Hummer H1 Service Manual page 290

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DTC P0751 1-2 Shift Solenoid
Valve Performance
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 com-
binations.
This DTC detects incorrect Gear Ratios when a Gear is com-
manded. This is a type "A" DTC.
05745159
TORQUE
CONVERTER
PRESSURE
CLUTCH
CONTROL
SOLENOID
SOLENOID
(TCC)
(PCS)
D C
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
1-2 SHIFT
SOLENOID
(1-2)
2-3 SHIFT
SOLENOID
(2-3)
S B A
C32-D C32-C
C28-C6 C28-C4
2-3 SS 1-2 SS
CONTROL CONTROL
POWERTRAIN
CONTROL
MODULE
(PCM)
Conditions For Setting The DTC
• No DTCs P0121, P0122, P0123, P0220, P0221, P0222,
P0223, P0225, P0226, P0227 or P0228.
• No DTCs P0722 or P0723.
• No DTCs P0716 or P0717.
• No shift solenoid 1-2 DTC P0753.
• No shift solenoid 2-3 DTC P0758.
• No Pressure switch assembly DTC P1810.
• No Four Wheel Drive DTC P1875.
• Engine running.
• Vehicle speed is greater than 4.2 km/h (2.5 mph).
• Throttle angle is greater then 12%.
• Engine Torque between 60 ft/lbs and 450 ft/lbs.
• Transmission fluid temperature is greater than 20° C
(69° F).
• Engine Speed is less than 3650 RPM.
• Not in Four Wheel Drive Low.
TRANSMISSION
FLUID
TEMPERATURE
SENSOR
(TFT)
M L
C32-J C32-H
C29-B12 C27-C9
SENSOR TFT
GROUND SENSOR
SIGNAL
9 - S 1 2 - 0 6 7
5-91