Hummer H1 (2002+). Manual - part 297

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PCM/Tech 1 Scan Tool 121

®

05745159

.

DTC P1656 Wastegate Solenoid Control Circuit

Step

Action

Value(s)

Yes

No

1

Important

: Before clearing DTCs use the scan tool Capture Info 

Was the Powertrain On-Board Diagnostic (OBD) System Check perfom-
med?

—

Go to Step 2.

Go to OBD 

System Check.

2

1. Scan tool connected.
2. Ignition ON, engine OFF.

3. With scan tool, command Boost solenoid ON and OFF and listen for an

audible click.

Does the solenoid turn ON and OFF (audible click) with each command?

—

Go to Step 3.

Go to Step 5.

3

1. Ignition OFF.
2. Disconnect the PCM connector containing the Boost solenoid control

circuit.

3. Ignition ON.

4. Using DVM J–39200 on 10 Amp scale, measure current from the sole-

noid control circuit in the PCM harness connector to ground for 2 min-
utes.

Is current draw less then the specified value, but not zero?.

0.75A

Go to Step 8.

Go to Step 4.

4

1. Ignition OFF.
2. PCM connector still disconnected.

3. Disconnect Boost solenoid.

4. Using DVM J–39200, measure resistance from the solenoid control cir-

cuit in the PCM harness connector to ground.

Does DVM display infinite resistance?

—

Go to Step 

13.

Go to Step 10.

5

1. Disconnect Boost solenoid.
2. Ignition ON, engine OFF.

3. Connect a test light between the terminals at the harness connector.

4. Using a scan tool. command the solenoid ON and OFF.

Does test light turn ON and OFF with each command?

—

Go to Step 9.

Go to Step 6.

6

1. Ignition ON engine OFF.
2. With a test light connected to ground, probe the ignition feed circuit at

the Boost solenoid harness connector.

Is the test light ON?

—

Go to Step 7.

Go to Step 12.

7

1. Ignition OFF.
2. Reconnect solenoid.

3. Disconnect the PCM harness containing the solenoid control circuit.

4. Ignition ON.

5. With a fused jumper wire connected to ground, probe the solenoid con-

trol circuit in the PCM hamess connector.

Does the solenoid operate (audible click)?

—

Go to Step 

11.

Go to Step 10

8

DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic 
Aids. If additional DTCs were stored refer to the applicable DTC table(s) 
first.
Are any additional DTCs stored?

—

Go to the 

applicable 

DTC table

Go to Diag-

nostic Aids

122

PCM/Tech 1 Scan Tool

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®

9

Check for a poor connection at the Boost solenoid and replace temminals 
as necessary.
Did the terminals require replacement?

—

Go to Step 

15.

Go to Step 13

10

Repair Boost solenoid control circuit.
Is the action complete?

—

Go to Step 

15.

—

11

Check for a poor connection at the PCM, Boost solenoid control circuit.
Was a problem found?

—

Go to Step 

15.

Go to Step 14

12

Repair the open in the ignition feed circuit.
Is the action complete?

—

Go to Step 

15.

—

13

Replace the Boost solenoid. Refer to Wastegate Solenoid
Is the action complete?

—

Go to Step 

15.

—

14

Replace the PCM.
Important

: The new PCM must be programmed.

Refer to PCM Replacement/Programming.
Is the action complete?

—

Go to Step 

15.

—

15

1. Using the scan tool, select DTC, Clear Info.
2. Start engine and idle at nommal operating temperature.

3. Select DTC, Specific, then enter the DTC number which was set.

4. Operate vehicle until the Scan Tool indicates that the diagnostic Ran.

Does the scan tool indicate that this diagnostic Passed?

—

Go to Step 

15.

Go to Step 2

16

Using the scan tool, select Capture Info, Review Info.
Are any DTCs displayed that have not been diagnosed?

—

Go to the 

applicable 

DTC table

System OK

DTC P1656 Wastegate Solenoid Control Circuit

Step

Action

Value(s)

Yes

No

 

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PCM/Tech 1 Scan Tool 123

®

05745159

CONNECTOR LEGEND

76 WAY BULKHEAD

  

LOCATION: LEFT SIDE FIREWALL

PIN

CKT

COLOR

DESCRIPTION

1

400

LG

Ignition Feed +

2

739

PP

Left heated windshield power +

3

740

YL

Right heated windshield power +

4

43

DB

Trailer Brake activation 

5

962

BR

Trailer lights

6

33

WH

neutral safety switch feed

7

37E

YL

start relay feed

8

37D

YL

Ignition switch feed

9

786

RD

Fuel selector valve control

10

537

OR

Battery

C1 MALE

9-S12-048

PIN 1

PIN 12

PIN 13

PIN 26

PIN 27

PIN 38

PIN 50

PIN 64

PIN 76

PIN39

PIN 51

PIN 65

C1 FEMALE

9-S12-047

CAV 1

CAV 13

CAV 27

CAV 39

CAV 51

CAV 65

CAV 12

CAV 26

CAV 38

CAV 50

CAV 64

CAV 76

124

PCM/Tech 1 Scan Tool

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11

787

GY

Fuel pump + to selector valve

12

37

RD

Ignition relay feed

13

688

RD

Rear window defrost feed

14

723

YL

APP 3 5volt reference

15

724

DG

APP 3 signal

16

17

PP

+ From dimmer module

17

718

DB

APP 1 signal 

18

353

YL

Speedometer signal

19

607

TN

ABS module diagnostic line

20

717

WH

APP 1 5volt reference

21

961

PP

TT4 lamp activation

22

720

TN

APP 2 5volt reference

23

640

OR

IGN+ CTIS warning circuits

24

92

GY

CTIS rear inflate solenoid activation

25

714

DB

Check throttle lamp activation

26

37

RD

Battery feed to interior accessories

27

338

DB

Wait lamp activation

28

658

BR

Check engine lamp activation

29

151

GY

Cruise control ON/OFF signal

30

31

TN

Oil pressure signal

31

22

RD

Brake switch signal – rest

32

721

LB

APP 2 sensor signal

33

580

BR

Not Used for 99

34

606

OR

ABS diagnostic line

35

29

PK

Fuel gauge signal

36

39

DG

Engine temperature signal

37

153

LG

Cruise resume/accelerate signal

38

42

BR

Low brake fluid lamp activation

39

198

TN

A/C request

40

810

PP

TCC brake switch signal

41

2

LG

Right front turn signal

42

152

DB

Cruise set/coast signal

43

298

BR

Backup light switch feed

44

722

PP

APP 2 ground

45

327

YL

Water-in-fuel lamp activation

46

80

WH

Underhood lamp power

PIN

CKT

COLOR

DESCRIPTION