Need help ABC issue, tough one

Mar 21, 2014 | 12:42 AM

benz_addict

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From: Toronto

V12TT

Need help ABC issue, tough one

Need help you ABC experts out there.

Facts:
Pump producing 190 bar
Completes rodeo with no issues
Nice clean fluid
No visible leaks, maybe a moist hose at most

Problem:
ABC visit workshop.
STAR SDS Scan: ABC pressure sensor problem, and STAR said possible cause is the sensor itself. Weird. So I replaced pressure sensor B4/5. Took the car out for a hard drive. Light re-appeared. Re-scanned it. Same code, same problem. Just points to the pressure sensor once again.

When does it happen?
When I punch it off the lights, or downshift and punch it I get the red ABC VISIT WORKSHOP right away. Restart engine, then problem goes away.

My logic is leaning towards the accumulators. There's 3 I believe. One front left, one under the passenger seat, one in the rear.

Need your input.

Thanks!

Attached Thumbnails

Need help ABC issue, tough one-abc-pressure-sensor.jpg

Last edited by benz_addict; Mar 21, 2014 at 01:07 AM.

Mar 21, 2014 | 07:43 AM

mrbobby

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Joined: Aug 2010

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From: Kingsville Ontario (South of Detroit)

2003 S500 4Matic (SOLD) + 2004 S55 (SOLD) 2005 CLK 500 Cabriolet 2008 S 450

In the front part of the pump there is a black electrical sensor. This is probably the sensor referred to with your SDS scan. Unfortunately I'm told the sensor is not available other than with the purchase of a new pump.

This is the experience I just went through with my S55. For your sake, hopefully I'm wrong and was given bad info from my Indie but that's what recently cost me almost $2,000 to fix. Good luck with the repair.

Mar 21, 2014 | 05:58 PM

holycowe

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Could be the accumulators. But mine was lighted up everytime passing bumps or dips.
2 big ones, 1 in front of driver front wheel, 1 in the very back (lift car and you'll see it rightaway). The little one under pass. seat is a small one (pulsation damper).

Mar 22, 2014 | 10:12 PM

benz_addict

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From: Toronto

V12TT

Replaced front and rear accumulator. Also replaced the dampener. The dampener was squashed inside. Also replaced front level sensors as I got the code for them. I think my module may be going haywire since the problem still persists. White ABC visit workshop warning light appears after few minutes of driving. As soon as it appears I scan it and the same code appears. Actual value reads 255BAR (sign of a bad sensor) but after a restart cycle engine the sensor works fine again and shows 190BAR. Car rodeos fine with no pressure related codes. Any thoughts? Module? Bad wiring?

Mar 23, 2014 | 07:48 AM

mrbobby

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Joined: Aug 2010

Posts: 986

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From: Kingsville Ontario (South of Detroit)

2003 S500 4Matic (SOLD) + 2004 S55 (SOLD) 2005 CLK 500 Cabriolet 2008 S 450

PUMP

Mar 23, 2014 | 07:57 AM

mrbobby

Super Member

Joined: Aug 2010

Posts: 986

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From: Kingsville Ontario (South of Detroit)

2003 S500 4Matic (SOLD) + 2004 S55 (SOLD) 2005 CLK 500 Cabriolet 2008 S 450

Further to my "PUMP" reply, I have a pump on my garage that puts out a steady 190 to 200 bar and performs flawless rodeos but shows an SDS response of "pump pressure switch". The electrical connector at the pump is bad and not available as a replacement part. I bought a new pump and the problem is solved.

Mar 31, 2014 | 02:54 AM

benz_addict

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From: Toronto

V12TT

Quote:

Originally Posted by mrbobby

Thanks for the answers Bob. So you are suggesting the Y86/1 ABC suction restrictor valve which is located on the PUMP is causing the B4/5 pressure sensor issue? The sensor that star is pointing is under the passenger seat and not located on the pump. The Y86/1 ABC suction restrictor valve seems to be working fine with my diagnosis and the pump holds excellent pressure as during my numerous guided tests.

Here is the current standing of the car now:

Problem:
ABC White light comes on as soon as you go hard on the throttle. If you mash the throttle right down the white light turns to RED eventually. If you drive slow and steady the light does not come on. Even if I drive slow and go over a large pothole the light does not come on.

Codes:
When the WHITE light comes on the code generated is:
"C1148-001 Fault in component B4/5 (ABC pressure sensor)"
Under SDS ABC actual values the pump reads 255 BAR

Give it a restart then the light goes away and the pump reads steady 180-200 bar. I performed rodeo with no error codes generated and pressure holds steady.

When the RED light comes on the codes generated are:
"C1148-001 Fault in component B4/5 (ABC pressure sensor)"
"C1525-064 System pressure too low"
"C1133-004 FAULT IN COMPONENT B22/9 RIGHT FRONT LEVEL SENSOR"
"C1132-004 FAULT IN COMPONENT B22/8 LEFT FRONT LEVEL SENSOR"

Restart the car and all lights go away and the car is holding 180BAR right away????

SO I have replaced:
The actual pressure sensor underneath the passenger side on the pressure valve along with the dampener. I have replaced front and rear accumulators. I have replaced the front two strut level sensors. I have ran several rodeos.

Are there any ABC experts out there?