 412 Thanks: 0 Thanked 1 Time in 1 Post	There may be relays controlling the solenoid valves. If so, they might be in the ECU attached to the modulator. That could be easier to repair than the modulator itself.

8th June 2007, 08:32	#28
Moonstone Loves to post Rover 75 Tourer Join Date: Nov 2006 Location: Scotland Posts: 412 Thanks: 0 Thanked 1 Time in 1 Post	I'm just guessing at their location, but the ECU seems a logical place for them to be. The unit is apparently a Bosch 5.7 ABS and the ECU is screwed onto the modulator housing, but it can be removed for repair - see this as an example: http://cgi.ebay.com/ebaymotors/BMW-B...QQcmdZViewItem or http://tinyurl.com/ypu2yn

8th June 2007, 09:25	#29
Rover3088 Regular poster Rover 75 Connoisseur Join Date: Apr 2007 Location: Hong Kong Posts: 84 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks ! But why the Bosch selling so cheap ? It just asking US$225only. I found one on Ebay (A1 Automotive Ltd) cost GBP399.99 __________________ [SIGPIC][/SIGPIC]Rover 75 HK owner

12th June 2007, 12:17	#30
Moonstone Loves to post Rover 75 Tourer Join Date: Nov 2006 Location: Scotland Posts: 412 Thanks: 0 Thanked 1 Time in 1 Post	I didn't read the page too closely, but it looks like a re-build service for the ECU only. The instructions say remove it from the modulator before sending. Also, did you see the cost of postage! They must send someone to deliver it personally