Hummer H1 (2002+). Manual - part 269

 

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PCM/Tech 1 Scan Tool 9

 

 

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05745159

14

Locate and repair short to ground in the status center 
Ignition Feed circuit.
Is the action complete?

 

—

 

Go to Step 20

 

—

 

15

Replace the PCM. 
NOTE: If the PCM is faulty, then PCM must be pro-
grammed. Go to PCM Replacement and Programming 
Procedures.
Is the action complete?

 

—

 

Go to Step 20

 

—

 

16

1. Check the MIL control circuit for a poor connection at

the status center connector.

2. If a problem is found, repair as necessary.

Was a problem found?

 

—

 

Go to Step 20

Go to Step 17

17

1. Remove the status center.
2. Inspect the MIL bulb.

Is the bulb OK?

 

—

 

Go to Step 19

Go to Step 18

18

Replace the MIL bulb.
Is the action complete?

 

—

 

Go to Step 20

 

—

 

19

Replace the status center.
Is the action complete?

 

—

 

Go to Step 20

 

—

 

20

1. Using the Scan Tool, select “DTC,” “Clear Info.”
2. Attempt to start the engine.

Does the engine start and continue to run?

 

—

 

Go to Step 21

Go to Step 2

21

1. Allow engine to idle until normal operating tempera-

ture is reached.

2. Select “DTC,” “Failed This Ign.”

Are any DTCs displayed?

 

—

 

Go to Applicable 
DTC Table

Go to Step 22

22

Using the Scan Tool, select “Capture Info,” “Review 
Info.”
Are any DTCs displayed that have not been diagnosed?

 

—

 

Go to Applicable 
DTC Table

System OK

 

 No Malfunction Indicator Lamp (MIL) “Check Engine”

 

Step

Action

Value(s)

Yes

No

 

10

PCM/Tech 1 Scan Tool

 

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 No Scan Tool Data

 

Step

Action

Value(s)

Yes

No

 

1

Was the “On-Board Diagnostic (OBD) System Check” 
performed?

—

Go to Step 2

Go to OBD System 
Check

2

1. Ignition “OFF” for 30 seconds.
2. Ignition “ON,” Engine “OFF.”

Is the MIL “ON”?

—

Go to Step 3

Go to Chart A-1

3

Can the Scan Tool communicate with the PCM?

—

Go to Step 4

Go to Step 7

4

With the Scan Tool, command the MIL “ON” and “OFF.”

—

Go to Step 17

Go to Step 5

5

1. Ignition “OFF.”
2. Disconnect the PCM connectors.

3. Ignition “ON.”

Is the MIL “OFF”?

—

Go to Step 6

Go to Step 18

6

With the Scan Tool, check Engine Cal ID.
Is the proper CAL ID present?

—

Go to Step 28

Go to Step 19

7

With a test light to ground, probe the DLC connector (pin 
16).
Is the test light “ON”?

—

Go to Step 8

Go to Step 20

8

With a test light to B+, probe the DLC connector (pins 4 
and 5).
Is the test light “ON” for both circuits?

—

Go to Step 9

Go to Step 21

9

Check for proper operation of the cigar lighter.
Does the cigar lighter operate properly?

—

Go to Step 10

Go to Step 22

10

Verify proper operation of the Scan Tool with a known 
good vehicle with the same equipment/controller.
Does the Scan Tool communicate with known good vehi-
cle?

—

Go to Step 11

Go to Step 23

11

1. Disconnect the Scan Tool.
2. With the DVM connected to ground, check the PCM

serial data line at the DLC connector (pin 2).

Is voltage on the serial data line less than the specified
value?

7v

Go to Step 12

Go to Step 15

12

With the DVM connected to ground, again check the 
PCM serial data line at the DLC connector (pin 2).
Is voltage on the serial data line less than the specified 
value?

1v

Go to Step 13

Go to Step 16

13

1. Ignition “OFF.”
2. With the DVM connected to ground, check resistance

of the serial data line at the DLC connector (pin 2).

