Alright, Pulling codes on my 95 F-150 tonight cuz the check engine light is on, I got the TP sensor voltage lower than expected, I also got code 989, though it may have been 998, hard fault in FMEM, I have never seen this code before, does anyone have any insight as to why/what it is?

Thanks.

Joe.

 

I also have a 95 and my information says there is no 999, so it must be a 998.

Code 998 is indeed for FMEM which stands for Failure Mode Effects Management. As I understand it, this basically means you need to address any other codes and run the test again, for some reason the self test didn't read correctly but there is no specific error mentioned.

 

As Clifford mentioned, 998 means the the computer is in FFEM mode. It also means you have to got to address the Continuous code(s) that were displayed.

While in FFEM, the PCM cannot execute major portions of the PCM KOER self-test. That's why you need to fix the cause of the continuous codes first.

The mentioned TPS code could be the sensor, the TPS connector/harness, or even the PCM. Further diagnosis is suggested to pinpoint the fault.

Steve