Hummer H1 Service Manual page 312

Section 5 Transmission/Trans er Case
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Conditions For Clearing DTC
1. The PCM turns OFF the MIL after three consecutive igni-
tion cycles without a failure reported.
2. A scan tool can clear the DTC from the PCM history. The
PCM clears the DTC from the PCM history if the vehicle
completes 40 warm-up cycles without a failure reported.
3. The PCM cancels the DTC default actions when the fault
no longer exists and the ignition is OFF long enough in
order to power down the PCM.
Diagnostic Aids
• Inspect the wiring for poor electrical connections at the
PCM.
• Inspect the wiring for poor electrical connections at the
transmission 20-way connector. Look for the following
problems:
• A bent terminal
• A backed out terminal
• A damaged terminal
• Poor terminal tension
• A chafed wire
• A broken wire inside the insulation
• When diagnosing for an intermittent short or open, mas-
sage the wiring harness while watching the test equipment
for a change.
• First diagnose and clear any engine DTCs that are present.
Then inspect for any transmission DTCs that may have reset.
Test Description
The numbers below refer to the step numbers on the diagnostic
table.
4. This step tests for voltage to the TCC PWM Sol. Valve.
6. This step tests the ability of the PCM and wiring to control
the ground circuit.
8. This step tests the resistance of the TCC PWM Sol. Valve
and the internal wiring harness
12. If the internal wiring harness is open, do not repair the in-
ternal wiring harness. You must replace the Automatic
Transmission Wiring Harness Assembly
05745159
Transmission/Transfer Case 5-113