Hummer H1 Service Manual page 322

___________________________________________
®
Action Taken When The DTC Sets
• Assume "Low" state when stuck "off' and "High" state
when stuck "on".
• Freeze shift adapts from being updated.
• The PCM will illuminate the warning lamp.
Conditions For Clearing DTC
• The PCM will turn off the warning lamp after three con-
secutive ignition cycles without a failure reported.
• 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 cycled "off"
long enough to power down the PCM.
05745159
Transmission/Transfer Case
Diagnostic Aids
• Inspect the wiring for poor electrical connections at the
PCM and at the transmission 20-way connector. Look
for possible bent, backed out, deformed or damaged ter-
minals. Check for weak terminal tension as well. Also
check for a chafed wire that could short to bare metal or
other wiring. Inspect for a broken wire inside the insula-
tion.
• When diagnosing for a possible intermittent short or
open condition, move or massage the wiring harness
while observing test equipment for a change.
• If any engine DTCs or TP Sensor codes are present di-
agnose 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 diagnostic
chart.
2. This test checks for voltage input to the 4WD indica-
tor assembly.
3. This test checks for voltage input to the selector quad-
rant switch through the 4WD indicator assembly.
5-123