P26xx codes: Computer (engine control module) and output circuits
256 powertrain trouble codes from P2600 to P26FF. They mostly involve the wiring harness, control module, solenoid and oil control valve.
All P26xx codes
221 of these codes usually turn on the check engine light; 65 can often be fixed at home.
| Code | Meaning | Difficulty |
|---|---|---|
| P2600 | Coolant Pump A Control Circuit/Open | Medium |
| P2601 | Coolant Pump A Control Circuit Performance/Stuck Off | Medium |
| P2602 | Coolant Pump A Control Circuit Low | Medium |
| P2603 | Coolant Pump A Control Circuit High | Medium |
| P2604 | Intake Air Heater A Circuit Range/Performance | Medium |
| P2605 | Intake Air Heater B Circuit/Open | Medium |
| P2606 | Intake Air Heater B Circuit Range/Performance | Medium |
| P2607 | Intake Air Heater B Circuit Low | Medium |
| P2608 | Intake Air Heater B Circuit High | Medium |
| P2609 | Intake Air Heater System Performance | Medium |
| P260A | PTO Control Circuit/Open | Medium |
| P260B | PTO Control Circuit Low | Medium |
| P260C | PTO Control Circuit High | Medium |
| P260D | PTO Engaged Lamp Control Circuit | Easy |
| P260E | Particulate Filter Regeneration Lamp Control Circuit | Medium |
| P260F | EVAP System Monitoring Processor Performance | Medium |
| P2610 | ECM/PCM Internal Engine Off Timer Performance | Workshop only |
| P2611 | A/C Refrigerant Distribution Valve A Control Circuit/Open | Medium |
| P2612 | A/C Refrigerant Distribution Valve A Control Circuit Low | Medium |
| P2613 | A/C Refrigerant Distribution Valve A Control Circuit High | Medium |
| P2614 | Camshaft A Position Signal Output Circuit/Open (Bank 1) | Medium |
| P2615 | Camshaft A Position Signal Output Circuit Low (Bank 1) | Medium |
| P2616 | Camshaft A Position Signal Output Circuit High (Bank 1) | Medium |
| P2617 | Crankshaft Position Signal Output Circuit/Open | Medium |
| P2618 | Crankshaft Position Signal Output Circuit Low | Medium |
| P2619 | Crankshaft Position Signal Output Circuit High | Medium |
| P261A | Coolant Pump B Control Circuit/Open | Medium |
| P261B | Coolant Pump B Control Circuit Performance/Stuck Off | Medium |
| P261C | Coolant Pump B Control Circuit Low | Medium |
| P261D | Coolant Pump B Control Circuit High | Medium |
| P261E | Coolant Pump B Control Circuit Stuck On | Medium |
| P261F | Coolant Pump A Control Circuit Stuck On | Medium |
| P2620 | Throttle Position Output Circuit/Open | Medium |
| P2621 | Throttle Position Output Circuit Low | Medium |
| P2622 | Throttle Position Output Circuit High | Medium |
| P2623 | Injector Control Pressure Regulator Circuit/Open | Hard |
| P2624 | Injector Control Pressure Regulator Circuit Low | Hard |
| P2625 | Injector Control Pressure Regulator Circuit High | Hard |
| P2626 | O2 Sensor Pumping Current Trim Circuit/Open (Bank 1 Sensor 1) | Medium |
| P2627 | O2 Sensor Pumping Current Trim Circuit Low (Bank 1 Sensor 1) | Medium |
| P2628 | O2 Sensor Pumping Current Trim Circuit High (Bank 1 Sensor 1) | Medium |
| P2629 | O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 1) | Medium |
| P262A | Fuel Injector - Pilot Injection Not Learned | Hard |
| P262B | Control Module Power Off Timer Performance | Workshop only |
| P262C | Sensor Reference Voltage G Circuit/Open | Medium |
| P262D | Sensor Reference Voltage G Circuit Low | Medium |
| P262E | Sensor Reference Voltage G Circuit High | Medium |
| P262F | Sensor Reference Voltage G Circuit Range/Performance | Medium |
| P2630 | O2 Sensor Pumping Current Trim Circuit Low (Bank 2 Sensor 1) | Medium |
| P2631 | O2 Sensor Pumping Current Trim Circuit High (Bank 2 Sensor 1) | Medium |
| P2632 | Fuel Pump B Control Circuit/Open | Medium |
| P2633 | Fuel Pump B Control Circuit Low | Medium |
| P2634 | Fuel Pump B Control Circuit High | Medium |
| P2635 | Fuel Pump A Low Flow/Performance | Medium |
| P2636 | Fuel Pump B Low Flow/Performance | Medium |
| P2637 | Torque Management Feedback Signal A | Workshop only |
| P2638 | Torque Management Feedback Signal A Range/Performance | Workshop only |
| P2639 | Torque Management Feedback Signal A Low | Workshop only |
| P263A | MIL Control Circuit Low | Medium |
| P263B | MIL Control Circuit High | Medium |
| P263C | Glow Plug Control Driver Performance | Medium |
| P263D | Reductant Heater Driver Performance | Hard |
| P263E | Glow Plug Control Module 1 Over Temperature | Medium |
| P263F | Glow Plug Control Module 2 Over Temperature | Medium |
| P2640 | Torque Management Feedback Signal A High | Workshop only |
| P2641 | Torque Management Feedback Signal B | Workshop only |
| P2642 | Torque Management Feedback Signal B Range/Performance | Workshop only |
| P2643 | Torque Management Feedback Signal B Low | Workshop only |
| P2644 | Torque Management Feedback Signal B High | Workshop only |
| P2645 | "A" Rocker Arm Actuator Control Circuit/Open (Bank 1) | Medium |
| P2646 | "A" Rocker Arm Actuator System Performance/Stuck Off (Bank 1) | Medium |
| P2647 | "A" Rocker Arm Actuator System Stuck On (Bank 1) | Medium |
| P2648 | "A" Rocker Arm Actuator Control Circuit Low (Bank 1) | Medium |
| P2649 | "A" Rocker Arm Actuator Control Circuit High (Bank 1) | Medium |
| P264A | "A" Rocker Arm Actuator Position Sensor Circuit (Bank 1) | Hard |
| P264B | "A" Rocker Arm Actuator Position Sensor Circuit Range/Performance (Bank 1) | Hard |
| P264C | "A" Rocker Arm Actuator Position Sensor Circuit Low (Bank 1) | Hard |
| P264D | "A" Rocker Arm Actuator Position Sensor Circuit High (Bank 1) | Hard |
| P264E | "A" Rocker Arm Actuator Position Sensor Circuit Intermittent/Erratic (Bank 1) | Hard |
| P264F | Engine Serial Number Not Programmed or Incompatible | Workshop only |
| P2650 | "B" Rocker Arm Actuator Control Circuit/Open (Bank 1) | Medium |
| P2651 | "B" Rocker Arm Actuator System Performance/Stuck Off (Bank 1) | Medium |
| P2652 | "B" Rocker Arm Actuator System Stuck On (Bank 1) | Medium |
| P2653 | "B" Rocker Arm Actuator Control Circuit Low (Bank 1) | Medium |
| P2654 | "B" Rocker Arm Actuator Control Circuit High (Bank 1) | Medium |
| P2655 | "A" Rocker Arm Actuator Control Circuit/Open (Bank 2) | Medium |
| P2656 | "A" Rocker Arm Actuator System Performance/Stuck Off (Bank 2) | Medium |
| P2657 | "A" Rocker Arm Actuator System Stuck On (Bank 2) | Medium |
| P2658 | "A" Rocker Arm Actuator Control Circuit Low (Bank 2) | Medium |
| P2659 | "A" Rocker Arm Actuator Control Circuit High (Bank 2) | Medium |
| P265A | "B" Rocker Arm Actuator Position Sensor Circuit (Bank 1) | Hard |
| P265B | "B" Rocker Arm Actuator Position Sensor Circuit Range/Performance (Bank 1) | Hard |
| P265C | "B" Rocker Arm Actuator Position Sensor Circuit Low (Bank 1) | Hard |
| P265D | "B" Rocker Arm Actuator Position Sensor Circuit High (Bank 1) | Hard |
| P265E | "B" Rocker Arm Actuator Position Sensor Circuit Intermittent/Erratic (Bank 1) | Hard |
| P265F | Variable A/C Compressor Control Circuit Range/Performance | Medium |
| P2660 | "B" Rocker Arm Actuator Control Circuit/Open (Bank 2) | Medium |
