Hummer H1 Service Manual page 271

5-72 Transmission/Transfer Case
Step
11
With the connector off of the VSS Buffer Module and
the key to the ON position, measure the voltage between
terminal 13 of the VSS Buffer Harness Connector and a
good ground.
Is the voltage within the specified value?
12 Is the voltage in Step 12 greater than the specified
value?
13 Inspect circuit 437 for an open or short to ground.
Did you find a problem?
14 Inspect circuit 437 for a short to power.
Did you find a problem?
15 1. Reconnect the VSS Buffer Harness connector to the
VSS Buffer Module.
2. With the DVOM set on DC volts and on a good
ground, back probe terminal 13 of the VSS Buffer
Module.
3. Start the engine, and place the transmission in D3.
4. With the wheels turning, slowly accelerate the
engine to 2000 RPM.
Is the voltage within the specified values?
16 Repair circuits 821 and 822. Refer to Repair Procedures,
Section 8.
Did you correct the problem?
17 Inspect the PCM for faulty or intermittent connections.
Did you find a problem?
18 Replace the OSS Sensor.
Is the replacement complete?
19 Replace the VSS Buffer Module.
Is the replacement complete?
20
Replace the PCM.
Is the replacement complete?
21 In order to verify your repair, perform the following pro-
cedure:
1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:
• Drive the vehicle under steady acceleration.
• The PCM must see an output speed of greater
than 500 RPM for 1 second.
4. Select Specific DTC. Enter DTC P0722.
Has the test run and passed?
DTC P0722 Output Speed Sensor Low Input (Cont'd)
Action
_____________________________________________
Value
4.8-5.2 volts
DC
5.2 volts DC
__
__
1.5-3.5 volts
DC
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—
—
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Yes No
Go to Step 15 Go to Step 12
Go to Step 14 Go to Step 13
Go to Step 21 Go to Step 17
Go to Step 21 Go to Step 17
Go to Step 17 Go to Step 19
Go to Step 21 —
Go to Step 21 Go to Step 20
Go to Step 21 —
Go to Step 21 —
Go to Step 21 —
Begin the
Diagnosis
again. Go to
System OK Step 1
®