Diagnostic Trouble Code (DTC)

1994-1995 Trucks use 8192 Baud Data (OBDI). 

You can simply count flashes of the CEL/SES light on the dashboard after grounding Pin B with a jumper to a chassis ground or to Pin A and turning on the ignition key.  Each code is repeated 3 times (by the Service Engine Soon Light) in a morse code style fashion that we call the “blinkenlight routine”

For example:

<blink><blink> ...pause...<blink><blink><blink> = DTC 23

Here’s a great third party video on this from YouTube:

https://www.youtube.com/watch?v=5apIiJHU8Eo

DTC 12 - No Codes Present. If you only get this one, then there are no codes to worry about.

DTC 13 - Engine Shutoff Solenoid Circuit Fault (ESO)

DTC 14 - Engine Coolant Temperature (ECT) Sensor Circuit Low (High Temp)

DTC 15 - Engine Coolant Temperature (ECT) Sensor Circuit High (Low Temp)

DTC 16 - Vehicle Speed Sensor Buffer Fault (VSSB)

DTC 17 - High Resolution Circuit Fault ((Optic Sensor/Camshaft Sensor high resolution track)

DTC 18 - Pump Cam Reference Pulse Error (Optic Sensor/Camshaft Sensor low resolution track)

DTC 19 - Crankshaft Position Reference Error (CPS Crankshaft Position Sensor)

DTC 21 - Accelerator Pedal Position 1 Circuit High

DTC 22 - Accelerator Pedal Position 1 Circuit Low

DTC 23 - Accelerator Pedal Position 1 Circuit Range Fault

DTC 24 - Vehicle Speed Sensor Circuit Low (Output Speed Signal)

DTC 25 - Accelerator Pedal Position 2 Circuit High

DTC 26 - Accelerator Pedal Position 2 Circuit Low

DTC 27 - Accelerator Pedal Position 2 Circuit Range Fault

DTC 28 - Transmission Range Pressure Switch Circuit

DTC 29 - Glow Plug Relay Fault

DTC 31 - EGR Control Pressure/Baro Sensor Circuit Low (High Vacuum)

DTC 32 - EGR Circuit Error

DTC 33 - EGR Control Pressure/Baro Sensor Circuit High 

DTC 34 - Injection Timing Stepper Motor Fault -Injection pump or timing set fault

DTC 35 - Injection Pulse Width Error (Time Short) -PMD or Injection Pump fault (Closure Time)

DTC 36 - Injection Pulse Width Error (Time Long) -PMD or Injection Pump fault (Closure Time)

DTC 37 - TCC Brake Switch Stuck "ON"

DTC 38 - TCC Brake Switch Stuck "OFF"

DTC 39 - TCC Stuck "OFF"

DTC 41 - Brake Switch Circuit Fault

DTC 42 - Fuel Temperature Circuit Low (High Temp)

DTC 43 - Fuel Temperature Circuit High (Low Temp)

DTC 44 - EGR Pulse Width Error

DTC 45 - EGR Vent Error

DTC 46 - Malfunction Indicator Lamp (MIL) Circuit Fault

DTC 47 - Intake Air Temperature Sensor Circuit Low (High Temp)

DTC 48 - Intake Air Temperature Sensor Circuit High (Low Temp)

DTC 49 - Service Throttle Soon Lamp Circuit Fault

DTC 51 - PROM Error

DTC 52 - System Voltage High Long

DTC 53 - System Voltage High

DTC 54 - PCM fuel circuit error

DTC 55 - Sensor power supply 5V issue

DTC 56 - Injection Pump Calibration Resistor Error

DTC 57 - PCM 5 Volt Shorted

DTC 58 - Transmission Fluid Temp Circuit Low

DTC 59 - Transmission Fluid Temp Circuit High

DTC 61 - Turbo Boost Sensor Circuit High

DTC 62 - Turbo Boost Sensor Circuit Low

DTC 63 - Accelerator Pedal Position 3 Circuit High

DTC 64 - Accelerator Pedal Position 3 Circuit Low

DTC 65 - Accelerator Pedal Position 3 Circuit Range Fault

DTC 66 - 3-2 Shift Control Solenoid

DTC 67 - TCC Solenoid Circuit (Open or Short)

DTC 68 - Transmission Component Slipping, History Only Code

DTC 69 - TCC Stuck "ON"

DTC 71 - Set/Coast Switch Fault (Cruise Control)

DTC 72 - Vehicle Speed Sensor Circuit Loss (Output Speed Signal)

DTC 73 - Pressure Control Solenoid Circuit (Current Error)

DTC 74 - Transmission Input Speed (TIS) Sensor Circuit

DTC 75 - System Voltage Low

DTC 76 - Resume/Accel Switch Fault (Cruise Control)

DTC 77 - Not Used

DTC 78 - Turbo Wastegate Solenoid Fault

DTC 79 - Transmission Fluid Over Temperature

DTC 81 - Transmission 2-3 Shift Solenoid Circuit

DTC 82 - Transmission 1-2 Shift Solenoid Circuit

DTC 83 - Torque Converter Clutch

DTC 84 - APP circuit fault

DTC 85 - Transmission Gear

DTC 86 - Transmission Gear Ratio Error

DTC 87 - Transmission Gear Ratio Error

DTC 88 - Top Dead Center Offset Problem (TDCO out of range, move injection pump to spec)

DTC 89 - out of range shift time

DTC 91 - cylinder balance 1

DTC 92 - cylinder balance 2

DTC 93 - cylinder balance 3

DTC 94 - cylinder balance 4

DTC 95 - cylinder balance 5

DTC 96 - cylinder balance 6

DTC 97 - cylinder balance 7

DTC 98 - Cylinder Balance 8

DTC 99 - Accelerator Pedal Position Sensor 5-Volt Reference Problem

Image Reference : https://www.techedge.com.au/vehicle/aldl8192/8192hw.htm