Temp gage
Thread Starter
5th Gear
Joined: Dec 2012
Posts: 5
Likes: 0
Temp gage
Hey Guys. Got a 02 LS1, 60,000 miles that I dont drive much anymore. Changed oil this a.m., started engine and temp gage went all the way right. Replaced temp sending unit with no success. Fans come on and engine runs very rough. Does not run hot. Engine ran perfect went parked 2 weeks ago. Cant find any damaged wires. 25 miles from nearest repair shop. Any ideas? Thanks
Racer
Joined: Jan 2005
Posts: 375
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From: Montreal Drive it like you test it !
Sometimes it is difficult to see if a wire is broken or not. Failure might be hidden by some parts. I would take a digital voltmeter and check if I get the same voltage at sensor than at computer connectors. Pin 49 of the PCM Connector C2 (blue). Circuit 410 on my 97, but might differ for your year. If the wire is yellow, this is a good sign.
any codes such as P0116 Engine coolant temperature ETC Sensor performance.
my 2 cents if you want to start troubleshooting before the experts reply...
any codes such as P0116 Engine coolant temperature ETC Sensor performance.
my 2 cents if you want to start troubleshooting before the experts reply...
Last edited by vette747; Dec 12, 2014 at 09:50 PM.
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
Pull the codes.
Sounds like the sensor wire is shorted to ground. Unplug the ect sensor and turn the key on. If it still all the way to the right the signal wire is probably shorted to ground. It should stay all the way cold with the sensor unplugged.
Here is some info that might help.
Let us no what happens after you check it.
DTC P0117
CIRCUIT DESCRIPTION
The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.
CONDITIONS FOR RUNNING THE DTC
The engine run time is more than 10 seconds .
OR
The engine run time is less than 10 seconds when IAT is less than 50°C (122°F) .
CONDITIONS FOR SETTING THE DTC
The ECT sensor temperature is more than 139°C (282°F) for more than 20 seconds .
ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
An overheating condition may cause this DTC to set.
After starting the engine, the ECT should rise steadily to about 90°C (194°F) then stabilize when the thermostat opens.
Use the Temperature vs. Resistance table to test the ECT sensor at various temperature levels to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns. Refer to Temperature vs Resistance.
If the condition is suspected of being intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies
Sounds like the sensor wire is shorted to ground. Unplug the ect sensor and turn the key on. If it still all the way to the right the signal wire is probably shorted to ground. It should stay all the way cold with the sensor unplugged.
Here is some info that might help.
Let us no what happens after you check it.
DTC P0117
CIRCUIT DESCRIPTION
The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.
CONDITIONS FOR RUNNING THE DTC
The engine run time is more than 10 seconds .
OR
The engine run time is less than 10 seconds when IAT is less than 50°C (122°F) .
CONDITIONS FOR SETTING THE DTC
The ECT sensor temperature is more than 139°C (282°F) for more than 20 seconds .
ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
An overheating condition may cause this DTC to set.
After starting the engine, the ECT should rise steadily to about 90°C (194°F) then stabilize when the thermostat opens.
Use the Temperature vs. Resistance table to test the ECT sensor at various temperature levels to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns. Refer to Temperature vs Resistance.
If the condition is suspected of being intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies
Thread Starter
5th Gear
Joined: Dec 2012
Posts: 5
Likes: 0
Sometimes it is difficult to see if a wire is broken or not. Failure might be hidden by some parts. I would take a digital voltmeter and check if I get the same voltage at sensor than at computer connectors. Pin 49 of the PCM Connector C2 (blue). Circuit 410 on my 97, but might differ for your year. If the wire is yellow, this is a good sign.
any codes such as P0116 Engine coolant temperature ETC Sensor performance.
my 2 cents if you want to start troubleshooting before the experts reply...
any codes such as P0116 Engine coolant temperature ETC Sensor performance.
my 2 cents if you want to start troubleshooting before the experts reply...
but temp gage works correctly now.
Thread Starter
5th Gear
Joined: Dec 2012
Posts: 5
Likes: 0
Pull the codes.
Sounds like the sensor wire is shorted to ground. Unplug the ect sensor and turn the key on. If it still all the way to the right the signal wire is probably shorted to ground. It should stay all the way cold with the sensor unplugged.
Here is some info that might help.
Let us no what happens after you check it.
DTC P0117
CIRCUIT DESCRIPTION
The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.
CONDITIONS FOR RUNNING THE DTC
The engine run time is more than 10 seconds .
OR
The engine run time is less than 10 seconds when IAT is less than 50°C (122°F) .
CONDITIONS FOR SETTING THE DTC
The ECT sensor temperature is more than 139°C (282°F) for more than 20 seconds .
ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
An overheating condition may cause this DTC to set.
After starting the engine, the ECT should rise steadily to about 90°C (194°F) then stabilize when the thermostat opens.
Use the Temperature vs. Resistance table to test the ECT sensor at various temperature levels to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns. Refer to Temperature vs Resistance.
If the condition is suspected of being intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies
Sounds like the sensor wire is shorted to ground. Unplug the ect sensor and turn the key on. If it still all the way to the right the signal wire is probably shorted to ground. It should stay all the way cold with the sensor unplugged.
Here is some info that might help.
Let us no what happens after you check it.
DTC P0117
CIRCUIT DESCRIPTION
The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.
CONDITIONS FOR RUNNING THE DTC
The engine run time is more than 10 seconds .
OR
The engine run time is less than 10 seconds when IAT is less than 50°C (122°F) .
CONDITIONS FOR SETTING THE DTC
The ECT sensor temperature is more than 139°C (282°F) for more than 20 seconds .
ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
An overheating condition may cause this DTC to set.
After starting the engine, the ECT should rise steadily to about 90°C (194°F) then stabilize when the thermostat opens.
Use the Temperature vs. Resistance table to test the ECT sensor at various temperature levels to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns. Refer to Temperature vs Resistance.
If the condition is suspected of being intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies
