Hummer H1 (2006+). Manual - part 362

12-124

Electrical System

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HEATED LEATHER SEATS

The vehicle may come equipped with front heated leather seats. The switch for the drivers seats is on the drivers side of the center
console (See Figure 12-82). When seated, the left side of the switch is the high setting, the right side is the low setting and the cen-
ter position is off. Passenger heated seat switch is located on the drivers side of the center console (See Figure 12-81). Service to
the seat heater is limited to switch replacement and module replacement. All other repairs must be performed in conjunction with
the heated seat kit. 

Figure 12-81:   Passengers Control Panel

2

With ignition on and radio on, check for 
voltage at RSA pin B5 (RSA enable sig-
nal). Is voltage present?

Approxi-

mate battery 

voltage.

Go to step 3.

Check/repair open circuit 
between RSA pin B5 and 

radio pin A3.

3

Check for continuity between radio pin 
A12 and ground. Is there continuity?

< 0.2 

1.

Go to step 5.

Repair circuit 59 between 

radio and ground point G4.

4

Check for continuity between radio pin 
A12 and RSA pin B6. Is there continuity?

< 0.2 

1.

Go to step 5.

Repair circuit 59 between 

radio and RSA.

5

With ignition on and RSA on, check for 
voltage at RSA pin A5 (RSA control sig-
nal). Is voltage present?

+ 5 VDC.

Replace RSA unit.

Go to step 6.

6

With ignition on and RSA on, check for 
voltage at radio pin B7 (RSA control sig-
nal). Is voltage present?

+ 5 VDC.

Go to step 7.

Check/repair open circuit 
between RSA pin A5 and 

radio pin B7.

7

Check for an open circuit between radio 
pin B8 and RSA pin A4 (left rear +). Is 
there continuity?

< 0.2 

1.

Go to step 8.

Check/repair open circuit 
between RSA pin A4 and 

radio pin B8.

8

Check for an open circuit between radio 
pin B9 and RSA pin A3 (left rear -). Is 
there continuity?

< 0.2 

1.

Go to step 9.

Check/repair open circuit 
between RSA pin A3 and 

radio pin B9.

9

Check for an open circuit between radio 
pin A11 and RSA pin A2 (right rear +). Is 
there continuity?

< 0.2 

1.

Go to step 10.

Check/repair open circuit 
between RSA pin A2 and 

radio pin B11.

10

Check for an open circuit between radio 
pin A18 and RSA pin A1 (right rear -). Is 
there continuity?

< 0.2 

1.

Go to step 1.

Check/repair open circuit 
between RSA pin A1 and 

radio pin A18.

CHART #6

STEP

ACTION

VALUE(S)

YES

NO

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 Electrical System  12-125

Figure 12-82:   Drivers Control Panel

 Seat Heater Does Not Heat  (Figures 12-139 and 12-140)

Step

Action

Value(S)

Yes

No

1

NOTE: The control box contains a timer
that will shut the heater off after one hour
of use. The switch must be cycled “OFF”
and “ON” to restart the heat cycle.

Turn ignition to the “ON” position. Posi-
tion the seat heater switch to one of the
heat positions. Does the switch illumi-
nate?

Switch light 
“ON”

Go to step 2.

 Check ckt 241 RD at 
the control box connec-
tor C9 for +12v and   If 
circuits OK and switch 
is not illuminated, 
replace the switch.

2

Cycle seat heater switch “OFF and
“ON”. Do you hear an audible click com-
ing from the control box?

Audible relay 
click.

Go to step 4.

Go to step 3.

3

Check switch output power at the 
control box connection. In high 
position check for voltage on the 
white wires. In low position check 
for voltage on the orange wires.

Approximate
battery + volt-
age.

Go to step 4.

Replace the switch.

4

Check resistance at terminals “A” and
“D” of 4 position cushion connector. Is
the resistance within specification?

3.2

1 +/-10%

(resistance of 
back and cushion 
element in series)

Go to step 6.

Go to step 5.

5

Isolate the back element and check its resis-
tance. Is the resistance within specifica-
tion?

1.2

1

+/- 10%

Replace the 
cushion element.

Replace the back ele-
ment.

6

Check resistance of NTC heat sensor in
the cushion element. Is the resistance
within specification?

10K

1

+/- 10% at 77° F

Replace the con-
trol box.

Replace cushion ele-
ment.

12-126

Electrical System

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NEUTRAL START BACK UP (NSBU) SWITCH 

The vehicle is equipped with a console style shift selector. In addition to the console shift selector provided for the operator, an-
other component associated with the shift selector is the neutral start back up (NSBU) switch mounted on the selector shaft of the
transmission. The NSBU switch transmits selector position information to the TCM. The NSBU switch mounts directly onto the
transmission housing from the outside and detects the angular position of the shift selector shaft. this position is communicated to
the TCM so that certain vehicle control functions can be coordinated with the position of the shift controls. The NSBU switch has
redundant circuitry to alert the TCM in the event of a single wire or switch failure. The neutral signal output of the NSBU switch is
used as confirmation that the transmission is in neutral before the engine starter is engaged. The NSBU switch is interfaced to the
starter circuit. The reverse signal is used for back up lights, auto dimming mirror defeat and may be used for back up warning de-
vices.

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 Electrical System  12-127

WIRING SCHEMATICS

ABS/TT4 POWER, GROUND AND WARNING LAMP CIRCUIT

Figure 12-83:   ABS/ TT4 Wiring Schematic