Trouble code 528 - - need more info than currently on forum

[Randall]

Hey Guys!

I did an extensive search for code 528 on this forum, and even searched for Steve's (ProjectSHO89) responses as these usually allow me to avoid making a thread, but with this particular code, I am getting nothing.

I have had this code along with a code 219 for a few weeks, and from experience I know 219 usually means the DIS is bad, which I saw yet again as I changed the DIS a few days ago and 219 is no where to be found now when I run the codes, but that stubborn 528 is still there. I know that this code is for a clutch switch, but does that mean AC clutch switch or clutch pedal switch? Either way, I have been getting 17mpg lately although I have not filled up and recalculated since changing the DIS a few days ago that may have been causing the drop in fuel economy. But, I wanted to see if 528 has anything to do with fuel calibrations or even just the running conditions of a SHO engine? I looked in my repair manual, and it defines 528 as a "PNP short or low voltage at pin 30" which makes no sense to me since the booklet that came with my code reader says it is a clutch switch issue.

Anyway, any help here would be great as I went almost an entire year without a single code, and would like to go back to that status!

Thanks!

 

[n8rsk8r]

clutch switch circuit failure? that is what I come up with the code 528 did you come up with also? Pins 46 & 30 are what goes to the CES (Clutch Engagement Switch) 46 is signal return and the 30 is the input power to switch. so... is it the wiring harness issue? FWIW it is a "continuous code" try to erase them and see if it comes back

 

[projectSHO89]

Clutch pedal, not the A/C clutch.

For the 92 SHO, DTC 528 indicates that the PCM detected that pin 30 CES (Clutch Engagement Switch) was high (not grounded) during a cranking episode.

In normal operation, the CES is closed and pin 30 is grounded (low) whenever the clutch pedal is pressed. Do not depress the clutch pedal while running KOEO PCM Quick Test.

You can pull the connector from the PCM and measure between pins 30 and 46 with an ohmmeter. Should be an open circuit. Press the clutch pedal and it should go to a closed circuit. Check the pin 20 side for possible shorts to power or ground. If all checks are normal, the PCM is likely defective.

Primary use of the CES signal is to 1) Disengage the cruise and 2) Signal the PCM to control idle speed and for dashpot control.

Steve

 

[Randall]

thanks N8rsk8r, I did reset the the codes a few times and it seems to always be there when I check them again. I think your idea about the wiring may be dead on!

Thanks Steve, you are awesome, as always! Now I know exactly what to check and how to do it. You are a great asset to this forum! I noticed my SHO does seem to take a few seconds to come back down to idle after slowing to a stop on occasion, so hopefully it is just the switch going bad. thanks again!

 

[projectSHO89]

That condition is relatively normal on an MTX.