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TROUBLE CODE DEFINITIONS GMC Yukon I

Automatic Transmission Diagnosis - 4L80-E: Diagnosis

TROUBLE CODE DEFINITIONS

Note. Only transmission-related trouble codes are listed. For engine-related DTCs, see appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section. Engine-related DTCs must be repaired first, as engine performance and related component signals will affect transmission operation and diagnosis.

Code No.Circuit Affected
12 (1)No RPM Reference Pulse
14Coolant Temp. Sensor Signal Voltage Low
15Coolant Temp. Sensor Signal Voltage High
21TPS Signal Voltage High
22TPS Signal Voltage Low
24Vehicle Speed Sensor Trans. Output Signal
28Trans. Range Pressure Switch
37/38TCC Brake Switch On/Off
39TCC Stuck Off
52/53System Voltage High
58Trans. Fluid Temp. High
59Trans. Fluid Temp. Low
68Transmission Component Slipping
69Torque Converter Clutch Stuck On
72VSS Circuit Loss Transmission Output Signal
73Pressure Control Solenoid
74Trans. Input Speed Error
75System Voltage Low
79Trans. Fluid Temp. High
812-3 Shift Solenoid Circuit Fault
821-2 Shift Solenoid Circuit Fault
83TCC PWM Solenoid Circuit Fault
85Undefined Gear Ratio
86Low Gear Ratio Error
87High Gear Ratio Error
(1) Display of a Code 12 is normal when no reference pulses are received by control module (engine not running).
(1)Display of a Code 12 is normal when no reference pulses are received by control module (engine not running).

PCM/TCM TROUBLE CODE DEFINITIONS