Hummer H1 Service Manual page 1091

26 PCM/Tech 1 Scan Tool
DTC P0112 - Intake Air Temperature (IAT) Sensor Circuit Low Voltage
Step
1 NOTE: Before clearing DTC(s) use the Scan tool "Capture Info" to
record Freeze Frame and Failure Record for reference, as data will
be lost when "Clear Info" function is used.
Was the "On-Board Diagnostic (OBD) System Check" performed?
2 1. Scan tool connected.
2. Start the engine.
3. Monitor the IAT display on Scan Tool.
Is the IAT display greater than or equal to the specified value?
3 1. Turn the engine "OFF."
2. Turn the ignition "ON."
3. Disconnect the IAT sensor connector.
Is the IAT display less than or equal to the specified value?
4 1. Turn the ignition "OFF".
2. Using the J–39200, measure the resistance across the IAT sensor har-
ness connector.
Is the resistance at the specified value?
5 DCT is intermittent. If no additional DTCs are stored, refer to "Diagnostic
Aids." If additional DTCs were stored, refer to those table(s).
Are additional DTCs stored?
6 Repair the short to ground in the IAT signal circuit.
Is the action complete?
7 Replace the IAT sensor.
Is the action complete?
8 Replace the faulty PCM.
NOTE: If the PCM is faulty, the new PCM must be programmed.
Go to PCM replacement and programming procedures.
Is the action complete?
9 1. Using the Scan Tool, select "DTC," "Clear Info."
2. Start engine and idle at normal operating temperature.
3. Select "DTC," "Specific," then enter the DTC number which was set.
4. Operate vehicle within the conditions for setting this DTC as specified
in the supporting text.
Does the Scan Tool indicate that this diagnostic Ran and Passed?
10 Using the Scan Tool, select "Capture Info," "Review Info."
Are any DTC's displayed that have not been diagnosed?
_____________________________________________________
Action Value(s) Yes
— Go to Step 2 Go to OBD
151°C Go to Step 3 Go to Step 5
(303°F)
-30°C Go to Step 7 Go to Step 4
(-22°F)
Infinite Go to Step 8 Go to Step 6
— Go to the
applicable
DTC Table
— Go to Step 9
— Go to Step 9
— Go to Step 9
— Go to Step
10
— Go to the
applicable
DTC table
®
No
System Check
Go to
Diagnostic
Aids
—
—
—
Go to Step 2
System OK