| P2661 | "B" Rocker Arm Actuator System Performance/Stuck Off (Bank 2) | Medium |
| P2662 | "B" Rocker Arm Actuator System Stuck On (Bank 2) | Medium |
| P2663 | "B" Rocker Arm Actuator Control Circuit Low (Bank 2) | Medium |
| P2664 | "B" Rocker Arm Actuator Control Circuit High (Bank 2) | Medium |
| P2665 | Fuel Shutoff Valve B Control Circuit/Open | Medium |
| P2666 | Fuel Shutoff Valve B Control Circuit Low | Medium |
| P2667 | Fuel Shutoff Valve B Control Circuit High | Medium |
| P2668 | Fuel Mode Indicator Lamp Control Circuit | Easy |
| P2669 | Actuator Supply Voltage B Circuit/Open | Hard |
| P266A | "A" Rocker Arm Actuator Position Sensor Circuit (Bank 2) | Hard |
| P266B | "A" Rocker Arm Actuator Position Sensor Circuit Range/Performance (Bank 2) | Hard |
| P266C | "A" Rocker Arm Actuator Position Sensor Circuit Low (Bank 2) | Hard |
| P266D | "A" Rocker Arm Actuator Position Sensor Circuit High (Bank 2) | Hard |
| P266E | "A" Rocker Arm Actuator Position Sensor Circuit Intermittent/Erratic (Bank 2) | Hard |
| P266F | A/C Refrigerant Distribution Valve A Control Circuit Driver Current/Temperature Too High | Medium |
| P2670 | Actuator Supply Voltage B Circuit Low | Hard |
| P2671 | Actuator Supply Voltage B Circuit High | Hard |
| P2672 | Injection Pump Timing Offset | Hard |
| P2673 | Injection Pump Timing Calibration Not Learned | Medium |
| P2674 | Injection Pump Fuel Calibration Not Learned | Medium |
| P2675 | Air Cleaner Inlet Control Circuit/Open | Easy |
| P2676 | Air Cleaner Inlet Control Circuit Low | Easy |
| P2677 | Air Cleaner Inlet Control Circuit High | Easy |
| P2678 | Coolant Degassing Valve Control Circuit/Open | Medium |
| P2679 | Coolant Degassing Valve Control Circuit Low | Medium |
| P267A | "B" Rocker Arm Actuator Position Sensor Circuit (Bank 2) | Hard |
| P267B | "B" Rocker Arm Actuator Position Sensor Circuit Range/Performance (Bank 2) | Hard |
| P267C | "B" Rocker Arm Actuator Position Sensor Circuit Low (Bank 2) | Hard |
| P267D | "B" Rocker Arm Actuator Position Sensor Circuit High (Bank 2) | Hard |
| P267E | "B" Rocker Arm Actuator Position Sensor Circuit Intermittent/Erratic (Bank 2) | Hard |
| P267F | Control Module Internal Temperature Sensor A Circuit Intermittent/Erratic | Hard |
| P2680 | Coolant Degassing Valve Control Circuit High | Medium |
| P2681 | Engine Coolant Bypass Valve A Control Circuit/Open | Medium |
| P2682 | Engine Coolant Bypass Valve A Control Circuit Low | Medium |
| P2683 | Engine Coolant Bypass Valve A Control Circuit High | Medium |
| P2684 | Actuator Supply Voltage C Circuit/Open | Hard |
| P2685 | Actuator Supply Voltage C Circuit Low | Hard |
| P2686 | Actuator Supply Voltage C Circuit High | Hard |
| P2687 | Fuel Supply Heater Control Circuit/Open | Medium |
| P2688 | Fuel Supply Heater Control Circuit Low | Medium |
| P2689 | Fuel Supply Heater Control Circuit High | Medium |
| P268A | Fuel Injector Calibration Not Learned/Programmed | Medium |
| P268B | High Pressure Fuel Pump Calibration Not Learned/Programmed | Medium |
| P268C | Cylinder 1 Injector Data Incompatible | Medium |
| P268D | Cylinder 2 Injector Data Incompatible | Medium |
| P268E | Cylinder 3 Injector Data Incompatible | Medium |
| P268F | Cylinder 4 Injector Data Incompatible | Medium |
| P2690 | Cylinder 5 Injector Data Incompatible | Medium |
| P2691 | Cylinder 6 Injector Data Incompatible | Medium |
| P2692 | Cylinder 7 Injector Data Incompatible | Medium |
| P2693 | Cylinder 8 Injector Data Incompatible | Medium |
| P2694 | Cylinder 9 Injector Data Incompatible | Medium |
