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sprinkles08
sprinkles08, ASE Certified Technician
Category: Kia
Satisfied Customers: 21602
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
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2002 sedonna, v6, engine temp gauge pegs past hot with no

Customer Question

2002 sedonna, v6, engine temp gauge pegs past hot with no overheat symptoms. new t-stat & temp sending unit. rad sys holds 23 psi of pressure. sending unit plug has 4v on one pin, 10 volts on the middle pin. ground out 10v pin and temp gauge pegs hot, remove ground and gauge needle goes full cold
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Customer: kia
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Customer: kia sedona
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Customer: yes
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Submitted: 6 months ago.
Category: Kia
Expert:  Andrew Martin replied 6 months ago.

If you are measuring at the coolant temperature sensor connector, the black and yellow wire should have continuity to ground. The blue and yellow wire should have 0V. If either of those two do not match the specification then there is a wiring issue. The orange wire is the wire that goes to the instrument cluster for the temp gauge. If you can check for a short to power with the connector disconnected and the key on, you should not have voltage at the orange wire. If you do, then you have a short to power somewhere in that harness. If all of that is ok, it is likely that the gauge cluster is the issue, since you have already replaced the coolant temperature sensor.

If my answer has helped you, please help me by rating or accepting my answer. This does not cost you any more, it just allows me to be credited for my work. You can always ask follow up questions after rating or accepting. Thank you.

Customer: replied 6 months ago.
is blue and yellow wire to feedback to ECM? if so, plz give me pin out at ecm harness so I can ohm it out. I ohm pins 1 & 3 on the temp sensor and @ 84 degrees in got 1.4 ohms. The middle pin ohms out to the body of the sensor. With key ON, you're saying orange (middle) wire should have 0 Volts?! a related problem is this vehicle's AC system will not work either. I believe its because the ECM thinks the engine is running hot and will not allow the compressor to engage. I will check the wires tomorrow and get back with you.
Customer: replied 6 months ago.
can you send me a pic of the harness routing for this sensor? also, do you know of common solutions with this issue that I can jump to? i.e., wire splice corroded at ??
Expert:  Andrew Martin replied 6 months ago.

The blue and yellow wire is signal from the ECM, the orange wire is signal from the temp sensor to the gauge cluster. The black and yellow wire is sensor ground coming from the ECM. With the sensor connector UNHOOKED you should have 0V at the orange wire on the connector. Checking resistance is only going to tell you whether the sensor is working properly not if there is a short to power somewhere in the harness. I'll send you the diagrams. If it is a wiring issue you could run a wire from the gauge cluster to the connector yes.

Customer: replied 6 months ago.
Key on & connector off, LY wire 4.6v, O wire 9.6v, BY wire ohms to ground. With key OFF; LY wire 0v, O wire & BY wires both ohm to ground. So, I'm getting stray voltage to the orange wire that should be sending volts to the gauge from the #2 pin of the sensor. I need a picture of the wire harness routing of that circuit. Also, is it possible that the cluster could be the problem and have a short to power that is causing the O wire to carry the 9.6v?
Customer: replied 6 months ago.
this seems incorrect to me...temp gauges usually send voltage to the sensor and the bimetallic strips vary ground resistance thus changing needle position. Are you sure the sensor actually SENDS voltage to the gauge?
Customer: replied 6 months ago.
I'm not going to rate anyone's answers until this is resolved. I'm still troubleshooting this issue...
Customer: replied 6 months ago.
i've removed the instrument cluster and disconnected the 3 harness connectors. Which wire goes to the temp gauge from the orange wire on the sensor connector so I can ohm it.
Expert:  sprinkles08 replied 6 months ago.

Hello and welcome to JustAnswer!

Do you still need help?

Customer: replied 6 months ago.
Customer: replied 6 months ago.
previous tech left the discussion before we solved my problem...
Expert:  sprinkles08 replied 6 months ago.

The first step in diagnosing the issue is to use a scan tool or code reader to first record and clear codes from the powertrain control module, start the engine and see if any codes reset. Can you do this?

Customer: replied 6 months ago.
there are no codes present
Expert:  sprinkles08 replied 6 months ago.

After a cold soak have you compared intake, coolant and ambient temperature?

Customer: replied 6 months ago.
no. whats the purpose in this?
Expert:  sprinkles08 replied 6 months ago.

Checking the coolant sensor signal accuracy. It's the first step in diagnosing the problem if there are no fault codes set.

Customer: replied 6 months ago.
how is this accomplished?
Expert:  sprinkles08 replied 6 months ago.

With a scan tool.

Customer: replied 6 months ago.
what am i looking for under these parameters?
Expert:  sprinkles08 replied 6 months ago.

You're looking at the signals from these temperature sensors to see whether they agree.

Customer: replied 6 months ago.
ok, I'll look at the temps on those sensors
Expert:  sprinkles08 replied 6 months ago.

Ok.

Customer: replied 6 months ago.
i was incorrect about the codes...the CEL wasn't on but I pulled a p0118 code. I'm not sure if this set bc I've been disconnecting the plug and troubleshooting though.
Customer: replied 6 months ago.
also got p0431, p0160, p0446, p0500. these are all O2 sensor related. I noticed in the schematic for the ect sensor that terminal 3 is connected to the 02 sensors circuit section b1-e (circle 11)
Customer: replied 6 months ago.
446 are vent system and 500 is speed sensor...not o2 related
Expert:  sprinkles08 replied 6 months ago.

You've had the coolant sensor unplugged with the key on, correct?

Customer: replied 6 months ago.
thats what happened...previous post...
Key on & connector off, LY wire 4.6v, O wire 9.6v, BY wire ohms to ground. With key OFF; LY wire 0v, O wire & BY wires both ohm to ground. So, I'm getting stray voltage to the orange wire that should be sending volts to the gauge from the #2 pin of the sensor. I need a picture of the wire harness routing of that circuit. Also, is it possible that the cluster could be the problem and have a short to power that is causing the O wire to carry the 9.6v?
Expert:  sprinkles08 replied 6 months ago.
You would have set the code yourself with it unplugged and the key on. Did you clear the code, run the engine and allow the problem to happen and then check again?

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