Replaced PS/ACE Reservoir Now Yellow Ace Light On
I meant to post this in the D2 thread, could a moderator move or delete this post?
I have a 99 D2 Equipped with ACE that I tried to fix one problem but seemingly have caused another. Since buying the car earlier this year the ACE system has worked flawlessly minus pretty constant leaks where the hoses meet the reservoir. So I finally got around to replacing the hoses that leaked the worst along with the reservoir itself. Everything seemed to go smoothly except now 30s after starting the car I get the amber ACE light which sets code 20-04 Pressure Control Valve Fault. I attempted to bleed the system with my nanocom as I figured there could be an air bubble trapped in the system but that did not correct the issue. I had done some research on the forums where people recommended running generic synthetic power steering fluid as it helped quiet the pump but I'm wondering if this fluid I used may be thicker than the original fluid, causing the pressure to exceed the approved values of the system? If the issue persists I will probably swap the fluid again to the proper ACE fluid to see if it will correct the issue but wondered if anyone else had experienced something similar?
I have a 99 D2 Equipped with ACE that I tried to fix one problem but seemingly have caused another. Since buying the car earlier this year the ACE system has worked flawlessly minus pretty constant leaks where the hoses meet the reservoir. So I finally got around to replacing the hoses that leaked the worst along with the reservoir itself. Everything seemed to go smoothly except now 30s after starting the car I get the amber ACE light which sets code 20-04 Pressure Control Valve Fault. I attempted to bleed the system with my nanocom as I figured there could be an air bubble trapped in the system but that did not correct the issue. I had done some research on the forums where people recommended running generic synthetic power steering fluid as it helped quiet the pump but I'm wondering if this fluid I used may be thicker than the original fluid, causing the pressure to exceed the approved values of the system? If the issue persists I will probably swap the fluid again to the proper ACE fluid to see if it will correct the issue but wondered if anyone else had experienced something similar?
Last edited by RossN99; Nov 24, 2025 at 11:21 PM.
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