| P2695 | Cylinder 10 Injector Data Incompatible | Medium |
| P2696 | Injector Data Incompatible | Medium |
| P2697 | Exhaust Aftertreatment Fuel Injector A Circuit/Open | Medium |
| P2698 | Exhaust Aftertreatment Fuel Injector A Performance | Hard |
| P2699 | Exhaust Aftertreatment Fuel Injector A Circuit Low | Medium |
| P269A | Exhaust Aftertreatment Fuel Injector A Circuit High | Medium |
| P269B | Exhaust Aftertreatment Glow Plug Control Circuit/Open | Medium |
| P269C | Exhaust Aftertreatment Glow Plug Control Performance | Medium |
| P269D | Exhaust Aftertreatment Glow Plug Control Circuit Low | Medium |
| P269E | Exhaust Aftertreatment Glow Plug Control Circuit High | Medium |
| P269F | Exhaust Aftertreatment Glow Plug Circuit/Open | Medium |
| P26A0 | Exhaust Aftertreatment Glow Plug Performance | Medium |
| P26A1 | Exhaust Aftertreatment Glow Plug Circuit Low | Medium |
| P26A2 | Exhaust Aftertreatment Glow Plug Circuit High | Medium |
| P26A3 | Engine Coolant Bypass Valve A Range/Performance | Medium |
| P26A4 | Engine Coolant Bypass Valve A Position Sensor Circuit | Medium |
| P26A5 | Engine Coolant Bypass Valve A Position Sensor Circuit Range/Performance | Medium |
| P26A6 | Engine Coolant Bypass Valve A Position Sensor Circuit Low | Medium |
| P26A7 | Engine Coolant Bypass Valve A Position Sensor Circuit High | Medium |
| P26A8 | Engine Coolant Bypass Valve A Position Sensor Circuit Intermittent/Erratic | Medium |
| P26A9 | Engine Coolant Bypass Valve A Position Sensor Stop/Minimum Stop Performance | Medium |
| P26AA | Engine Coolant Bypass Valve A Position Sensor Maximum Stop Performance | Medium |
| P26AB | Engine Coolant Bypass Valve A Stuck/Open | Medium |
| P26AC | Engine Coolant Bypass Valve B Control Circuit/Open | Medium |
| P26AD | Engine Coolant Bypass Valve B Control Circuit Low | Medium |
| P26AE | Engine Coolant Bypass Valve B Control Circuit High | Medium |
| P26AF | Engine Coolant Bypass Valve B Stuck/Open | Medium |
| P26B0 | Engine Coolant Bypass Valve B Range/Performance | Medium |
| P26B1 | Engine Coolant Bypass Valve A Stuck Closed | Workshop only |
| P26B2 | Engine Coolant Bypass Valve B Stuck Closed | Medium |
| P26B3 | Fuel Shutoff Valve A Control Circuit Performance/Stuck Off | Hard |
| P26B4 | Fuel Shutoff Valve A Control Circuit Stuck On | Hard |
| P26B5 | Fuel Shutoff Valve B Control Circuit Performance/Stuck Off | Hard |
| P26B6 | Fuel Shutoff Valve B Control Circuit Stuck On | Hard |
| P26B7 | Engine Coolant Bypass Valve C Control Circuit/Open | Medium |
| P26B8 | Engine Coolant Bypass Valve C Control Circuit Low | Medium |
| P26B9 | Engine Coolant Bypass Valve C Control Circuit High | Medium |
| P26BA | Engine Coolant Bypass Valve C Stuck/Open | Medium |
| P26BB | Engine Coolant Bypass Valve C Range/Performance | Medium |
| P26BC | Engine Coolant Bypass Valve C Stuck Closed | Medium |
| P26BD | Engine Coolant Bypass Valve D Control Circuit/Open | Medium |
| P26BE | Engine Coolant Bypass Valve D Control Circuit Low | Medium |
| P26BF | Engine Coolant Bypass Valve D Control Circuit High | Medium |
| P26C0 | Engine Coolant Bypass Valve D Stuck/Open | Medium |
| P26C1 | Engine Coolant Bypass Valve D Range/Performance | Medium |
| P26C2 | Engine Coolant Bypass Valve D Stuck Closed | Medium |
| P26C3 | Internal Control Module Transmission Range Sensor Performance | Medium |
| P26C4 | Internal Control Module Clutch Pedal Performance | Medium |
| P26C5 | Exhaust Flow Control Valve A Control Circuit/Open | Medium |
