luggy

I just picked up a 92 5.0 LX/notch and found that the check engine bulb was removed from the dash. It's now back and the check engine light stays on both in the key on position and when running. Checked codes and it reported:

KOEO: 63 - TPS circuit below minimum voltage
KOER: 63 - TPS circuit below minimum voltage &
98 - Hard Fault Present/FMEM Mode/Limp-in

1) Based on the code 63, I replaced the TPS and the voltage is reading 0.90 with the new tps (didn't check the old one), so that should be good.

2) I checked the wiring to the TPS, fixed a splice from a previous owner at the EGR/BP sensor (the orange/brown wire). Verified splice/tps wiring from a wiring diagram.

3) Did a code erase via the scan tool & reset the ecu by disconnecting the battery for a 1/2 hour (separate attempts).

4) Found that the car has a Jet Performance Chip, looked through their instructions and ended up cleaning the protective grease from the chip/ecu connector, tested with and without the chip installed.

It's still reporting the same error codes.

Anyone have an idea on what else I can check?

Can I safely test the TPS pinout at the ecu connector if I disconnect the computer (A9L)?

Any help is appreciated. Thanks!

luggy

Traced the voltage for the tps wire back to the ECU and found no voltage at the pin. Checked wiring and found a break. Spliced it back together and all is good now.

dreamer1uk

Nice job Did you check your TPS voltage at idle and WOT?

luggy

Yep. All within the allowable range. Put the original tps back in and works fine.