Is resistance less than the specified value?

10 Ohms

Go to Step 14

Go to Step 27

14

1. Disconnect the PCM connectors.
2. With the DVM connected to ground check resistance

of the serial data line at the DLC connector (pin 2).

Is resistance less than the specified value?

10 Ohms

Go to Step 24

Go to Step 28

 

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PCM/Tech 1 Scan Tool 11

 

 

®

 

05745159

15

1. Ignition “OFF.”
2. Disconnect the PCM Connectors.

3. Ignition “ON.”

4. Check voltage on the DLC connector (pin 2).

Is voltage at the specified value?

0v

Go to Step 28

Go to Step 25

16

Reprogram the EEPROM and retest.
Is serial data present?

—

Go to Step 26

Go to Step 28

17

System OK.

—

—

—

18

Repair short to ground on the MIL control circuit.

—

—

—

19

Reprogram the EEPROM and retest.

—

—

—

20

1. Check fuse number 7.
2. If fuse is blown, repair short to ground in the battery

feed circuit to the DLC connector (pin 16).

3. If the fuse is OK, repair open in the battery feed circuit

to the DLC connector (pin 16).

—

—

—

21

Repair open in circuit that did not light the test light.
Refer to Section 12 for ground distribution.

—

—

—

22

Refer to Section 12 for cigar lighter repair.

—

—

—

23

Faulty Scan Tool and/or cable.

—

—

—

24

Repair short to ground in the serial data line.

—

—

—

25

Repair short to voltage in the serial data line.

—

—

—

26

System OK.

—

—

—

27

1. Check serial data line for an open.
2. If OK, check PCM and DLC connections.

3. If OK, replace the PCM.

 

NOTE:

 

 If the PCM is faulty, the new PCM must be

programmed. Go to PCM replacement and pro-
gramming procedures.

 

Is the action complete?

—

Go to OBD 
System Check

—

28

Replace the faulty PCM.

 

NOTE:

 

 if the PCM is faulty, the new PCM must be

programmed. Go the PCM replacement and pro-
gramming procedures.

 

Is the action complete?

—

Go to OBD 
System Check

—

 

 No Scan Tool Data

 

Step

Action

Value(s)

Yes

No

 

12

PCM/Tech 1 Scan Tool

 

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 Engine Cranks But Will Not Start

 

Step

Action

Value(s)

Yes

No

 

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?

—

Go to Step 2

Go to OBD System 
Check

2

Check for proper condition of batteries. 
Is condition of batteries OK?

—

Go to Step 3

Go to Step 23

3

Check for adequate fuel in tank.
Is fuel at an adequate level?

—

Go to Step 4

Go to Step 23

4

Check the quality of fuel.
Is fuel quality OK?

—

Go to Step 5

Go to Step 23

5

Check glow plug system operation.

Are glow plugs operating OK?

—

Go to Step 6

Go to Step 23

6

Check for proper cranking speed.
Is cranking speed OK?

—

Go to Step 7

Go to Step 23

7

Check for a restriction in the fuel return system.
Does the fuel return system operate properly?

—

Go to Step 8

Go to Step 23

8

Check injection pump ground wire (located on top of the 
injection pump).
Is ground OK?

—

Go to Step 9

Go to Step 23

9

Ignition “ON”.
Does MIL come “ON”?

Go to Step 10

Go to “No Malfunc-
tion Indicator 
Lamp” on page 8.

10

Install scan tool.
Does scan tool display data?

—

Go to Step 11

Go to “No Scan 

Tool Data on 
page 10.

11

1. Loosen injector line at injector.
2. Crank engine.

3. Repeat for the remaining injectors.

Is there fuel coming out of injection line?

—

Go to Step 17

Go to Step 12

12

Disconnect Optical/Fuel temperature sensor.

Does vehicle start?

—

Go to Step 16

Go to Step 13

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?

1.2v

Go to Step 14

Go to Step 18

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”?

—

Go to Step 15

Go to Step 19