| DTC 13 (1) | Engine Shutoff Solenoid Circuit Fault |
| DTC 14 (1) | ECT Sensor Circuit Low (High Temperature Indicated) |
| DTC 15 (1) | ECT Sensor Circuit High (Low Temperature Indicated) |
| DTC 16 (1) | Vehicle Speed Sensor Buffer Fault |
| DTC 17 (1) | High Resolution Circuit Fault |
| DTC 18 (1) | Pump Cam Reference Pulse Error |
| DTC 19 (1) | Crankshaft Position Reference Error |
| DTC 21 (1) | APP No. 1 Circuit High (Models With PCM) |
| DTC 22 (1) | APP No. 1 Circuit Low (Models With PCM) |
| DTC 23 (1) | APP No. 1 Circuit Range Fault |
| DTC 24 (2) | VSS Circuit Low (Transmission Output Speed Signal) |
| DTC 25 (1) | Accelerator Pedal Position (APP) No. 2 Circuit High |
| DTC 26 (1) | Accelerator Pedal Position (APP) No. 2 Circuit Low |
| DTC 27 (1) | APP No. 2 Circuit Range Fault |
| DTC 28 (2) | Transmission Range Pressure Switch Circuit Fault |
| DTC 29 (1) | Glow Plug Relay Circuit Fault |
| DTC 31 (1) | EGR Control Pressure/Baro Sensor Ckt Low (High Vac) |
| DTC 32 (1) | EGR Circuit Error |
| DTC 33 (1) | EGR Control Pressure/Baro Sensor Ckt High (Low Vac) |
| DTC 34 (1) | Injection Timing Stepper (ITS) Motor Circuit Fault |
| DTC 35 (1) | Injection Pulse Width Error (Response Time Short) |
| DTC 36 (1) | Injection Pulse Width Error (Response Time Long) |
| DTCS 37/38 (2) | TCC Brake Switch Stuck On/Off |
| DTC 39 (2) | TCC Stuck Off (4L80-E) |
| DTC 41 (1) | Brake Switch Circuit Fault |
| DTC 42 (1) | Fuel Temp Circuit Low (High Temp Indicated) |
| DTC 43 (1) | Fuel Temp Circuit High (Low Temp Indicated) |
| DTC 44 (1) | EGR Pulse Width Error |
| DTC 45 (1) | EGR Vent Error |
| DTC 46 (1) | Malfunction Indicator Light (MIL) Circuit Fault |
| DTC 47 (1) | IAT Sensor Circuit Low (High Temperature Indicated) |
| DTC 48 (1) | IAT Sensor Circuit High (Low Temperature Indicated) |
| DTC 49 (1) | Service Throttle Soon Light Circuit Fault |
| DTC 51 (1) | PROM Problem (Faulty Or Incorrect PROM) |
| DTCS 52/53 (2) | System Voltage High Long |
| DTC 54 (1) | PCM Fuel Circuit Error |
| DTC 56 (1) | Injection Pump Calibration Resistor Error |
| DTC 57 (1) | PCM 5-Volt Shorted |
| DTC 58 (2) | Transmission Fluid Temp Sensor Circuit Low (High Temp Indicated) - 4L60-E & 4L80-E |
| DTC 59 (2) | Transmission Fluid Temp Sensor Circuit High (Low Temp Indicated) - 4L60-E & 4L80-E |
| DTC 61 (1) | Turbo Boost Sensor Circuit High |
| DTC 62 (1) | Turbo Boost Sensor Circuit Low |
| DTC 63 (1) | APP No. 3 Circuit High (Models With PCM) |
| DTC 64 (1) | APP No. 3 Circuit Low (Models With PCM) |
| DTC 65 (1) | APP NO. 3 Circuit Range Fault |
| DTC 66 (2) | 3-2 Control Solenoid Circuit Fault (4L60-E) |
| DTC 67 (2) | TCC Solenoid Circuit Fault (4L60-E) |
| DTC 68 (2) | Transmission Component Slipping (4L80-E) |
| DTC 69 (2) | TCC Stuck On (4L60-E) |
| DTC 69 (1) | TCC Stuck On (4L80-E) |
| DTC 71 (1) | Set/Coast Switch Fault (Models With PCM) |
| DTC 72 (2) | Speed Sensor Circuit Loss (Trans Output Speed Signal) - 4L60-E & 4L80-E |
| DTC 73 (2) | Pressure Control Solenoid Circuit (Current Error) |
| DTC 74 (2) | Transmission Input Speed Sensor Circuit (4L80-E) |
| DTC 75 (2) | System Voltage Low |
| DTC 76 (1) | Resume/Accel Switch Fault |
| DTC 78 (1) | Wastegate Solenoid Fault |
| DTC 79 (2) | Transmission Fluid Overtemp - 4L60-E & 4L80-E |
| DTC 81 (2) | 2-3 Shift Solenoid Circuit Fault - 4L60-E & 4L80-E |
| DTC 82 (2) | 1-2 Shift Solenoid Circuit Fault - 4L60-E & 4L80-E |
| DTC 83 (2) | TCC PWM Solenoid Circuit Fault - 4L60-E & 4L80-E |
| DTC 84 (1) | Accelerator Pedal Position (APP) Circuit Fault |
| DTC 85 (2) | Undefined Ratio Error (4L80-E) |
| DTC 86 (2) | Low Ratio Error (4L80-E) |
| DTC 87 (2) | High Ratio Error (4L80-E) |
| DTC 88 (1) | TDC Offset Error |
| DTC 91 (1) | Cylinder Balance Fault No. 1 Cylinder |
| DTC 92 (1) | Cylinder Balance Fault No. 2 Cylinder |
| DTC 93 (1) | Cylinder Balance Fault No. 3 Cylinder |
| DTC 94 (1) | Cylinder Balance Fault No. 4 Cylinder |
| DTC 95 (1) | Cylinder Balance Fault No. 5 Cylinder |
| DTC 96 (1) | Cylinder Balance Fault No. 6 Cylinder |
| DTC 97 (1) | Cylinder Balance Fault No. 7 Cylinder |
| DTC 98 (1) | Cylinder Balance Fault No. 8 Cylinder |
| DTC 99 (1) | APP No. 2 (5-Volt Reference Fault) |
| (1) Code is engine related. (2) Code is transmission related. |
