So I go to pull codes from my car cuz the check engine light came on, and this are the codes I got 12,and 21 I think 21 is the coolant temp sensor out of range or bad not sure, and 12 I don't know.Any help would be great. Thanx
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92 LX All the bolt on's, and some.
2004 COBRA Pully,exhuast,Predator tune,upgraded heat exchanger, Tri Ax. For now.
This morning I went and got a Chilton's manual to see what the codes are, and I was right about code 21 ECT out of self test range.Does anyone know what that means, and do I to replace it? code 12 RPM unable to achieve upper test limit. I have no idea what that means.Help please thanx.
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92 LX All the bolt on's, and some.
2004 COBRA Pully,exhuast,Predator tune,upgraded heat exchanger, Tri Ax. For now.
You hopefully scanned KOER with the engine not warmed up, that'll throw the 21. The 12 means it can't idle down to its lowest level. Several things can cause that, including vacuum leaks.
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1992 Deep Emerald Green Mustang GT Hatch, 5 speed, 2.73s, Mac fenderwell cold air intake, '93 Cobra MAF, Mac 70mm throttle body & spacer, Explorer intakes, Mac unequal headers & offroad pipe, Magnaflow catback, Walbro 110lph fuel pump, Jet adjustable FPR, MSD Blaster coil, Accel 8mm wires, FRPP aluminum quadrant, UPR firewall adjuster, stock cable, Granatelli upper control arms.
Waiting to go on: Granatelli lower control arms, and GT40 Iron heads!
You hopefully scanned KOER with the engine not warmed up, that'll throw the 21. The 12 means it can't idle down to its lowest level. Several things can cause that, including vacuum leaks.
Actually the car was warmed up, I drove it for like 20 minutes to get to my friends shop, were I let it sit for 20 minutes, then warmed it up for 10 minutes with the scanner hooked up to it. Why do you say hopefully, is it a bad thing if it threw a 21 with the engine warmed up.Do you know of any other things besides a vacuum leak that can throw off a 12. I don't really know much about codes or what sets them off. Thanx for the info man. :thumbsup
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92 LX All the bolt on's, and some.
2004 COBRA Pully,exhuast,Predator tune,upgraded heat exchanger, Tri Ax. For now.
Code 21: Engine temp needs to be over 50°F or 180°F for it not to show up at the KOEO and KOER self-tests respectively...it's not necessarly a bad sensor. Suggest to make sure you get engine at op temp and re-run the test.
Code 12...like Meangreen92 mentioned, an idle set too high, or a bad Idle Air Controller (IAC).....LUK
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ACRONYMS:
LUK=Let Us Know, GL=Good Luck, LMK=Let Me Know, JIC=Just In Case, BTSTDTRT=Been There Seen That Done That Repaired That, YCYDYP=Your Car Your Dough Your Prerogative and the classic... DILLIGAS=Do I Look Like I Give A S***
1986 GT-X303 cam, 289 heads, 1.72, Holley 700cfm DP, RG 4+1 Trans.
Read your last post....one check you may want to do, after warming up the engine, Ign on....check the voltage reading from the coolant sensor(Lt Grn/Yel wire) with a VOM to ground....it should have an output between 1.02vdc for a temp of 158°, and .6vdc for a temp of 196°F....if you need a wiring diagram use this one(Courtesy of TMoss and Veryuseful.com). LUK
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ACRONYMS:
LUK=Let Us Know, GL=Good Luck, LMK=Let Me Know, JIC=Just In Case, BTSTDTRT=Been There Seen That Done That Repaired That, YCYDYP=Your Car Your Dough Your Prerogative and the classic... DILLIGAS=Do I Look Like I Give A S***
1986 GT-X303 cam, 289 heads, 1.72, Holley 700cfm DP, RG 4+1 Trans.
Code 21: Engine temp needs to be over 50°F or 180°F for it not to show up at the KOEO and KOER self-tests respectively...it's not necessarly a bad sensor. Suggest to make sure you get engine at op temp and re-run the test.
Code 12...like Meangreen92 mentioned, an idle set too high, or a bad Idle Air Controller (IAC).....LUK
I'm going to check out the idle, and the IAC. Thanx .:thumbsup
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92 LX All the bolt on's, and some.
2004 COBRA Pully,exhuast,Predator tune,upgraded heat exchanger, Tri Ax. For now.
Read your last post....one check you may want to do, after warming up the engine, Ign on....check the voltage reading from the coolant sensor(Lt Grn/Yel wire) with a VOM to ground....it should have an output between 1.02vdc for a temp of 158°, and .6vdc for a temp of 196°F....if you need a wiring diagram use this one(Courtesy of TMoss and Veryuseful.com). LUK
Thanx for the info I'm going to try this also.Got get a meter. :thumbsup
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92 LX All the bolt on's, and some.
2004 COBRA Pully,exhuast,Predator tune,upgraded heat exchanger, Tri Ax. For now.
Also, make sure you don't have a 160º thermostat - those never warm up a 5.0, 180º is about as low as you want to go.
I had a 12, when I got my car, and the thing that cleared it, was replacing my TAB solenoid, which had been giving me an 82.
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1992 Deep Emerald Green Mustang GT Hatch, 5 speed, 2.73s, Mac fenderwell cold air intake, '93 Cobra MAF, Mac 70mm throttle body & spacer, Explorer intakes, Mac unequal headers & offroad pipe, Magnaflow catback, Walbro 110lph fuel pump, Jet adjustable FPR, MSD Blaster coil, Accel 8mm wires, FRPP aluminum quadrant, UPR firewall adjuster, stock cable, Granatelli upper control arms.
Waiting to go on: Granatelli lower control arms, and GT40 Iron heads!
Need Help With Codes 
