Hummer H1 (2002+). Manual - part 206

 

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 Electrical System  12-51

 

 

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05745159

 

IGNITION SWITCH REPLACEMENT

 

Removal

 

1.

Remove steering column covers.

2.

Remove multi switch.

3.

Remove screw and interlock cable from ignition switch
(Figure 2-76).

4.

Remove two capscrews and ignition switch from steering
column.

 

Installation

 

1.

Apply thread-locking compound to capscrew threads and 
install ignition switch on steering column with two cap-
screws.

2.

Install interlock cable on ignition switch with screw.

3.

Install multi switch.

4.

Install steering column covers.

5.

Ensure ignition switch operates properly.

 

Brake Shift Interlock Cable System Descrip-
tion (Figure 2-76)

 

The purpose of the brake shift interlock cable is to prevent a
driver from  engaging a transmission gear before the brakes are
applied. When the brake pedal is depressed, voltage from the
brake switch de-energizes the interlock solenoid and the cable
relaxes. The transmission shift lever can then be pulled out of
the park position. If electrical power is lost due to a dead bat-
tery or system failure, the solenoid defaults to the open posi-
tion. With the brake/shift interlock solenoid in the open
position the shifter may be moved to any position.

 

Figure 2-76:   Brake Shift Interlock Cable

SOLENOID

 

 Brake Shift Interlock Cable Inoperative

 

STEP

ACTION

VALUES

YES

NO

 

1

Gain access to the brake/shift interlock solenoid. 
Using a DVOM check for ground on the black 
wire (CKT 59). Does the resistance meet the    
specifications?

<.2 

 

Ω

 

Go to step 2.

Repair the open or 

bad connection in 

CKT 59 between 

the interlock sole-

noid and G4.

2

With the ignition switch in the “run” position 
check the voltage at the tan wire (CKT 83). Is the 
specified voltage present?

12v 

Go to step 3.

Repair the open or 

bad connection in 

CKT 83 between 

the interlock cable 

and fuse 1C in the 

interior fuse box.  

3

With the ignition switch in the “run” position and 
the brake switch applied check the voltage at the 
red wire (CKT 22) on the brake shift interlock 
solenoid. Is the specified voltage present?

12v

Replace the 

brake shift inter-

lock cable.

Go to step 4.

4

Gain access to the brake switch. With a DVOM 
check the voltage at the orange wire (CKT 10). Is 
the specified voltage present?

12v

Replace the 

brake switch.

Repair the open or 

bad connection on 

CKT 10 between 

the brake switch 

and fuse 4D.

 

3-1-01

 

12-52

Electrical System

 

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Figure 2-77:   Shift Interlock Cable Schematic

59 BK

FUSE

4D

15 AMP

INTERIOR

FUSE

BOX

INTERLOCK CABLE SOLENOID

83 TN

G4

TO

TURN SIGNAL

SWITCH

BRAKE
SWITCH

TO

BATTERY

22 RD

FUSE

1C

5 AMP

INTERIOR

FUSE

BOX

TO

IGNITION

9-S12-001

INTERIOR FUSE BOX

10 OR

 

4-1-00

 

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 Electrical System  12-53

 

 

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05745159

 

 CTIS Compressor Inoperative

 

Step

Action

Value(s)

Yes

No

 

1

Using a DVOM set to measure voltage, probe the 
terminals on the CTIS compressor. With the CTIS 
compressor switch set to inflate, and the ignition 
on, is voltage present?

12v

Replace the 

compressor

Go to step 2.

2

Move the ground lead to a known good ground 
and the positive lead still on the compressor, igni-
tion on, compressor switch on inflate. Is voltage 
present?

12v

Repair open or 

bad connection 

in CKT57 

between com-

pressor and G2.

Go to step 3.

3

Remove compressor relay from the exterior fuse 
box. Using a DVOM set to measure voltage, 
Probe cavity 1(CKT46) of the CTIS compressor 
relay socket with the positive lead, and cavity 
2(CKT59) with the negative lead. Ignition on, 
CTIS compressor switch to on, is voltage present?

12v

Go to step 7.

Go to step 4.

4

Using a DVOM set to measure voltage, check 
continuity to ground at cavity 2 of the compressor 
relay socket. Is resistance below specification?

<.2

 

Ω

 

Go to step 5.

Repair open or 

bad connection 

in CKT59 

between com-

pressor relay 

and G2.

5

Remove compressor switch from the dash. Using 
a DVOM set to measure voltage. Ignition on, 
compressor switch set to inflate. Check for volt-
age on white wire(CKT46). Is voltage present?

12v

Repair open or 

bad connection 

in CKT46 

between com-

pressor switch 

and relay.

Go to step 6.

6

Using a DVOM set to measure voltage, turn the 
ignition on. Check for voltage at both orange 
wires(CKT640) at the rear of the compressor 
switch. Is voltage present?

12v

Replace the 

compressor 

switch.

Repair open, 

bad connection 

or short in 

CKT640 

between com-

pressor switch 

and fuse 1G.

7

Using a DVOM set to measure continuity mea-
sure continuity between cavity 5(CKT437) of the 
compressor relay socket and the green 
wire(CKT437) at the compressor. Is resistance 
below specifications?

<.2

 

Ω

 

Go to step 8.

Repair open, 

bad connection, 

or short in 

CKT437 

between relay 

and compressor.

8

Using a DVOM set to measure voltage, place the 
positive lead in cavity 3 (CKT436) of the com-
pressor relay. Place the ground lead in cavity 
86(CKT59). Is voltage present?

<.2

 

Ω

 

Replace the 

compressor 

relay.

Repair open, 

bad connection 

or short in 

CKT436 

between com-

pressor relay 

and Maxi 

fuse#6.

 

4-1-00

 

12-54

Electrical System

 

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 CTIS Exhaust Valve Inoperative

 

Step

Action

Value(s)

Yes

No

 

1

Disconnect exhaust solenoid. Using a DVOM set 
to measure voltage, probe the light green 
wire(CKT47) with the positive lead, and the black 
wire(CKT57) with the negative lead. Ignition on, 
move the compressor switch to deflate. Is voltage 
present?

12v

Replace exhaust 

solenoid.

Go to step 2.

2

Check continuity to ground on the black 
wire(CKT57) at the exhaust solenoid. Is resis-
tance below specification?

<.2

 

Ω

 

Go to step 3.

Repair open or 

bad connection 

in CKT57 

between exhaust 

solenoid and 

G2.

3

Remove compressor switch. Using a DVOM set 
to measure voltage, check for voltage at both 
orange wires (CKT640). With ignition on is volt-
age present?

12v

Go to step 4.

Repair open, 

bad connection 

or short in 

CKT640 

between com-

pressor switch 

and fuse 1G.

4

Using a DVOM set to measure voltage, check for 
voltage at the light green wire(CKT47) with the 
ignition on and compressor switch to deflate. Is 
voltage present?

12v

Repair open bad 

connection or 

short in CKT 47 

between com-

pressor switch 

and exhaust 

solenoid.

Replace com-

pressor switch.

 

4-1-00