Technical Presentation KitTechnical Presentation KitEnginesEnginesExitExitMenuMenuSAA6D140/125-CRISAA6D140/125-CRIKT900201KT900201February 2001February 2001SAA6D140/125-CRI故障代码故障代码Section 5KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2 2ExitExitMenuMenu处理控制器的高压回路处理控制器的高压回路处理控制器的高压回路处理控制器的高压回路控制器对喷射嘴的控制电压是 (110 130V) 因此从控制器到喷射嘴的回路都是高压的回路.回路中只有在发动机运转中才是高压的，当发动机停止时不带高压。直接接触高压回路非常危险，因此检查前要注意下面的警示标志。KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3 3ExitExitMenuMenu处理控制器的高压回路处理控制器的高压回路处理控制器的高压回路处理控制器的高压回路1. 有关高压回路的相关接头有关高压回路的相关接头 控制器接头: CN6, CN7 中间接头: EC1 喷射嘴接头: IJ1, IJ2, IJ3, IJ4, IJ5, IJ6 喷射嘴上的连接线（缸盖里面)2. 每次断开或接上接头时，都要把起动开关置于每次断开或接上接头时，都要把起动开关置于 OFF3. 如果连有如果连有 T 分岐分岐接头进行故障分晰时，千万不能打开发接头进行故障分晰时，千万不能打开发动机动机*如果动开关，只能 ON 或 OFF ，千万不能起动发动机KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4 4ExitExitMenuMenu故障代码故障代码KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5 5ExitExitMenuMenuECM -错误码- 非当前码KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-6 6ExitExitMenuMenuECM -错误代码 当前码KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-7 7ExitExitMenuMenu故障代码故障代码故障代码显示故障代码显示 发动机控制器用两位数显示发动机出现的故障. 当起动开关ON 时，显示 88, 然后显示 E 和两位数字码重复显示故障.如果有多个故障，则按顺序一遍一遍重复显示 为防止读错，数字与字母显示如下数字: 0 1 2 3 4 5 6 7 8 9字母: A b C d E 当要重新演示故障或故障修复后，在起动开关ON 时，把接头CN4 的第4脚接地。KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-8 8ExitExitMenuMenu故障代码表故障代码表Click on Code for Troubleshooting StepsClick on Code for Troubleshooting StepsPage two of Codes for TroubleshootingPage two of Codes for TroubleshootingKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-9 9ExitExitMenuMenu故障代码表故障代码表Click on Code for Troubleshooting StepsClick on Code for Troubleshooting StepsPage one of Codes for TroubleshootingPage one of Codes for TroubleshootingKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1010ExitExitMenuMenuE-1 Error code E-1b Abnormality in NE revolution sensor systemError code E-1b Abnormality in NE revolution sensor system Return To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1111ExitExitMenuMenuE-2E-2 Error code E-1C Abnormality in G revolution sensor systemError code E-1C Abnormality in G revolution sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1212ExitExitMenuMenuE-3E-3 Error code E-20 Abnormality in model selection system Error code E-20 Abnormality in model selection systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1313ExitExitMenuMenuE-4E-4 Error code E-22 OverrunError code E-22 OverrunReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1414ExitExitMenuMenuE-5 Error code E-23 OverheatError code E-23 OverheatReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1515ExitExitMenuMenuE-6E-6 Error code E-24 Drop in oil pressureError code E-24 Drop in oil pressureReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1616ExitExitMenuMenuE-7E-7 Error code E-30 Abnormality in idling validation signal systemError code E-30 Abnormality in idling validation signal systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1717ExitExitMenuMenuE-7E-7 Error code E-30 Abnormality in idling validation signal systemError code E-30 Abnormality in idling validation signal systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1818ExitExitMenuMenuE-8E-8 Error code E-31 Abnormality in throttle sensor systemError code E-31 Abnormality in throttle sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-1919ExitExitMenuMenuE-8E-8 Error code E-31 Abnormality in throttle sensor systemError code E-31 Abnormality in throttle sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2020ExitExitMenuMenuE-8E-8 Error code E-31 Abnormality in throttle sensor systemError code E-31 Abnormality in throttle sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2121ExitExitMenuMenuE-9E-9 Error code E-34 Abnormality in water temperature high-Error code E-34 Abnormality in water temperature high-temperature sensor systemtemperature sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2222ExitExitMenuMenuE-9E-9 Error code E-34 Abnormality in water temperature high-Error code E-34 Abnormality in water temperature high-temperature sensor systemtemperature sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2323ExitExitMenuMenuE-10E-10 Error code E-36 Abnormality in oil pressure switch systemError code E-36 Abnormality in oil pressure switch systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2424ExitExitMenuMenuE-10E-10 Error code E-36 Abnormality in oil pressure switch systemError code E-36 Abnormality in oil pressure switch systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2525ExitExitMenuMenuE-11E-11 Error code E-3C Abnormality in boost pressure sensor systemError code E-3C Abnormality in boost pressure sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2626ExitExitMenuMenuE-11E-11 Error code E-3C Abnormality in boost pressure sensor systemError code E-3C Abnormality in boost pressure sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2727ExitExitMenuMenuE-12E-12 Error code E-3d Abnormality in fuel temperature sensor systemError code E-3d Abnormality in fuel temperature sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2828ExitExitMenuMenuE-12E-12 Error code E-3d Abnormality in fuel temperature sensor systemError code E-3d Abnormality in fuel temperature sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-2929ExitExitMenuMenuE-13E-13 Error code E-50 Abnormality in preheating relay connecting Error code E-50 Abnormality in preheating relay connecting point systempoint systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3030ExitExitMenuMenuE-14E-14 Error code E-51 Abnormality in preheat relay coil systemError code E-51 Abnormality in preheat relay coil systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3131ExitExitMenuMenuE-15E-15 Error code E-54 Short circuit in starting switch C systemError code E-54 Short circuit in starting switch C systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3232ExitExitMenuMenuE-16E-16 Error code E-56 Power source system abnormality 1Error code E-56 Power source system abnormality 1Return To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3333ExitExitMenuMenuE-16E-16 Error code E-56 Power source system abnormality 1Error code E-56 Power source system abnormality 1Return