SL/R230: Hotline Archive: Suspension warning light is on with fault code C1525-064
Hotline Archive: Suspension warning light is on with fault code C1525-064
Having access to the biggest USA workshop live hotline databases, I will publish them here and might help some.
Customer Concern: Suspension warning light is on with fault code C1525-064.
Average Reported Mileage: 87367 Tests/Procedures:
1. With a factory compatible scan tool, monitor the hydraulic suspension pressure. System pressure should read around 180-200 bar.
2. If pressure is within specification, the fault is not current at this time. Check for correct fluid level and let car sit overnight to verify suspension does not leak down and cause car to drop to the ground.
3. Road test; if pressure falls low enough to set faults when going over large bumps, suspect failed front and or rear suspension accumulators. Accumulators will need to be removed for inspection. If a drift can be inserted into the opening of the accumulator, it has a ruptured diaphragm and will need to be replaced.
4. If pressure is not correct at idle, first verify correct fluid levels. Inspect system for external leaks. Test and inspect wiring at system pressure sensor for damage. There is no factory test for the sensor itself, replace sensor with known good component.
5. If pressures are still not correct, suspect faulty hydraulic suspension pump.
6. Replacement of any hydraulic component requires bleed function "Rodeo" with factory scan tool to remove all air from system. Replacement of strut due to external leakage requires calibration with factory scan tool. Tech Tips: This system requires a factory scan tool to help with diagnosis. C1525-064 System pressure too low. After repairs, you may need to apply pressure to the system reservoir and then open one bleeder screw at a time to prime the hydraulics before operation. Pressure return circuit has a pressure of 10 bar with engine running.
TOP Confirmed Fix cases:
cases/details
52 - Performed Hydraulic Suspension System Bleed Procedure
39 - Replaced/Resealed Active Body Control Pump
10 - Replaced Hydraulic Pump
7 - Replaced ABC Hydraulic High Pressure Line
6 - Replaced Hydraulic Suspension Pressure Hose
4 - Replaced Active Body Control (ABC) Suspension Strut
4 - Replaced Hydraulic Suspension Gas Chamber/Accumulator
4 - Adjusted Hydraulic Fluid Level
3 - Replaced Active Body Control Hydraulic Pressure Sensor
2 - Replaced Right Front (RF) Height Sensor
2 - Replaced Front Axle Valve Block Y36/1 and Replaced Rear Axle Valve Block Y36/2
2 - Replaced Rear Axle Valve Block Y36/2
1 - Replaced Hydraulic Hose and Replaced Hydraulic Pump
1 - Replaced Active Body Control (ABC) Suspension Strut and Replaced Active Body Control Pump and Performed Hydraulic Suspension System Bleed Procedure
1 - Replaced Hydraulic Pump and Performed Hydraulic Suspension System Bleed Procedure
1 - Replaced Front Axle Valve Block Y36/1
1 - Replaced Hydraulic Hose
1 - Replaced Active Body Control Hydraulic Pressure Sensor and Performed Hydraulic Suspension System Bleed Procedure
1 - Replaced Left Front Strut
1 - Replaced Fuse(s)
1 - Replaced Lower Ball Joint(s)
1 - Performed Hydraulic Suspension System Bleed Procedure and Replaced Tandem Pump
1 - Replaced ABC Hydraulic High Pressure Line and Replaced Active Body Control Pump and Performed Hydraulic Suspension System Bleed Procedure
1 - Performed Hydraulic Suspension System Bleed Procedure and Replaced Rear Axle Valve Block Y36/2
1 - Replaced Active Body Control Pump and Performed Hydraulic Suspension System Bleed Procedure
models concerned:
2003 SL500 5.0
2004 SL500 5.0
2005 SL500 5.0
2006 SL500 5.0
2005 SL55 AMG 5.5
2007 SL550 5.5
2005 SL600 5.5
Customer Concern: Suspension warning light is on with fault code C1525-064.
Average Reported Mileage: 87367 Tests/Procedures:
1. With a factory compatible scan tool, monitor the hydraulic suspension pressure. System pressure should read around 180-200 bar.
2. If pressure is within specification, the fault is not current at this time. Check for correct fluid level and let car sit overnight to verify suspension does not leak down and cause car to drop to the ground.
3. Road test; if pressure falls low enough to set faults when going over large bumps, suspect failed front and or rear suspension accumulators. Accumulators will need to be removed for inspection. If a drift can be inserted into the opening of the accumulator, it has a ruptured diaphragm and will need to be replaced.
4. If pressure is not correct at idle, first verify correct fluid levels. Inspect system for external leaks. Test and inspect wiring at system pressure sensor for damage. There is no factory test for the sensor itself, replace sensor with known good component.
