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Roy
Roy, import/domestic specialest
Category: Hyundai
Satisfied Customers: 6049
Experience:  ASE master tech for 40 years
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I am having this same issue with a 2006 hyundai santa fe

Customer Question

I am having this same issue with a 2006 hyundai santa fe 2.7l. Intermittently stays running with the ignition off. First I had rich fuel trim readings and the upstream o2 sensors were not fluctuating. Replaced the MAF and that fixed that problem. I tested the ignition switch by removing the ignition fuse when the symptom occurs and the engine just stays running. Im stumped.
Submitted: 9 months ago.
Category: Hyundai
Expert:  Roy replied 9 months ago.

hello, my name is ***** ***** I will be glad to assist you. please allow me a couple of minutes to gather some basic info.

Roy

Expert:  Roy replied 9 months ago.

ok, there is an engine control relay in the underhood fuse block. if that relay sticks, it will send a continuous signal to the pcm that the ignition switch is on and the engine needs to run.

try removing the relay to see if it shuts off.

Roy

Customer: replied 9 months ago.
It does shut off when I remove that relat.
Customer: replied 9 months ago.
Relay
Expert:  Roy replied 9 months ago.

ok, first. I would replace that relay and see if that resolves it. if not, then we need to look at the control side controls.

the relay should be available at a parts store and they are cheap to buy.

Roy

Customer: replied 9 months ago.
Ok. I will try that first. Thanks.
Expert:  Roy replied 9 months ago.

your welcome

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Expert:  Roy replied 9 months ago.

are you there

Customer: replied 9 months ago.
Im here. I can't get the part till tomorrow and Hyundai was the only one that could get it. I will let you know tomorrow.
Expert:  Roy replied 9 months ago.

ok

Customer: replied 9 months ago.
The relay did not fix. Seems to happen mostly when the engine is really warmed up and after reving up the engine a couple of times.
Expert:  Roy replied 9 months ago.

ok, when you pull the relay and it shuts off, does the relay click???

Expert:  Roy replied 9 months ago.

are you there

Customer: replied 9 months ago.
Just finally jad a chance to check that. I did not feel a click no.
Expert:  Roy replied 9 months ago.

do you have an ohm meter to check some wiring???

Customer: replied 9 months ago.
Expert:  Roy replied 9 months ago.

I am wondering here. removing the relay, no click concerns me that there may be a wiring issue.

the relay controls the fuel pump and feeds the pcm. wondering if the pcm is getting voltage it should not get.

also wondering about the ignition switch not cutting voltage as well. if you play with the key, will it shut off??

Customer: replied 9 months ago.
No. But if I tap the gas pedal it will.
Expert:  Roy replied 9 months ago.

thats not good.

either you have a wiring harness issue or a pcm that is internally shorted

let me look further at the wire diagrams

Customer: replied 9 months ago.
I pulled the pcm and took it apart. There were no burn marks or corosion. Nor did it smell burnt.
Customer: replied 9 months ago.
I am working on like 3 cars right now so please be patient with my responses.
Expert:  Roy replied 9 months ago.

you dont need to see it or smell it. it could be as simple as a bad diode.

Roy

Customer: replied 9 months ago.
Gotcha. How can I test that?
Expert:  Roy replied 9 months ago.

thats something that we as techs cannot check. you need special equipment for that. a parts store can send it out to a rebuilder who will check it and confirm if it is good or bad

Roy

Customer: replied 9 months ago.
thats it, huh? Thats all it could be?
Expert:  Roy replied 9 months ago.

I am here and not there. I cannot see it touch it or diag. I rely on your input. we give advice based on your input and our expierence.

as I stated before, either a wiring issue or pcm issue. both of these need to be checked.