Genie GTH-636 Service Manual page 151

June 2007
REV A
How to Read the Fault Codes
The flashing BC light, when combined with short or
long pauses between the flash, tells the service
technician the specific fault coded detected by the
ECM, if any. Code 32, for example, would appear
as three quick flashes followed by a short pause of
two seconds, then two more quick flashes followed
by a long pause of four seconds. Code 33 would
appear as three quick flashes followed by a short
pause, then three more quick flashes followed by a
long pause.
Code and Description
11 Analog throttle input high
12 Analog throttle input low
18 Engine coolant temperature high
19 Engine coolant temperature low
21 Sensor supply voltage high
22 Sensor supply voltage low
23 Engine oil pressure input voltage high
24 Engine oil pressure input voltage low
25 Manifold air temperature input voltage high
26 Manifold air temperature input voltage low
28 ECM error
32 Signifies start of active fault codes
33 Signifies start of previously active fault codes
37 Fuel temperature input voltage high
38 Fuel temperature input voltage low
39 Crank position input noise/pattern error
42 Engine overspeed
54 ECM power down error
55 Can error
62 Engine coolant temperature high – least severe
Part No. 97487 GTH-636 • GTH-644 • GTH-842 • GTH-844 • GTH-1048 • GTH-1056
Example: If the ECM had no active faults to report,
though had stored codes 18 and 62 in memory, the
following flash sequence would be observed:
Three quick flashes followed by a short pause...
two quick flashes followed by a long pause... eight
quick flashes followed by a short pause... eight
quick flashes followed by a long pause... three
quick flashes followed by a short pause... three
quick flashes followed by a long pause... one quick
flash followed by a short pause... eight quick
flashes followed by a long pause... six quick
flashes followed by a short pause... two quick
flashes followed by a long pause... the ECM would
then repeat the previous sequence.
Code and Description
63 Engine coolant temp high – moderately severe
64 Engine oil pressure moderately low
65 Engine oil pressure extremely low
66 Manifold air temperature moderately high
68 Fuel derate
69 Engine coolant temperature high – most severe
71 Pump control valve closure too long
72 Pump control valve closure too short
73 Pump solenoid circuit open
74 Pump solenoid circuit severely shorted
75 Pump control valve closure not detected
76 Pump solenoid circuit moderately shorted
77 Pump solenoid current high
78 Security violation
79 Internal ECM error
81 Fuel temperature moderately high
82 Engine protection shutdown
83 Auxiliary engine shutdown switch active
84 ECM power down error/external derate active
88 Signifies that no fault codes are stored
Section 5 • Troubleshooting
TROUBLESHOOTING
5 - 3