with joecarter85...right on.
94 LT1 coolent sensor
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From: Sitting in his Nowhere land Hanover Pa
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94 LT1 coolent sensor
for my 94 the digital reading stays at 142* while the analog gauge reads around 200*. thus throws a code of 15. keeping the the car into a closed loop system. checked the OHM from the sensor from the water pump to the ECM and it checked out fine. so the FSM says its either the switch which we replaced 3 times or the dash cluster. or could it be the ECM.
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From: Tampa Florida
for my 94 the digital reading stays at 142* while the analog gauge reads around 200*. thus throws a code of 15. keeping the the car into a closed loop system. checked the OHM from the sensor from the water pump to the ECM and it checked out fine. so the FSM says its either the switch which we replaced 3 times or the dash cluster. or could it be the ECM.
Thread Starter
Team Owner
Joined: Feb 2003
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From: Sitting in his Nowhere land Hanover Pa
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pulled the code using a scanner and got code #15
Le Mans Master
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From: Tampa Florida
Instructor
Joined: Jul 2007
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From: Austin Texas
The digital temp. readout, which is also the temp. reading used by your PCM, is controlled by the temp sensor mounted on the front of your WP. If it is reading 142*, then I would recommend replacing it. About $15. That 142* will mess up the PCM, and probably never let it go "closed loop".
The analog gauge reading of 200* sounds right on, and this is a single wire temp sensor located on the passenger side of the block, just below and to the right of the #8 cylinder. This temp. sensor is ONLY used for the analog gauge and not used by your PCM.
code 15 - Coolant temperature sensor signal indicates a temperature colder than -56 F.
Did you say you tried 3 different temp sensors, and you always get 142* ? (you used the word "switch")
-check the integrity of the connector to the temp. sensor
-I would check continuity from your temp. sensor connector back to PCM ( 2 wire connector, both go back to PCM))
-with key in "on" position, but not runnig, the non-black lead wire should read +5v, which is reference voltage supplied
from the PCM to the temp sensor. The other wire(black) is a digital PCM ground (not chassis ground).
When engine cold, your dig. should be reading approx. outside ambient temperature (but usually reads higher). If you have tried 3 temp. sensors, and all read 142*, I would suspect a problem with
1) connector
2) bad contact at PCM connector (inspect and re-seat)
3) open or short somewhere between connector and PCM
4) I would suspect a bad PCM as last resort.
The analog gauge reading of 200* sounds right on, and this is a single wire temp sensor located on the passenger side of the block, just below and to the right of the #8 cylinder. This temp. sensor is ONLY used for the analog gauge and not used by your PCM.
code 15 - Coolant temperature sensor signal indicates a temperature colder than -56 F.
Did you say you tried 3 different temp sensors, and you always get 142* ? (you used the word "switch")
-check the integrity of the connector to the temp. sensor
-I would check continuity from your temp. sensor connector back to PCM ( 2 wire connector, both go back to PCM))
-with key in "on" position, but not runnig, the non-black lead wire should read +5v, which is reference voltage supplied
from the PCM to the temp sensor. The other wire(black) is a digital PCM ground (not chassis ground).
When engine cold, your dig. should be reading approx. outside ambient temperature (but usually reads higher). If you have tried 3 temp. sensors, and all read 142*, I would suspect a problem with
1) connector
2) bad contact at PCM connector (inspect and re-seat)
3) open or short somewhere between connector and PCM
4) I would suspect a bad PCM as last resort.
Last edited by joecarter85; Jan 25, 2009 at 12:12 AM.
Thread Starter
Team Owner
Joined: Feb 2003
Posts: 54,107
Likes: 9,424
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
The digital temp. readout, which is also the temp. reading used by your PCM, is controlled by the temp sensor mounted on the front of your WP. If it is reading 142*, then I would recommend replacing it. About $15. That 142* will mess up the PCM, and probably never let it go "closed loop".
The analog gauge reading of 200* sounds right on, and this is a single wire temp sensor located on the passenger side of the block, just below and to the right of the #8 cylinder. This temp. sensor is ONLY used for the analog gauge and not used by your PCM.
code 15 - Coolant temperature sensor signal indicates a temperature colder than -56 F.
Did you say you tried 3 different temp sensors, and you always get 142* ? (you used the word "switch")
-check the integrity of the connector to the temp. sensor
-I would check continuity from your temp. sensor connector back to PCM ( 2 wire connector, both go back to PCM))
-with key in "on" position, but not runnig, the non-black lead wire should read +5v, which is reference voltage supplied
from the PCM to the temp sensor. The other wire(black) is a digital PCM ground (not chassis ground).
When engine cold, your dig. should be reading approx. outside ambient temperature (but usually reads higher). If you have tried 3 temp. sensors, and all read 142*, I would suspect a problem with
1) connector
2) bad contact at PCM connector (inspect and re-seat)
3) open or short somewhere between connector and PCM
4) I would suspect a bad PCM as last resort.
The analog gauge reading of 200* sounds right on, and this is a single wire temp sensor located on the passenger side of the block, just below and to the right of the #8 cylinder. This temp. sensor is ONLY used for the analog gauge and not used by your PCM.
code 15 - Coolant temperature sensor signal indicates a temperature colder than -56 F.
Did you say you tried 3 different temp sensors, and you always get 142* ? (you used the word "switch")
-check the integrity of the connector to the temp. sensor
-I would check continuity from your temp. sensor connector back to PCM ( 2 wire connector, both go back to PCM))
-with key in "on" position, but not runnig, the non-black lead wire should read +5v, which is reference voltage supplied
from the PCM to the temp sensor. The other wire(black) is a digital PCM ground (not chassis ground).
When engine cold, your dig. should be reading approx. outside ambient temperature (but usually reads higher). If you have tried 3 temp. sensors, and all read 142*, I would suspect a problem with
1) connector
2) bad contact at PCM connector (inspect and re-seat)
3) open or short somewhere between connector and PCM
4) I would suspect a bad PCM as last resort.
Thread Starter
Team Owner
Joined: Feb 2003
Posts: 54,107
Likes: 9,424
From: Sitting in his Nowhere land Hanover Pa
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2015 C2 of Year Finalist
fired the car up this morning. no codes were thrown the digital read out was working like it should. so now what
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Thread Starter
Team Owner
Joined: Feb 2003
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From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
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Drifting
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From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
ground problem?
have you experienced any other 'wierd' electrical problems?
If so, I would suspect a problem with one or more ground points (e.g. driver side bell housing).
Otherwise, suspect a wire or connector problem to the temp sender or PCM. Suggest with key on (but engine not running) try moving the wire/harness around and see if the digital temp changes.
If so, I would suspect a problem with one or more ground points (e.g. driver side bell housing).
Otherwise, suspect a wire or connector problem to the temp sender or PCM. Suggest with key on (but engine not running) try moving the wire/harness around and see if the digital temp changes.
Thread Starter
Team Owner
Joined: Feb 2003
Posts: 54,107
Likes: 9,424
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
have you experienced any other 'wierd' electrical problems?
If so, I would suspect a problem with one or more ground points (e.g. driver side bell housing).
Otherwise, suspect a wire or connector problem to the temp sender or PCM. Suggest with key on (but engine not running) try moving the wire/harness around and see if the digital temp changes.
If so, I would suspect a problem with one or more ground points (e.g. driver side bell housing).
Otherwise, suspect a wire or connector problem to the temp sender or PCM. Suggest with key on (but engine not running) try moving the wire/harness around and see if the digital temp changes.