| P26C6 | Exhaust Flow Control Valve A Control Circuit Low | Medium |
| P26C7 | Exhaust Flow Control Valve A Control Circuit High | Medium |
| P26C8 | Chassis Control Module 1 Requested MIL Illumination | Hard |
| P26C9 | Chassis Control Module 2 Requested MIL Illumination | Hard |
| P26CA | Engine Coolant Pump Control Circuit/Open | Medium |
| P26CB | Engine Coolant Pump Performance/Stuck Off | Medium |
| P26CC | Engine Coolant Pump Control Circuit Low | Easy |
| P26CD | Engine Coolant Pump Control Circuit High | Medium |
| P26CE | Engine Coolant Pump Overspeed/Air In System | Medium |
| P26CF | Engine Coolant Pump Control Module System Voltage | Medium |
| P26D0 | Engine Coolant Pump Control Module System Voltage Low | Medium |
| P26D1 | Engine Coolant Pump Control Module System Voltage High | Medium |
| P26D2 | Engine Coolant Pump Control Module Over Temperature | Medium |
| P26D3 | Engine Coolant Pump Supply Voltage Circuit | Medium |
| P26D4 | Engine Coolant Pump Supply Voltage Circuit Low | Medium |
| P26D5 | Engine Coolant Pump Supply Voltage Circuit High | Medium |
| P26D6 | Engine Coolant Pump Clutch Control Circuit/Open | Medium |
| P26D7 | Engine Coolant Pump Clutch Performance/Stuck Off | Hard |
| P26D8 | Engine Coolant Pump Clutch Stuck On | Hard |
| P26D9 | Engine Coolant Pump Clutch Control Circuit Low | Medium |
| P26DA | Engine Coolant Pump Clutch Control Circuit High | Medium |
| P26DB | Engine Sound Control A Circuit/Open | Medium |
| P26DC | Engine Sound Control A Circuit Low | Medium |
| P26DD | Engine Sound Control A Circuit High | Medium |
| P26DE | Engine Sound Control A Circuit Performance | Medium |
| P26DF | Sensor Power Supply D Circuit/Open | Medium |
| P26E0 | Sensor Power Supply D Circuit Low | Medium |
| P26E1 | Sensor Power Supply D Circuit High | Medium |
| P26E2 | Fuel Mode Indicator Lamp Control Circuit Low | Easy |
| P26E3 | Fuel Mode Indicator Lamp Control Circuit High | Easy |
| P26E4 | Starter Relay B Circuit | Medium |
| P26E5 | Starter Relay B Circuit Low | Medium |
| P26E6 | Starter Relay B Circuit High | Medium |
| P26E7 | Actuator Supply Voltage D Circuit/Open | Hard |
| P26E8 | Actuator Supply Voltage D Circuit Low | Hard |
| P26E9 | Actuator Supply Voltage D Circuit High | Hard |
| P26EA | Fuel Pump Control Module B | Medium |
| P26EB | Alternative Fuel Control Module System Voltage | Medium |
| P26EC | Engine Sound Control B Circuit/Open | Medium |
| P26ED | Engine Sound Control B Circuit Low | Medium |
| P26EE | Engine Sound Control B Circuit High | Medium |
| P26EF | Engine Sound Control B Circuit Performance | Medium |
| P26F0 | Starter Relay A Stuck On | Easy |
| P26F1 | Starter Relay A Stuck Off | Easy |
| P26F2 | Starter Relay B Stuck On | Medium |
| P26F3 | Starter Relay B Stuck Off | Easy |
| P26F4 | Coolant Pump C Control Circuit/Open | Medium |
| P26F5 | Coolant Pump C Control Circuit Low | Medium |
| P26F6 | Coolant Pump C Control Circuit High | Medium |
| P26F7 | Coolant Pump C Supply Voltage Circuit | Medium |
| P26F8 | Coolant Pump C Stuck/Stalled | Medium |
| P26F9 | Coolant Pump C Control Module Overtemperature | Medium |
| P26FA | Coolant Pump C Overspeed/Air in System | Easy |
| P26FB | EGR Cooler Bypass Control Stuck Closed (Bank 1) | Medium |
| P26FC | EGR Cooler Bypass Control Stuck Closed (Bank 2) | Medium |
| P26FD | A/C Compressor Internal Control Module Performance | Workshop only |
| P26FE | Exhaust Flow Control Valve A Control Performance | Medium |
| P26FF | Auto Configuration Throttle Input Not Present (Bank 2) | Medium |