Hummer H1 Service Manual page 1077

12 PCM/Tech 1 Scan Tool
Engine Cranks But Will Not Start
Step
1 NOTE: Before clearing DTC(s) use the Scan Tool "Cap-
ture 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 Check for proper condition of batteries.
Is condition of batteries OK?
3 Check for adequate fuel in tank.
Is fuel at an adequate level?
4 Check the quality of fuel.
Is fuel quality OK?
5 Check glow plug system operation.
Are glow plugs operating OK?
6 Check for proper cranking speed.
Is cranking speed OK?
7 Check for a restriction in the fuel return system.
Does the fuel return system operate properly?
8 Check injection pump ground wire (located on top of the
injection pump).
Is ground OK?
9 Ignition "ON".
Does MIL come "ON"?
10 Install scan tool.
Does scan tool display data?
11 1. Loosen injector line at injector.
2. Crank engine.
3. Repeat for the remaining injectors.
Is there fuel coming out of injection line?
12 Disconnect Optical/Fuel temperature sensor.
Does vehicle start?
13 1. Reconnect Optical/Fuel temperature sensor.
2. Disconnect fuel solenoid driver.
3. With J–39200 connected to ground, probe fuel inject
control circuit at harness terminal (terminal A).
4. Crank engine.
Is voltage greater than or equal specified value?
14 1. Fuel solenoid driver still disconnected.
2. Jumper closure ground circuit (terminal C) with a test
light connected to B+ at the harness terminal.
Is test light "ON"?
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Action Value(s) Yes
— Go to Step 2
— Go to Step 3
— Go to Step 4
— Go to Step 5
— Go to Step 6
— Go to Step 7
— Go to Step 8
— Go to Step 9
Go to Step 10
— Go to Step 11
— Go to Step 17
— Go to Step 16
1.2v Go to Step 14
— Go to Step 15
®
No
Go to OBD System
Check
Go to Step 23
Go to Step 23
Go to Step 23
Go to Step 23
Go to Step 23
Go to Step 23
Go to Step 23
Go to "No Malfunc-
tion Indicator
Lamp" on page 8.
Go to "No Scan
Tool Data on
page 10.
Go to Step 12
Go to Step 13
Go to Step 18
Go to Step 19