Fault Code List - Hummer H1 Service Manual

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3. The start phase consists of the ABS warning light flashing
in the following sequence (Figure 7-45):
• Pause = 2.5 seconds (long)
• Flash = 2.5 seconds (long)
• Pause = 2.5 seconds (long)
• Flash = 0.5 seconds (short)
ABS
2.5 sec
Warning
Lamp
Figure 7-45: Blink Code Sequence For Start Phase.
ABS
2.5 sec 0.5 0.5
Warning
sec sec
Lamp
Figure 7-46: Blink Code Sequence For Code 3.3.
Fault Code List - Ignition key "OFF" to test system (except where noted)
Fault Code Problem Area
2-0 ECU internal
failure.
2-1 ECU internal
failure.
2-2 Recirculating
Pump (RCP)
operates contin-
uously.
2-2 RCP does not
operate.
2-4 RCP failure
(motor locked).
05745159
2.5 sec 2.5 sec 0.5
sec
8-S07-003
0.5 2.5 sec 0.5 0.5 0.5
sec sec sec sec
8-S07-004
Test Pin
Locations
-
-
11 and 27
30 and 27
9 and 11
27 and 30
9, 11 and 12
4. The first part of the code number (Figure 7-46:): A pause
of 2.5 seconds precedes a series of short flashes. Count the
flashes until the next long pause occurs. The number of
short flashes obtained is the first part of the code number.
5. The second part of the code number: A pause of 2.5
seconds occurs between the first and second parts, before a
series of short flashes occurs. The number of short flashes
forms the second part of the code number.
6. The sequence of the start phase , first and second parts
will continue until the switch jumper is deactivated.
NOTE: If you are unsure of the code, do not deactivate the
switch jumper from the DLC because the code for that fault
will be cleared from the memory.
7. The memory is capable of storing more than one fault. To
search the memory, reconnect the switch jumper and await
the next start phase.
8. Repeat the procedure until no further faults are stored in
the memory. The memory is cleared when a long pause of
7.5 seconds occurs after the start phase.
Clearing Fault Codes
At the end of a fault code cycle, deactivate the blink code
jumper. The fault code will cycle one more time before the
lamp remains on solid. Turn off the ignition and the fault code
will be cleared from memory.
The fault codes, their causes and repair actions are listed in the
following table.
Values
- Replace ECU.
- Replace ECU.
0 volts Check the RCP wiring, the pump relay and the
wiring connections. Repair or replace as required.
Ignition "ON" Check the RCP wiring, the pump relay and fuse
approximate and pump connections. Repair or replace as
battery + required.
voltage.
Ignition "ON" Excessive current failure. If pump does not run
motor running. with pins linked, replace modulator.
Brake System 7-35
Check/Repair
4-1-00