Hummer H1 Service Manual page 253

5-54 Transmission/Transfer Case
Conditions For Setting The DTC
• No DTCs P1117 or P1118.
• No OSS sensor DTC P0502.
• No A/T ISS sensor. DTC P0716 or P0717.
• No A/T Component Slipping DTC P1870.
• The system voltage is 10.0 - 16.0 volts.
• The engine is running greater than 475 rpm for at least
30 seconds.
• The engine coolant temperature (ECT) is greater than
176° F (80° C).
• The TFT is -40 to +70° F (-40 to + 21 ° C) at start up.
• The ECT has changed at least 122° F (50 ° C) since start
up.
• The vehicle speed is greater than 3 mph for at least 900
seconds (15 minutes).
• The TCC slip speed is greater than 60 rpm for at least
850 seconds (14 minutes)>
• DTC P0711 sets if all of the above conditions have been
met and one of the following conditions exist:
- Non TFT change: The TFT has not changed more
than 4° F (2.25° C), in more than 80 seconds.
- An unrealistic temperature change: The TFT has
changed more than 68°F (20 ° C) 14 times in 7 sec-
onds.
Action Taken When The DTC Sets
• The PCM uses a TFT default value of 280° F (140° C).
• The PCM freezes shift adapts.
• The PCM illuminates the Malfunction Indicator Lamp
(MIL).
Conditions For Clearing The MIL/DTC
• For California Emissions only, the PCM turns off the
MIL after three consecutive ignition cycles without a
failure report.
• The DTC can be cleared using the scan tool. The DTC
will be cleared when the vehicle has achieved 40 warm-
up cycles without a failure reported.
• The PCM will cancel the DTC default actions when the
fault no longer exists and the ignition is OFF long
enough to power down the PCM.
Diagnostic Aids
• When diagnosing for a possible intermittent short or
open condition, wiggle the wiring harness while observ-
ing test equipment for a change.
• If any engine DTCs are present diagnose and clear these
DTCs first. Then check to see if the transmission DTCs
have reset.
_____________________________________________
Test Description
• The numbers below refer to the step numbers on the di-
agnostic chart.
2. This step tests for proper A/T fluid level and condition.
3. This step verifies that the vehicle sets DTC P0711.
5. The 12-volt test lamp is used as a fixed resistance.
6. Perform this step in order to ensure that the PCM monitors
circuit 1227.
8. The TFT Sensor is part of the A/T Wiring Harness Assem-
bly
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