5. If pressures are still not correct, suspect faulty hydraulic suspension pump.
6. Replacement of any hydraulic component requires bleed function "Rodeo" with factory scan tool to remove all air from system. Replacement of strut due to external leakage requires calibration with factory scan tool. Tech Tips: This system requires a factory scan tool to help with diagnosis. C1525-064 System pressure too low. After repairs, you may need to apply pressure to the system reservoir and then open one bleeder screw at a time to prime the hydraulics before operation. Pressure return circuit has a pressure of 10 bar with engine running.
TOP Confirmed Fix cases:
cases/details
52 - Performed Hydraulic Suspension System Bleed Procedure
39 - Replaced/Resealed Active Body Control Pump
10 - Replaced Hydraulic Pump
7 - Replaced ABC Hydraulic High Pressure Line
6 - Replaced Hydraulic Suspension Pressure Hose
4 - Replaced Active Body Control (ABC) Suspension Strut
4 - Replaced Hydraulic Suspension Gas Chamber/Accumulator
4 - Adjusted Hydraulic Fluid Level
3 - Replaced Active Body Control Hydraulic Pressure Sensor
2 - Replaced Right Front (RF) Height Sensor
2 - Replaced Front Axle Valve Block Y36/1 and Replaced Rear Axle Valve Block Y36/2
2 - Replaced Rear Axle Valve Block Y36/2
1 - Replaced Hydraulic Hose and Replaced Hydraulic Pump
1 - Replaced Active Body Control (ABC) Suspension Strut and Replaced Active Body Control Pump and Performed Hydraulic Suspension System Bleed Procedure
1 - Replaced Hydraulic Pump and Performed Hydraulic Suspension System Bleed Procedure
1 - Replaced Front Axle Valve Block Y36/1
1 - Replaced Hydraulic Hose
1 - Replaced Active Body Control Hydraulic Pressure Sensor and Performed Hydraulic Suspension System Bleed Procedure
1 - Replaced Left Front Strut
1 - Replaced Fuse(s)
1 - Replaced Lower Ball Joint(s)
1 - Performed Hydraulic Suspension System Bleed Procedure and Replaced Tandem Pump
1 - Replaced ABC Hydraulic High Pressure Line and Replaced Active Body Control Pump and Performed Hydraulic Suspension System Bleed Procedure
1 - Performed Hydraulic Suspension System Bleed Procedure and Replaced Rear Axle Valve Block Y36/2
1 - Replaced Active Body Control Pump and Performed Hydraulic Suspension System Bleed Procedure
models concerned:
2003 SL500 5.0
2004 SL500 5.0
2005 SL500 5.0
2006 SL500 5.0
2005 SL55 AMG 5.5
2007 SL550 5.5
2005 SL600 5.5
Last edited by pmercury; May 17, 2020 at 12:22 PM.
Banned
Joined: Jan 2006
Posts: 1,982
Likes: 393
From: Atlanta, unfortunately
'09 S600, (2) R129 300SLs, '03 SL500, '03 SL55
A few months ago I wrote on this forum that I would not trust a shop (of unknown repute) with a ABC repair. The prior post is evidence that my concerns are well-founded. A few comments.
An important part of the pressure supply is the throttle valve located at the inlet of the ABC pump. Before deciding to replace a pump the operation of that throttle should be checked with Star Diagnosis or by plugging/unplugging its electrical connector and watching for a change in system pressure.
There is a factory test for the pressure sensor. You check its output for plausibility with a diagnostic tool, check that it is powered by 5 VDC, and check that its signal voltage to the controller is 2-4 VDC.
If you remove the ABC reservoir return cap and observe that oil is returning to the pump at idle, then pressure at that moment is good regardless of any reading reported by the pressure sensor.
A momentary ABC warning which appears upon traversing a speed bump or similar road irregularity always indicates one or more failed accumulators. Rather than spend c. three hours removing each one and inspecting it for a defect it is far more efficient to simply allow Star Diagnosis to perform a one-minute test and report its findings.
An important part of the pressure supply is the throttle valve located at the inlet of the ABC pump. Before deciding to replace a pump the operation of that throttle should be checked with Star Diagnosis or by plugging/unplugging its electrical connector and watching for a change in system pressure.
There is a factory test for the pressure sensor. You check its output for plausibility with a diagnostic tool, check that it is powered by 5 VDC, and check that its signal voltage to the controller is 2-4 VDC.
If you remove the ABC reservoir return cap and observe that oil is returning to the pump at idle, then pressure at that moment is good regardless of any reading reported by the pressure sensor.
A momentary ABC warning which appears upon traversing a speed bump or similar road irregularity always indicates one or more failed accumulators. Rather than spend c. three hours removing each one and inspecting it for a defect it is far more efficient to simply allow Star Diagnosis to perform a one-minute test and report its findings.
