Blinking Diagnostic Warning Lamp - 1979 928
Posted: Wed Feb 19, 2025 9:42 pm
The master warning is there for a reason … if it screams!!! Even more of a reason. On my 1979 just blinking like crazy and wouldn’t cancel out. I thought it was broken.
I was on my knees this morning working to remove that pesky diagnostic warning controller, I didn’t see a reason for it to be flashing therefore it must have failed.
While I was on my knees preparing to remove the diagnostic module, what did I see but brake fluid leaking from the clutch master cylinder. I then check the brake fluid reservoir and yes, it was more than ½ low. Once filled, the master warning was silent.
So, a 46 year old diagnostic system is working and doing a great job!! That is if trusted. Yet another lesson learned … check EVERYTHING before doubting that warning system.
Next, the dreaded clutch master cylinder replace. Ugh.
Rich
928 OC Membership Chairman
1993 928 GTS Cover Girl
1987 928 S4
1979 928 5-speed rescue
1979 928 Euro 5-liter track beast
I was on my knees this morning working to remove that pesky diagnostic warning controller, I didn’t see a reason for it to be flashing therefore it must have failed.
While I was on my knees preparing to remove the diagnostic module, what did I see but brake fluid leaking from the clutch master cylinder. I then check the brake fluid reservoir and yes, it was more than ½ low. Once filled, the master warning was silent.
So, a 46 year old diagnostic system is working and doing a great job!! That is if trusted. Yet another lesson learned … check EVERYTHING before doubting that warning system.
Next, the dreaded clutch master cylinder replace. Ugh.
Rich
928 OC Membership Chairman
1993 928 GTS Cover Girl
1987 928 S4
1979 928 5-speed rescue
1979 928 Euro 5-liter track beast