To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3434ExitExitMenuMenuE-17E-17 Error code E-57 Power source system abnormality 2Error code E-57 Power source system abnormality 2Return To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3535ExitExitMenuMenuE-18E-18 Error code E-5A Abnormality in fuel injection quantity control switch signalError code E-5A Abnormality in fuel injection quantity control switch signalReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3636ExitExitMenuMenuE-19E-19 Error code E-6A Abnormality in water temperature low-Error code E-6A Abnormality in water temperature low-temperature sensor systemtemperature sensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3737ExitExitMenuMenuReturn To Table Return To Table of Error Codesof Error CodesE-19E-19 Error code E-6A Abnormality in water temperature low-Error code E-6A Abnormality in water temperature low-temperature sensor systemtemperature sensor systemKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3838ExitExitMenuMenuE-20E-20 Error code E-70 Excess current in fuel supply pump PCV1 systemError code E-70 Excess current in fuel supply pump PCV1 systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-3939ExitExitMenuMenuE-21E-21 Error code E-71 Excess current in fuel supply pump PCV2 systemError code E-71 Excess current in fuel supply pump PCV2 systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4040ExitExitMenuMenuE-22E-22 Error code E-74 Disconnection in fuel supply pump PCV1 systemError code E-74 Disconnection in fuel supply pump PCV1 systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4141ExitExitMenuMenuE-23E-23 Error code E-75 Disconnection in fuel supply pump PCV2 systemError code E-75 Disconnection in fuel supply pump PCV2 systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4242ExitExitMenuMenuE-24E-24 Error code E-77 Abnormality in common rail fuel pressure Error code E-77 Abnormality in common rail fuel pressure sensor systemsensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4343ExitExitMenuMenuE-24E-24 Error code E-77 Abnormality in common rail fuel pressure Error code E-77 Abnormality in common rail fuel pressure sensor systemsensor systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4444ExitExitMenuMenuE-25E-25 Error code E-79 Common rail fuel high pressure abnormality 1Error code E-79 Common rail fuel high pressure abnormality 1Error code E-7A Common rail fuel high pressure abnormality 2Error code E-7A Common rail fuel high pressure abnormality 2Return To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4545ExitExitMenuMenuE-26E-26 Error code E-7b Fuel supply pump non-force feed 1Error code E-7b Fuel supply pump non-force feed 1Error code E-7C Fuel supply pump non-force feed 2Error code E-7C Fuel supply pump non-force feed 2Return To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4646ExitExitMenuMenuReturn To Table Return To Table of Error Codesof Error CodesE-26E-26 Error code E-7b Fuel supply pump non-force feed 1Error code E-7b Fuel supply pump non-force feed 1Error code E-7C Fuel supply pump non-force feed 2Error code E-7C Fuel supply pump non-force feed 2KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4747ExitExitMenuMenuE-27E-27 Error code E-7d Abnormality in common rail fuel pressureError code E-7d Abnormality in common rail fuel pressureReturn To Table Return To Table of Error Codesof Error CodesGo to Troubleshooting of error codes E-79 and E-7A.KT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4848ExitExitMenuMenuE-28E-28 Error code E-80 Defective controllerError code E-80 Defective controllerReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-4949ExitExitMenuMenuE-29E-29 Error code E-81 Disconnection in No. 1 fuel injector systemError code E-81 Disconnection in No. 1 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5050ExitExitMenuMenuE-30E-30 Error code E-82 Disconnection in No. 2 fuel injector systemError code E-82 Disconnection in No. 2 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5151ExitExitMenuMenuE-31E-31 Error code E-83 Disconnection in No. 3 fuel injector systemError code E-83 Disconnection in No. 3 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5252ExitExitMenuMenuE-32E-32 Error code E-84 Disconnection in No. 4 fuel injector system Error code E-84 Disconnection in No. 4 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5353ExitExitMenuMenuE-33E-33 Error code E-85 Disconnection in No. 5 fuel injector systemError code E-85 Disconnection in No. 5 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5454ExitExitMenuMenuE-34E-34 Error code E-86 Disconnection in No. 6 fuel injector systemError code E-86 Disconnection in No. 6 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5555ExitExitMenuMenuE-35E-35 Error code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemError code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5656ExitExitMenuMenuE-35E-35 Error code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemError code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5757ExitExitMenuMenuE-35E-35 Error code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemError code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5858ExitExitMenuMenuE-35E-35 Error code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemError code E-8A Short circuit in No. 1, No. 2, No. 3 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-5959ExitExitMenuMenuE-36E-36 Error code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemError code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-6060ExitExitMenuMenuE-36E-36 Error code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemError code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-6161ExitExitMenuMenuE-36E-36 Error code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemError code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemReturn To Table Return To Table of Error Codesof Error CodesKT900201 - TroubleshootingKT900201 - TroubleshootingSAA6D140/125-CRISAA6D140/125-CRITPKTPK02/0002/00Page 5-Page 5-6262ExitExitMenuMenuE-36E-36 Error code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemError code E-8b Short circuit in No. 3, No. 4, No. 5 fuel injector systemReturn To Table Return To Table of Error Codesof Error Codes