Check engine light code 543 - what do i do?

[danmm7]

I got this code after a check engine light.

The manual says "Fuel pump secondary circuit fault".

Where do i start? What is causing this code?

I also got a 177 code. Not sure if it's related. Truck lost some power when the check engine light was ON. Felt like something was clogged. Then it ran fine again.



Thank you for any help!



1994 Mazda B4000, 2WD, M/T

 

[danmm7]

Is there a forum dedicated to check engine light codes & troubleshooting?

Thank you!

 

[bikerboy]

Sorry about the delay in help. Have you ever had it not start? It sounds like your fuel pump is going bad. Check for corrosion on your fuel pump relays, fuses, all fuel pump connections including the power and ground for the PCM. If they all check out ok then i would suspect fuel pump. Let us know how it works out for you too. Thanks!