Hummer H1 Service Manual page 1145

80 PCM/Tech 1 Scan Tool
DTC P0335 - Crankshaft Position Sensor Circuit Performance
Step
1 Important: Before clearing DTC(s) use the scan tool "Capture Info".
Was the "On-Board Diagnostic (OBD) System Check" performed?
2 Start and idle engine.
With throttle closed, observe "Crank Ref. Missed" display on scan tool. Does
scan tool display specified value?
3 DTC is intermittent. If no additional DTCs are stored, refer to "Diagnostic
Aids". If additional DTCs are stored, refer those table(s).
Are additional DTCs stored?
4 Ignition "OFF".
Disconnect the Optical/Fuel temperature sensor electrical connector.
Ignition "ON" engine "OFF".
Using a DVM (J–39200), measure voltage between the Optical/Fuel tempera-
ture 5 volt reference circuit and chassis ground.
Is voltage at specified value?
5 Probe sensor ground circuit with test light connected to B+. Is test light "ON"?
6 Reconnect the Optical/Fuel temperature sensor.
Back probe the Optical/Fuel temperature sensor signal circuit at the PCM with a
DVM (J–39200) connected to ground.
Crank engine.
Is voltage at the specified value?
7 Ignition "OFF".
Disconnect PCM and check Optical/Fuel Temp. 5 volt reference circuit for
open, short to ground, or short to sensor ground circuit.
If the Optical/Fuel temperature 5 volt reference circuit is open or shorted to
ground, repair as necessary.
Was the circuit open or shorted to ground?
8 Check for open or poor sensor ground terminal conn. at PCM.
If a problem is found, repair it. Was a repair performed?
9 Check the Optical/Fuel temperature 5 volt reference circuit for a poor connec-
tion at PCM and replace terminal if necessary.
Did the terminal require replacement?
10 Ignition "OFF".
Disconnect PCM and check Optical/Fuel temperature signal circuit for open,
short to ground, or short to sensor ground circuit.
If the Optical/Fuel temperature signal circuit is open or shorted to ground, re-
pair it. Was the Optical/Fuel temperature signal circuit open or shorted to
ground?
11 Check the Optical/Fuel temperature signal circuit for a poor connection at the
PCM and replace terminal if necessary.
Did the terminal require replacement?
12 Replace the Crankshaft position sensor. After replacing the sensor, the PCM
must be programmed with a new TDC OFFset . Refer to the Service Manual for
more information on the Crankshaft Position Sensor or reprogramming the
PCM.
Is the action complete?
13 Replace the faulty PCM. Notice: If the PCM is faulty, the new PCM must be
programmed. Is the action complete?
_____________________________________________________
Action Value(s) Yes
— Go to
Step 2.
8 Go to
Step 4.
— Go to the
applicable
DTC table.
4.8 - 5.2v Go to
Step 5.
— Go to
Step 6.
4v Go to
Step 11.
— Go to
Step 14.
— Go to
Step 14.
— Go to
Step 14.
— Go to
Step 14.
— Go to Step
14.
— Go to Step
14.
— Go to Step
14.
®
No
Go to OBD
System
Check.
Go to
Step 3.
Go to
Diagnostic
Aids.
Go to
Step 7.
Go to
Step 8.
Go to
Step 10.
Go to
Step 9.
Go to
Step 13.
Go to
Step 13.
Go to
Step 11.
Go to Step
12.
—
—