Hummer H1 Service Manual page 292

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DTC P0753 1-2 Shift Solenoid Valve Electrical
Circuit Description
The 1-2 shift solenoid is used to control fluid acting on the 1-2 and
3-4 shift valves. The solenoid is a normally open valve used with
the 2-3 solenoid to allow four different shifting combinations. The
solenoid is attached to the control valve body. Ignition voltage is
supplied directly to the 1-2 shift solenoid. The PCM controls the
solenoid by providing a ground path through circuit 237.
This DTC detects a continuous open or short to ground in the 1-2
shift solenoid circuit or the 1-2 shift solenoid sensor.
Conditions For Setting DTC
• Ignition is on.
• The engine runs more then 475 RPM for greater than 7
seconds.
All conditions for running the DTC are met, and either of the
following conditions occur for 4.3 out of 5 seconds.
• The PCM commands the solenoid on, and the voltage
input remains high (B+).
• The PCM commands the solenoid off and the voltage
input remains low.
05745159
TORQUE
CONVERTER
PRESSURE
CLUTCH
CONTROL
SOLENOID
SOLENOID
(TCC)
(PCS)
D C S
C34
C32-F C32-E
C32-G
C27-C15 C27-C7 C28-C5
PCS PCS TCC PWM
LOW HIGH SOLENOID
CONTROL
Transmission/Transfer Case
HOT IN RUN
AND START
FUSE 2A
10A
EXTERIOR
C33-F
C34-E
TRANSMISSION
FLUID
TEMPERATURE
SENSOR
1-2 SHIFT
(TFT)
SOLENOID
(1-2)
2-3 SHIFT
SOLENOID
(2-3)
B A M
C32-D C32-C C32-J
C28-C6 C28-C4 C29-B12
2-3 SS 1-2 SS SENSOR
CONTROL CONTROL GROUND
POWERTRAIN
CONTROL
MODULE
(PCM)
Action Taken When DTC Sets
• The PCM will command maximum line pressure.
• The PCM will freeze shift adapts.
• The PCM will turn on the warning lamp.
• The PCM will store a DTC P0753 in the PCM history.
Conditions For Clearing DTC
• For California emissions, the PCM will turn the warning
lamp off after three consecutive 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 DTC default actions when the
fault no longer exists and the ignition is cycled "off"
long enough to power down the PCM.
L
C32-H
C27-C9
TFT
SENSOR
SIGNAL
9 - S 1 2 - 0 6 7
5-93
3-1-01