Tranny wont downshift
#11
10-08-2007 | 01:35 PM
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From: Pleasant Grove, UT
RE: Tranny wont downshift
so looks like i need to get the codes taken care of and should clear up my shifting problem, i will ahve ot get that done and let you guys know. you guys are champs, thanks for all the help
#12
10-08-2007 | 01:42 PM
RE: Tranny wont downshift
Hmm..
P0118 - Engine Coolant Temperature (ECT) Sensor Circuit High Voltage
P0122 - Throttle Position Sensor Circuit Low Voltage
So it seems that something is amiss with one or both of these sensors. Both of these sensors share a ground back to the PCM so it could be a wiring problem that is feeding voltage through the ground on the TPS/ECT that is causing a low readin on the TPS due to its configuration, and a high reading on the ECT. With the ignition off, check for continuity to ground on the black wire from both sensors. Then with the ignition on, check for continuity to the positive terminal of the battery. Inspect the harness from the ECT & TPS for any signs of damage. If you notice a damaged harness covering, open it up and inspect the wires inside.
P0118 - Engine Coolant Temperature (ECT) Sensor Circuit High Voltage
P0122 - Throttle Position Sensor Circuit Low Voltage
So it seems that something is amiss with one or both of these sensors. Both of these sensors share a ground back to the PCM so it could be a wiring problem that is feeding voltage through the ground on the TPS/ECT that is causing a low readin on the TPS due to its configuration, and a high reading on the ECT. With the ignition off, check for continuity to ground on the black wire from both sensors. Then with the ignition on, check for continuity to the positive terminal of the battery. Inspect the harness from the ECT & TPS for any signs of damage. If you notice a damaged harness covering, open it up and inspect the wires inside.
The Engine Coolant Temperature (ECT) sensor is a thermistor, a resistor which changes value based on the temperature, mounted in the engine coolant passage. A low coolant temperature produces a high resistance of 100,000 ohms at -40°C (-40°F) while a high temperature causes a low resistance of 70 ohms at 130°C (266°F) .
The Vehicle Control Module (VCM) supplies a 5 volt signal to the engine coolant temperature sensor through a resistor in the VCM and then measures the voltage. The voltage will be high when the engine is cold. The voltage will be low when the engine is hot. By measuring the voltage, the VCM calculates the engine coolant temperature. The engine coolant temperature affects most systems the VCM controls. The scan tool displays the engine coolant temperature in degrees. After engine startup, the temperature should rise steadily to about 90°C (194°F) , then stabilize when the thermostat opens. If the engine has not been run for several hours or overnight, the engine coolant temperature and the intake air temperature displays should be close to each other. When the VCM detects a malfunction in the ECT sensor circuit, the following DTCs will set:
* DTC P0117 Circuit Low
* DTC P0118 Circuit High
* DTC P0125 Excessive Time to Closed Loop
* DTC P1114 Circuit Intermittent Low
* DTC P1115 Circuit Intermittent High
The above DTCs contain a table in order to check for sensor resistance values that are relative to temperature.
The Vehicle Control Module (VCM) supplies a 5 volt signal to the engine coolant temperature sensor through a resistor in the VCM and then measures the voltage. The voltage will be high when the engine is cold. The voltage will be low when the engine is hot. By measuring the voltage, the VCM calculates the engine coolant temperature. The engine coolant temperature affects most systems the VCM controls. The scan tool displays the engine coolant temperature in degrees. After engine startup, the temperature should rise steadily to about 90°C (194°F) , then stabilize when the thermostat opens. If the engine has not been run for several hours or overnight, the engine coolant temperature and the intake air temperature displays should be close to each other. When the VCM detects a malfunction in the ECT sensor circuit, the following DTCs will set:
* DTC P0117 Circuit Low
* DTC P0118 Circuit High
* DTC P0125 Excessive Time to Closed Loop
* DTC P1114 Circuit Intermittent Low
* DTC P1115 Circuit Intermittent High
The above DTCs contain a table in order to check for sensor resistance values that are relative to temperature.
#13
10-08-2007 | 11:19 PM
BF Veteran
Joined: May 2005
Posts: 3,890
From: Central Illinois
RE: Tranny wont downshift
Got any squirrels eating nuts on your engine?
#14
10-09-2007 | 07:24 AM
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From: Pleasant Grove, UT
RE: Tranny wont downshift
cant say that i do
#15
10-09-2007 | 08:46 AM
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From: Pleasant Grove, UT
RE: Tranny wont downshift
if my Engine Coolant Temperature was having troubles wouldnt that effect my temp gauge in the dash? it seems to be working properly, starts out cold and as i start driving and it warms up it moves its way up to just below 210.
a TPS is $35 and a ECT is $15, but i am wondering if the gauge works if i should replace the ECT. i looked at my wires last night didnt see any damage, did not test the TPS to see if it is faulty yet, gets dark to soon this time of year : (
also should i have squirrels eating nuts on top of my engine? i thought they took the squirrels out of this motor and put in some racoons?
/my lame attempt to make a funny
a TPS is $35 and a ECT is $15, but i am wondering if the gauge works if i should replace the ECT. i looked at my wires last night didnt see any damage, did not test the TPS to see if it is faulty yet, gets dark to soon this time of year : (
also should i have squirrels eating nuts on top of my engine? i thought they took the squirrels out of this motor and put in some racoons?
/my lame attempt to make a funny
#16
10-09-2007 | 09:04 AM
RE: Tranny wont downshift
Two different sensors. The sending unit for the gauge is in the side of the head on the driver's side. The ECT is on the intake.
Tim (hanr3) had a bout with some squirrels chewing on his wiring, me thinks. LOL
Tim (hanr3) had a bout with some squirrels chewing on his wiring, me thinks. LOL
#17
10-09-2007 | 09:06 AM
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From: Pleasant Grove, UT
RE: Tranny wont downshift
oh, i was looking at the wiring on the wrong sensor for the ECT then, where on the intake is the ECT at?
#18
10-09-2007 | 09:08 AM
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From: Pleasant Grove, UT
RE: Tranny wont downshift
if one of these two is acting up will it effect the other since they share the same ground ?
#19
10-09-2007 | 09:19 AM
RE: Tranny wont downshift
Sorry, the ECT is in the driver's side cylinder head. Looking back over my references, I can not find a clear answer as to where the gauge sensor is located, but I suspect it is in the passenger side cylinder head. At any rate, the ECT will be a two wire sensor and should be on the driver's side cylinder head between the back two cylinders.
#20
10-09-2007 | 09:26 AM
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From: Pleasant Grove, UT
RE: Tranny wont downshift
ok, so i was looking at the correct one, i am not looking forward ot changing it if i need to, its in a lame spot, looks about as bad as the 3rd spark plug...