| Code | What it means |
| 30 | Sensor heater relay problem |
| 36 | Sensor heater relay problem |
| 106 | MAP sensor voltage out of range detected at startup |
| 107 | MAP sensor voltage too low |
| 108 | MAP sensor voltage too high |
| 112 | Intake air temperature sensor voltage low |
| 113 | Intake air (charge) temperature sensor voltage high |
| 116 | Coolant temparature sensor reading doesn't make sense |
| 117 | Engine coolant temperature sensor voltage low |
| 118 | Engine coolant temperature sensor voltage high |
| 121 | Throttle position sensor and MAP sensor disagree with each other |
| 122 | Throttle position sensor voltage low |
| 123 | Throttle position sensor voltage high |
| 125 | Taking too long to reach proper operating temparature and switch to energy-efficient mode |
| 129 | Bad barometric pressure sensor (thanks, John King) |
| 130 | Sensor heater relay problem |
| 131 | Oxygen sensor seems to be shorted out or broken |
| 147 | Oxygen sensor heater element not working properly (this device helps to reduce emissions more quickly) |
| 151 | Oxygen sensor voltage problem - short circuit to ground? |
| 152 | Oxygen sensor voltage problem - short circuit to active 12V? |
| 153 | Oxygen sensor response too slow |
| 154 | Oxygen sensor does not show either a rich or lean condition - may need replacement |
| 155 | Oxygen sensor heater element not working properly (this device helps to reduce emissions more quickly) |
| 157 | Oxygen sensor voltage problem - short circuit to ground? |
| 158 | Oxygen sensor voltage problem - short circuit to active 12V? |
| 159 | Oxygen sensor response too slow |
| 160 | Oxygen sensor does not show either a rich or lean condition - may need replacement |
| 161 | Oxygen sensor heater element not working properly (this device helps to reduce emissions more quickly) |
| 171 | The oxygen sensor is saying that the system air/fuel mix is far too lean (too much fuel is being added as a correction). |
| 172 | The oxygen sensor is saying that the system air/fuel mix is far too rich (too much air is being added as a correction). |
| 174 | The oxygen sensor is saying that the system air/fuel mix is far too lean (too much fuel is being added as a correction). |
| 175 | The oxygen sensor is saying that the system air/fuel mix is far too rich (too much air is being added as a correction). |
| 176 | Flex fuel sensor can't be seen |
| 178 | Flex fuel sensor problem |
| 179 | Flex fuel sensor problem |
| 182 | Compressed natural gas temperature sensor problem |
| 183 | Compressed natural gas temperature sensor problem |
| 201 | Injector #1 control circuit problem (open or shorted) |
| 202 | Injector #2 control circuit problem (open or shorted) |
| 203 | Injector #3 control circuit problem (open or shorted) |
| 204 | Injector #4 control circuit problem (open or shorted) |
| 300 | Misfire detected in multiple cylinders. |
| 301 | Misfire detected in cylinder #1. |
| 302 | Misfire detected in cylinder #2. |
| 303 | Misfire detected in cylinder #3. |
| 304 | Misfire detected in cylinder #4. |
| 320 | Crankshaft position sensor reference signal cannot be found while the engine is cranking. |
| 325 | Knock sensor (#1) signal is wrong. |
| 330 | Knock sensor (#2) signal is wrong. |
| 340 | No camshaft signal being received by the computer |
| 350 | A coil is drawing too much current. |
| 351 | Coil #1 is not reaching peak current at the right time |
| 352 | Coil #2 is not reaching peak current at the right time |
| 353 | Coil #3 is not reaching peak current at the right time |
| 354 | Coil #4 is not reaching peak current at the right time |
| 401 | A required change in air/fuel mixture was not detected during diagnostic test. |
| 403 | An problem was detected in the EGR solenoid control circuit. |
| 404 | The EGR sensor's reported position makes no sense |
| 405 | EGR position sensor voltage wrong. |
| 406 | EGR position sensor voltage wrong. |
| 412 | The secondary air solenoid control circuit seems bad (this is used for the aspirator). |
| 420 | The catalyst seems inefficient (#1). |
| 432 | The catalyst seems inefficient (#2). |
| 441 | Evaporative purge flow system not working properly |
| 442 | A leak has been detected in the evaporative system! |
| 443 | Evaporative purge flow system solenoid not working properly |
| 455 | A large leak has been detected in the evaporative system! |
| 456 | A small leak has been detected in the evaporative system! |
| 460 | The fuel level sender is not reporting any change over a long distance. Something seems wrong. |
| 461 | The fuel level sender is not reporting any change over a long time. Something seems wrong. |
| 462 | Fuel level sender voltage wrong. |
| 463 | Fuel level sender voltage wrong. |
| 500 | Haven't heard from the speed sensor lately. |
| 505 | The idle speed air control motor doesn't seem to be working correctly. |
| 522 | Oil pressure sensor problems |
| 523 | Oil pressure sensor problems |
| 551 | The power steering switch may not be working. (Neons: high pressure is showing up at high speed) |
| 600 | Oh-oh! The coprocessors aren't talking to each other within the computer! |
| 601 | Internal computer error! |
| 604 | Internal computer error! (RAM check) |
| 605 | Internal computer error! (ROM) |
| 615 | Starter relay circuit problem |
| 622 | Generator field control problem |
| 645 | A/C clutch relay circuit problem. |
| 700 | The automatic transmission computer has a problem - ask it what's going on. I don't know. All I know is that the transmission asked me to turn on the MIL (malfunction indicator light). I did it, didn't I? So why are you bugging ME? ... you may have error code 1776, too. I'd check for that. It's patriotic and more informative. |
| 703 | Brake switch circuit information seems wrong. |
| 711 | Based on the transmission temperature and its operations, it looks like the transmission temperature sensor's gone bad. |
| 712 | Transmission fluid temperature sensor voltage wrong. |
| 713 | Transmission fluid temperature sensor voltage wrong. |
| 720 | The Output Shaft Speed Sensor doesn't match the reported vehicle speed. |
| 740 | The engine's running faster than it should for these speeds, so I think thetorque convertor clutch lock-up system is bad |
| 743 | Torque converter clutch (part throttle unlock) solenoid circuit problem - shift solenoid C electrical fault |
| 748 | Governor Pressure Solenoid circuit problem (Transmission relay circuit problem in Jeep RE transmissions) |
| 751 | Overdrive override switch has been pressed for over five minutes. Just thought you should know. |
| 753 | Overdrive solenoid control circuit problem (transmission relay circuit in Jeep RE transmissions.) |
| 756 | Shift solenoid B (2-3) fault |
| 783 | The overdrive solenoid can't go from 3rd gear to the overdrive gear. |
| 801 | Transmission reverse gear lockout solenoid circuit problem! |
| 833 | Problem with the clutch-released switch circuit? |