Hummer H1 Service Manual page 258

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Step
1 Perform transmission fluid checking procedure.
Was the fluid checking Procedure performed?
2 1. Install the scan tool.
2. Turn the ignition switch to "on" position.
Important: Before clearing DTC(s), use the scan tool to record "Freeze
Frame" and "Failure Records" for reference, as data will be lost when
the "Clear Info" function is used.
3. Record the DTC "Freeze Frame" and "Failure Records."
Does the scan tool display a "TFT Sensor" signal voltage less than
shown in the value column?
3 1. Turn the ignition "off."
2. Disconnect the transmission 20-way harness connector.
3. Turn the ignition "on."
Does the scan tool display a "TFT Sensor" signal voltage greater than
shown in the value column?
4 1. Install 05743837 Jumper Harness on transmission side of the 20-
way connector.
2. Using multimeter and Connector Test Adapter Kit, measure resis-
tance between terminals "L" and "M."
Is resistance high?
5 1. Remove transmission oil pan.
2. Check the internal wiring harness for a short to ground.
Was a problem found?
6 1. Disconnect the internal wiring harness.
2. Measure the resistance of TFT sensor.
Is the resistance high?
7 Replace the internal wiring harness.
Is the replacement complete?
8 Check circuit 359 for short to ground.
Was a problem found?
9 Check the TCM/PCM for faulty connections.
Was a problem found?
10 Replace the TCM/PCM.
Is the replacement complete?
11 1. After the repair is complete, use the scan tool to select "DTC," then
"Clear Info" function.
2. Select "Specific DTC" and enter DTC "P0712."
3. Ensure the following conditions are met:
• TFT sensor indicates a voltage greater than 0.33 volts for 10 sec-
onds.
Has the last test failed?
05745159
DTC P0712 Fluid Temperature Circuit Low/High
Action
Transmission/Transfer Case
Value
—
0.2 volts
4.92 volts
Check
charging
system
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—
—
—
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5-59
Yes No
Go to Step
2 —
Refer to
Go to Step Diagnostic
3 Aids
Go to Step Go to Step
4 8
Refer to
Diagnostic Go to Step
Aids 6
Go to Step Go to Step
7 6
Refer to
Diagnostic Go to Step
Aids 7
Go to Step
11 —
Go to Step Go to Step
11 9
Go to Step Go to Step
11 10
Go to Step
11 —
Begin
diagnosis Repair ver-
again, Go ified, exit
to Step 1 DTC table.