Hummer H1 Service Manual page 283

5-84 Transmission/Transfer Case
Circuit Description
The PCM energizes the converter clutch solenoid by creating a
ground path on CKT 924. When grounded (energized) by the
PCM, enable solenoid stops converter signal oil from exhaust-
ing. This causes converter signal oil pressure to increase and
shift the valve. The solenoid will de-energize when the PCM
no longer provides a ground path. When the solenoid is de-en-
ergized, it will exhaust fluid and release the TCC.This DTC de-
tects high torque converter slip when the clutch is engaged.
Conditions For Setting DTC
• No DTCs P0121, P0122, P0220, P0221, P0222, P0223,
P0225, P0226, P0227, or P0228.
• No DTC P0722, P0723.
• No DTCs P0716 or P0717.
• No DTCs P0742 or P1860.
• No DTC P1810.
• No DTC P1860.
• Converter clutch commanded on in 2nd or 3rd for more
than 0.6 seconds.
• Engine running for at least 5 seconds.
• Converter clutch applied for more than 0.6 seconds.
• Transmission in 2nd or 3rd.
• Throttle Position greater than 20%.
• Pressure switch in D4, D3, or D2.
• Transmission fluid temperature between -10° C (14° F)
and 150° C (302° F).
• Converter clutch slip speed is greater than 65 rpm for
4 seconds.
• All conditions must be met for a total of 2 occurrences.
Action Taken When DTC Sets
• PCM will inhibit converter clutch apply.
• PCM will inhibit 4th gear upshift.
• The PCM will illuminate the warning lamp.
Conditions For Clearing DTC
• The PCM will turn the warning light off after three con-
secutive ignition cycles without a failure reported. The
DTC can be cleared using the scan tool. The DTC will
clear 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 long enough to power down the
PCM.
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Diagnostic Aids
• Inspect the wiring for poor electrical at the PCM and the
transmission 20-way connector. Look for possible bent,
backed out, deformed or damaged terminals. Check for
weak terminal tension as well. Also, check for chafed
wire that could short to bare metal or other wiring In-
spect for broken wire inside the insulation.
• 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.
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