Hummer H2. Manual - part 2420

Fig. 7: Automatic Transmission Fluid Temperature (TFT) Sensor
Courtesy of GENERAL MOTORS CORP.

Circuit Description

The automatic transmission fluid temperature (TFT) sensor is part of the automatic transmission fluid pressure
(TFP) manual valve position switch. The TFT sensor is a resistor, or thermistor, which changes value based on
temperature. The sensor has a negative-temperature coefficient. This means that as the temperature increases,
the resistance decreases, and as the temperature decreases, the resistance increases. The powertrain control
module (PCM) supplies a 5-volt reference signal to the sensor on the TFT sensor signal circuit and measures the
voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the PCM

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance
becomes less and the signal voltage decreases. The PCM uses this information to control shift quality and
torque converter clutch apply.

When the PCM detects a continuous open or short to voltage in the TFT signal circuit or the TFT sensor, then
DTC P0713 sets. DTC P0713 is a type C DTC.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The TFT sensor indicates a signal voltage greater than 4.92 volts for 400 seconds (6.8 minutes).

Action Taken When the DTC Sets

The PCM does not illuminate the malfunction indicator lamp (MIL).

The PCM determines a default TFT using one of the following:

1. If any ECT DTCs P0117 or P0118 are set, then the default TFT is equal to 135°C (275°F).

2. If the ECT is 125°C (257°F) or more, then the default TFT is equal to 135°C (275°F).

3. If the engine run time is less than 300 seconds and:

No intake air temperature (IAT) DTCs P0112 or P0113 are set and IAT is available, then the
default TFT is equal to IAT.

Any IAT DTCs P0112 or P0113 are set or IAT is NOT available, then the default TFT is
equal to 90°C (194°F).

4. If the engine run time is greater than 300 seconds and no IAT DTCs P0112 or P0113 are set and

IAT is available and ECT is between 40 and 125°C (104 and 257°F) and:

IAT at startup is less than 15°C (59°F), then the default TFT is equal to the ECT plus 5°C (8°
F).

IAT at startup is greater than 35°C (95°F), then the default TFT is equal to the ECT plus 10°
C (16°F).

IAT at startup is between 15 and 35°C (59 and 95°F), then the default TFT is equal to the
ECT.

5. If the engine run time is greater than 300 seconds and any IAT DTCs P0112 or P0113 are set or

IAT is NOT available, then the default TFT is equal to the ECT.

6. If the engine run time is greater than 300 seconds and ECT is less than 40°C (104°F) or more, then

the default TFT is equal to 60°C (140°F).

The PCM freezes shift adapts from being updated.

The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM

IMPORTANT: The actions listed below are in order of highest to lowest priority.

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

stores this information as Failure Records.

The PCM stores DTC P0713 in PCM history.

Conditions for Clearing the DTC

A scan tool can clear the DTC.

The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-
emission-related diagnostic fault occurring.

The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is
OFF long enough in order to power down the PCM.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

5: This step tests the TFT sensor signal circuit for being shorted to another circuit within the
transmission. If the TFT sensor signal circuit shorts to another circuit, which is carrying voltage greater
than five volts, the TFT sensor would become open.

6: This step tests the TFT sensor signal circuit for being shorted to voltage, which would be the cause for
the open in the TFT sensor.

DTC P0713

Step

Action

Value

(s)

Yes

Did you perform the Diagnostic System Check
- Engine Controls?

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls in

Engine Controls -

6.0L (LQ4)

1. Install a scan tool.

2. Turn ON the ignition, with the engine

OFF.

3. Record the DTC Failure Records.

4. Clear the DTC.

5. Select Trans. Fluid Temp. on the scan

tool.

IMPORTANT:

Before clearing the DTC, use the scan
tool in order to record the DTC Failure
Records. Using the Clear Info function
erases the Failure Records from the
PCM.

-39°C

(-38°

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

Does the scan tool display a Trans. Fluid Temp.
less than the specified value?

Go to Step 3

Go to Intermittent

Conditions in Engine

Controls - 6.0L (LQ4)

1. Turn OFF the ignition.

2. Disconnect the AT inline 20-way

connector. Additional DTCs may set.

3. Install the J 44152 Jumper Harness (20

pins) on the transmission side of the AT
inline 20-way connector.

4. Using the DMM and the J 35616 GM

Terminal Test Kit, measure the resistance
between terminals L and M of the J
44152 .

Refer to Automatic Transmission Inline 20-
Way Connector End View .Does the
resistance measure less than the specified
value?

100 K

ohm

Go to Step 7

Go to Step 4

1. Test the signal circuit of the TFT sensor

for an open between the AT inline 20-
way connector and the TFT sensor.

2. Test the low reference circuit of the TFT

sensor for an open between the AT inline
20-way connector and the TFT sensor.

Refer to Testing for Continuity in Wiring
Systems.Did you find an open condition?

Go to Step 8

Go to Step 5

Measure the resistance between terminal L and
all other terminals of the J 44152 .
Does the resistance measure less than the
specified value?

1000

ohm

Go to Step 10

Go to Step 6

Test the signal circuit of the TFT sensor for a
short to voltage between the PCM connector
and the AT inline 20-way connector.
Refer to Testing for a Short to Voltage and
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filetype="sgml" extrefid="i162420">Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 9

1. Test the signal circuit of the TFT sensor

for an open between the PCM connector
and the AT inline 20-way connector.

2. Test the low reference circuit of the TFT

sensor for an open between the PCM

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

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