Content .. 240 241 242 243 ..

Hummer H1 (2006+). Manual - part 242

7-50

Brake System

_____________________________________________________________

4-0

Short circuit to
ground between
ECU and right
front inlet solenoid
valve.

6 and 27

5.0-7.5

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-1

Short circuit to
ground between
ECU and right
front outlet sole-
noid valve.

7 and 27

3.0-5.0

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-2

Short circuit to
ground between
ECU and left front
inlet solenoid valve.

23 and 27

5.0-7.5

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-3

Short circuit to
ground between
ECU and left front
outlet solenoid
valve.

24 and 27

3.0-5.0

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-4

Short circuit to
ground between
ECU and right rear
inlet solenoid valve.

4 and 27

5.0-7.5

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-5

Short circuit to
ground between
ECU and right rear
outlet solenoid
valve.

5 and 27

3.0-5.0

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-6

Short circuit to
ground between
ECU and left rear
inlet solenoid valve.

21 and 27

5.0-7.5

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-7

Short circuit to
ground between
ECU and left rear
outlet solenoid
valve.

22 and 27

3.0-5.0

Check electrical resistance of affected valve wir-
ing to ground at ECU connector and at modulator
assembly as necessary.

4-8

Short circuit to
ground between
ECU and RCP relay
1.

Remove Relay

11 or 30 and 27

Open circuit

Check wiring to pump relay and pump connector
through pump. Repair wiring or replace modula-
tor as necessary.

Fault Code List - Ignition key “OFF” to test system (except where noted)

Test pin locations refer to ABS Pinout Box J–35592

Fault Code

Problem Area

Test Pin

Locations

Values

Check/Repair

6-1-05

____________________________________________________________

Brake System 7-51

5745804

4-9

Short circuit to
ground between
ECU and RCP relay
2.

Remove Relay

12 and 27

Open circuit

Check wiring to pump relay and pump connector
through pump. Repair wiring or replace modula-
tor as necessary.

4-12

Right front wheel
speed sensor open
circuit.

17 and 34

500-2000

Check electrical resistance of affected sensor and
wiring at ECU connector and at harness plugs.
Repair wiring or replace sensor as necessary.

4-13

Left rear wheel
speed sensor open
circuit.

18 and 35

500-2000

Check electrical resistance of affected sensor and
wiring at ECU connector and at harness plugs.
Repair wiring or replace sensor as necessary.

4-14

Left front wheel
speed sensor open
circuit.

15 and 32

500-2000

Check electrical resistance of affected sensor and
wiring at ECU connector and at harness plugs.
Repair wiring or replace sensor as necessary.

4-15

Right rear wheel
speed sensor open
circuit.

16 and 33

500-2000

Check electrical resistance of affected sensor and
wiring at ECU connector and at harness plugs.
Repair wiring or replace sensor as necessary.

5-0

Short circuit to bat-
tery between ECU
and right front inlet
valve solenoid or
wiring.

6 and 27

0 volts

5.0-7.5

Check voltages at wiring harness including con-
nectors. Check electrical resistance of affected
valve wiring to ground at ECU connector and at
modulator assembly plug. Repair wiring or
replace as necessary.

5-1

Short circuit to bat-
tery between ECU
and right front out-
let valve solenoid or
wiring.

7 and 27

0 volts

3.0-5.0

5-2

Short circuit to bat-
tery between ECU
and left front inlet
valve solenoid or
wiring.

23 and 27

0 volts
5.0-7.5

5-3

Short circuit to bat-
tery between ECU
and left front outlet
valve solenoid or
wiring.

24 and 27

0 volts
3.0-5.0

5-4

Short circuit to bat-
tery between ECU
and right rear inlet
valve solenoid or
wiring.

4 and 27

0 volts
5.0-7.5

Fault Code List - Ignition key “OFF” to test system (except where noted)

Test pin locations refer to ABS Pinout Box J–35592

Fault Code

Problem Area

Test Pin

Locations

Values

Check/Repair

6-1-05

7-52

Brake System

_____________________________________________________________

5-5

Short circuit to bat-
tery between ECU
and right rear out-
let valve solenoid or
wiring.

