No Cold Overdrive
Thread Starter
Joined: 07-01-2011
Posts: 7
From: metro detroit michigan
No Cold Overdrive
I have a 2009 with a 2.2. When the vehicle is cold the car does not shift into overdrive. The vehicle has about 45000 miles on it. When I took it into the dealer it cost me 100.00 for them to say what its doing is normal. So I took it to another dealer, I explained to the service advisor "while the vehicle is cold it does not shift into overdrive, but after it warms up it does, so depending on the temps outside will determine how long it takes to shift into overdrive. Once it shift into overdrive there are no problems. No codes ever come up, but the problem is still there. I NEED HELP.
Senior Member
Joined: 07-30-2011
Posts: 134
From: MN
Senior Member
Joined: 06-26-2006
Posts: 1,876
From: San Bernardino, California
Transmission Fluid Temperature Sensor
A TFT sensor or transmission fluid temperature sensor is one of many sensors utilized by the transmission control module. It is the located in the valve body or oil pan of the transmission or transaxle. The TCM uses this sensor to monitor the temperature of the transmission fluid.
Thermistor's like the TFT alter resistance as temperature changes. We know with ohms law that as resistance changes the voltage signal changes as well. By increasing resistance we lower the voltage signal to the TCM. Most transmission fluid temperature sensors are NTC or negative temperature coefficient. This means that resistance decreases as the temperature increases. The opposite is true for a positive temperature coefficient sensor.
With these sensors the resistance increases as the temperature increases. Both of these temperature sensors use varying resistance to control the signal voltage to the TCM. They are similar to an ECT or engine coolant temperature sensor that monitors coolant temperature for the PCM.
The TCM uses this input along with other sensors to control the transmissions operations. When the temperature is cold the TCM will delay torque converter clutch or TCC operation until the fluid reaches a certain temperature. The TCM will engage the TCC mechanically connecting the input shaft to the engine in an attempt to cool the fluid if it gets too hot. If the temperature reaches a threshold set by the manufacturer: 300° F or so, the TCM will set a code and illuminate the MIL to inform the driver. A faulty TFT sensor will affect the torque converter and the transmissions line pressure.
The sensors output can monitored with a scan tool and the results compared to the actual temperature. You can use a temperature probe attached to a DMM and then lowered down the dipstick tube. A DMM is also used to measure the resistance of the sensor. The sensors resistance can be checked at room temperature, cooled, or warmed in hot water and checked against manufactures specifications. The fault may be in the sensor, the sensors circuit, or the TCM.
A TFT sensor or transmission fluid temperature sensor is one of many sensors utilized by the transmission control module. It is the located in the valve body or oil pan of the transmission or transaxle. The TCM uses this sensor to monitor the temperature of the transmission fluid.
Thermistor's like the TFT alter resistance as temperature changes. We know with ohms law that as resistance changes the voltage signal changes as well. By increasing resistance we lower the voltage signal to the TCM. Most transmission fluid temperature sensors are NTC or negative temperature coefficient. This means that resistance decreases as the temperature increases. The opposite is true for a positive temperature coefficient sensor.
With these sensors the resistance increases as the temperature increases. Both of these temperature sensors use varying resistance to control the signal voltage to the TCM. They are similar to an ECT or engine coolant temperature sensor that monitors coolant temperature for the PCM.
The TCM uses this input along with other sensors to control the transmissions operations. When the temperature is cold the TCM will delay torque converter clutch or TCC operation until the fluid reaches a certain temperature. The TCM will engage the TCC mechanically connecting the input shaft to the engine in an attempt to cool the fluid if it gets too hot. If the temperature reaches a threshold set by the manufacturer: 300° F or so, the TCM will set a code and illuminate the MIL to inform the driver. A faulty TFT sensor will affect the torque converter and the transmissions line pressure.
The sensors output can monitored with a scan tool and the results compared to the actual temperature. You can use a temperature probe attached to a DMM and then lowered down the dipstick tube. A DMM is also used to measure the resistance of the sensor. The sensors resistance can be checked at room temperature, cooled, or warmed in hot water and checked against manufactures specifications. The fault may be in the sensor, the sensors circuit, or the TCM.
Senior Member
Joined: 01-13-2008
Posts: 4,708
From: Washington State, where it rains
The Overdrive/ TC lockup does not occur until you hit around 155 deg..this is normal..when its cold out it takes longer, its so you dont lug down the eng until its warmed up. Ive watched this several times to determine when it happens, so yours may be different as probably no two are the same. I also watched the temp rise during different outside temps and it doesnt like the cold, takes way longer to warm up while driving. this is the main reason fuel milage drops so bad in the winter time, takes much longer and car runs in cold mode( same as a choke on carb motors).
Thread Starter
Joined: 07-01-2011
Posts: 7
From: metro detroit michigan
I made a video on sat of my issue, I noticed on the video the outside temp was like about 50 degrees outside and it took almost 6 miles for the torque converter lockup to engage. After 4 years this is my first year having this issue.