Ground Diagram/key cycling/fuel pump

[MJinMB]

Hello, first time poster on this board. Nice place and lots of great info. 2002 Rio.

I’ve been trying to fix the key cycling no fuel pump problem. With info from this site and kiatechinfo.com I’ve managed to jump A and B on the diagnostic port and it seems that I’m only getting 10 volts at the fuel pump. So I’m hoping that this is a grounding issue. There are no other electrical problems at all just, fuel pump issue.

The info on the tech site states that there is a ground wire on the tank pressure sensor but I could not find. This sensor is grounded thru the plug. I could not find any info on the ground for the fuel pump if any. I believe that it is grounded thru the connector as well.

Should there be a separate ground from the pump body directly to the frame like I’ve been reading? My Rio does not have this.

Also on the kiatechinfo website there is a section called ETM and there are a 2 diagrams, one power wiring schematic and one ground schematic I can not get either one of these to load.

I’m wondering if there is any other place to find these diagrams. I would like to clean all the grounds and continue to troubleshoot this and these would be very helpful.

Thanks

[DIYrio]

You can pick up an Electrical Troubleshooting Manual that the Kia techs use for about $20-$25 USD on ebay. I got mine for $20 from Manualbasket, an ebay store for tach manuals and owners manuals (I sould have it in a few days). You can also try manuals4you, another ebay store. This is only necessary if you "geek out" on things, like me; or, if you are having trouble loading images off the tech site, like you.

[MJinMB]

To follow up on my post. I turns out that there are 3 different voltages in the fuel pump connection. The 10 volts I found was not for the fuel pump itself. I’m not sure what the 10 volts is for, I suspect some sort or return voltage to the computer.

I found the correct ground and power to the pump. After this I put switched power directly to the pump and attached it to the battery in a direct set up. Using the switch, cycled the pump on and off many times. The pump did not fail in this set up.

After this I cleaned all the grounds I could find and changed the fuel pump relay. I put everything back in it’s place and cycled the keys over fifty times and the pump started every time. My wife has been driving the car for 3 days now, going many places with no problems at all.

So although I didn’t do anything in a certain order, which I should have, I suspect it was the relay, even though it benched tested just fine. I can’t rule out the ground either because after cleaning the ground to the block the battery voltage went up from 12.12 to 12.44.

Thanks DIYrio for the manual sources.For now my problem is solved. I hope this post can help someone else out, as this forum did for me

[jcwit]

I've had 3 relays that tested OK but wouldn't work consistently. Replaced them with new ones and everything is alright. Go figure. BYW the only way I knew how to test was to check continuity.

[MJinMB]

Yep that’s the way I checked it too, the directions from the Kiatechinfo site.

I feel my(me and the brother-in-laws) way of directly putting power to the fuel pump would truly show if it failed under a power on power off situation, repeatedly. Cutting up some terminal ends so they just fit over the terminals in the fuel pump without touching is easily done. Before you send power to them just make sure they aren’t touching. You will also have to make sure you have a place to dump the fuel to when you pull the line off the fuel filter, also pretty simple.

Now I’ll say this my “ballparking” the correct terminals could have easily resulted in me frying the fuel sending unit because, I think, that was the circuit with only 3.5 volts. Although I didn’t send 12v’s to that one I did send 12v’s to the 10v I found which turned out to be incorrect, but all is well.

A tip I can offer is on a 2002 Rio if you look at the female connector straight on, you will have 3 spots at the top and 2 at the bottom. The 2 at the bottom should be a black(ground) and a red/white stripe(12v) this should not be less then .1 of a volt power drop between using these 2 connections then the voltage with a direct test to the battery. This info is found here Fuel pump diagnosis: Electrical tests | Motor | Find Articles at BNET please read this website carefully I found it to be very useful in my do-it-yourself fix for the problem I was having.

I have to say I found numerous posts about the same problem but not one posted if they had solved the problem or not. I own a jeep and posted every result to a question I have asked, as well as a ranger I owned. Being a “newbie” with only a few posts, many may not even read the post and I don’t blame them.

I’ve always said to myself that I will post my results, good or bad, so others can learn from what I have done and not just find a bunch of posts with their same problem and no answers on how to fix it.

I type with 2 fingers and this took me about 15-20 min so I hope it will help someone with the same problem down the road.

Cheers