Equus 3123 - GM Code Reader (1982 - 1995) - Manual (Page 25)

Retrieving ECM Codes
GM 2-16
CODE SERVICE CODE DEFINITION
73 3rd line circuit - grounded or open
Coolant sensor signal unstable
74 Coolant/Transmission temperature sensor ratio error
3rd line circuit - shorted
75 3rd gear stuck "on"
Air temperature sensor signal
76 4th line circuit - grounded or open
Throttle position sensor (TPS) to manifold absolute
pressure (MAP) sensor voltage out of range
77 4th line circuit - shorted
78 4th gear stuck "on"
79 Torque Converter Clutch (TCC) circuit - grounded or
open
81 Torque Converter Clutch (TCC) circuit - shorted
82 Transaxle temperature unstable
83 Transaxle temperature low
Low coolant
84 Brake switch stuck open
85 Brake switch stuck closed
86 Engine speed invalid
87 Torque Converter Clutch (TCC) hold circuit - grounded
or open
88 Torque Converter Clutch (TCC) hold circuit - shorted
89 Master relay stuck "on"
91 Assembly Line Diagnostic Link (ALDL)
92 Clamp circuit - intermittent fault
93 Torque Converter Clutch (TCC) hold circuit -
intermittent fault
94 Master enable relay circuit intermittent fault
95 Line circuit - intermittent fault
96 Torque Converter Clutch (TCC) circuit - intermittent
fault
97 2nd gear circuit - intermittent fault
98 3rd gear circuit - intermittent fault
99 4th gear circuit - intermittent fault