Hummer H1 Service Manual page 263

5-64 Transmission/Transfer Case
DTC P0716 Input Speed Sensor Circuit -
Range/Performance
Circuit Description
The Transmission input speed sensor consists of a permanent
magnet surrounded by a coil of wire. Current is induced in the
sensor by the forward clutch housing lugs which pass through
the sensor magnetic field. Signal voltage and frequency vary
directly with forward clutch rotational speed.
This DTC detects uncharacteristic changes in input speed.
Conditions for Setting DTC
• No TP DTC P0122, P0123, P0222, P0223, P0227, or
P0228.
• No DTC P0717.
• No DTC P0722 or P0723.
• No shift solenoid DTC P0751, P0753, P0756 or P0758.
• Throttle position is greater than 15%.
• Vehicle speed is greater than 20 MPH.
• Input speed varies by 1000 rpm within 2 seconds.
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.
Automatic
Transmission
Fluid
Pressure
Manual Valve
D2
Position
Switch
Switch
(TFP)
Lo
Switch
D4 D3
Switch Switch
D E
P R
C34
C32-S C32-H
C29-B5
C29-B4
Trans Trans
Range B
Range C
Input
Input
_____________________________________________
Auto Trans Input Shaft
Speed Sensor
A/T ISS
Rev
Switch
C
N
C32-K
Tw i s t e d
P a i r
C27-D1
C29-B6
Trans
Range A
Input
Conditions For Clearing DTC
• The PCM will turn the lamp off after three consecutive
ignition cycles without a failure reported.
• The DTC can be cleared from PCM memory using the
scan tool. The DTC can also be cleared from memory
after 40 warm-up cycles without a failure reported.
• The PCM will cancel the DTC Action Taken items
when the fault conditions no longer exist and the igni-
tion is cycled "Off"' long enough to power down the
PCM.
Diagnostic Aids
• Inspect the wiring for poor electrical connections at the
PCM and the transaxle 20-way connector. Look for pos-
sible bent, backed out, deformed or damaged terminals.
Check for weak terminal tension was well. Also, check
for chafed wire that could short to bear metal or other
wiring. Inspect for broken wire inside the insulation.
• 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 TPS codes are present diagnose
and clear these DTC(s) first. Then check to see if the
transmission DTC(s) have reset.
A
B
C32-A B
C27-D11
A / T ISS
A / T ISS
High Low
POWERTRAIN
CONTROL
MODULE
(PCM)
9-S12-071
®