5 and 27

0 volts
3.0-5.0

5-6

Short circuit to bat-
tery between ECU
and left rear inlet
valve solenoid or
wiring.

21 and 27

0 volts
5.0-7.5

5-7

Short circuit to bat-
tery between ECU
and left rear outlet
valve solenoid or
wiring.

22 and 27

0 volts
3.0-5.0

5-8

Short circuit to bat-
tery + between ECU
and RCP relay 1.

11 and 27

0 volts

Check wiring harness between ECU and relay and
pump ground connections. Repair wiring as nec-
essary.

5-9

Short circuit to bat-
tery + between ECU
and RCP relay 2.

12 and 27

0 volts

Check wiring harness between ECU and relay and
pump ground connections. Repair wiring as nec-
essary.

5-12

Right front wheel
speed signal is
erratic.

17 and 34

Greater than
0.9 volts AC
at one tire rev-
olution per
second.

Check for damaged tone wheel, incorrect sensor
adjustment, excessive tone wheel runnout (> .041"),
excessive geared hub input bearing play and tire size
mismatch. Repair or replace as necessary.

5-13

Left rear wheel
speed signal is
erratic.

18 and 35

Greater than
0.9 volts AC
at one tire rev-
olution per
second.

Check for damaged tone wheel, incorrect sensor
adjustment, excessive tone wheel runnout (> .041"),
excessive geared hub input bearing play and tire size
mismatch. Repair or replace as necessary.

5-14

Left front wheel
speed signal is
erratic.

15 and 32

Greater than
0.9 volts AC
at one tire rev-
olution per
second.

Check for damaged tone wheel, incorrect sensor
adjustment, excessive tone wheel runnout (> .041"),
excessive geared hub input bearing play and tire size
mismatch. Repair or replace as necessary.

5-15

Right rear wheel
speed signal is
erratic.

16 and 33

Greater than
0.9 volts AC
at one tire rev-
olution per
second

Check for damaged tone wheel, incorrect sensor
adjustment, excessive tone wheel runnout (> .041"),
excessive geared hub input bearing play and tire size
mismatch. Repair or replace as necessary.

Fault Code List - Ignition key “OFF” to test system (except where noted)

Test pin locations refer to ABS Pinout Box J–35592

Fault Code

Problem Area

Test Pin

Locations

Values

Check/Repair

6-1-05

____________________________________________________________

Brake System 7-53

5745804

6-0

Short circuit
between two sole-
noid valve leads of
right front inlet
solenoid valve.

6 and 4, 5, 7,
21, 22, 23, 24

6.0-15.0

Check electrical resistance of affected valves and
wiring at ECU connector and at modulator assem-
bly plug. Repair or replace wiring as necessary
and replace modulator if short is internal.
Note: Fault code for both affected valves will be
stored in memory.

6-1

Short circuit
between two sole-
noid valve leads of
right front outlet
solenoid valve.

7 and 4, 5, 6,
21, 22, 23, 24

6.0-15.0

6-2

Short circuit
between two sole-
noid valve leads of
left front inlet sole-
noid valve.

23 and 4, 5, 6,
7, 21, 22, 24

6.0-15.0

6-3

Short circuit
between two sole-
noid valve leads of
right front outlet
solenoid valve.

24 and 4, 5, 6,
7, 21, 22, 23

6.0-15.0

6-4

Short circuit
between two sole-
noid valve leads of
right rear inlet
solenoid valve.

4 and 5, 6, 7,
21, 22, 23, 24

6.0-15.0

6-5

Short circuit
between two sole-
noid valve leads of
right rear outlet
solenoid valve.

5 and 4, 6, 7,
21, 22, 23, 24

6.0-15.0

6-6

Short circuit
between two sole-
noid valve leads of
left rear inlet sole-
noid valve.

21 and 4, 5, 6,
7, 22, 23, 24

6.0-15.0

Fault Code List - Ignition key “OFF” to test system (except where noted)

Test pin locations refer to ABS Pinout Box J–35592

Fault Code

Problem Area

Test Pin

Locations

Values

Check/Repair

6-1-05

Content .. 240 241 242 243 ..