2005 Jeep OBD2 Codes: A Comprehensive Guide to Troubleshooting Your Check Engine Light

Navigating car troubles can be stressful, especially when that ominous check engine light illuminates on your 2005 Jeep. Fortunately, modern vehicles like your 2005 Jeep Wrangler, Grand Cherokee, or Liberty are equipped with an On-Board Diagnostics system, specifically OBD2, which can provide valuable clues about what’s going wrong. Understanding 2005 Jeep Obd2 Codes is the first step in diagnosing issues and getting your Jeep back on the road with confidence.

This guide will delve into the world of 2005 Jeep OBD2 codes, helping you understand how to retrieve these codes and what they might signify. We’ll explore common codes, diagnostic procedures, and what steps you can take to address potential problems. While this guide aims to be comprehensive, it’s crucial to remember that it serves as a troubleshooting aid and not a definitive repair manual. Always consult with a certified mechanic for accurate diagnosis and repairs.

Decoding OBD2 Codes on Your 2005 Jeep

Before diving into the specifics of 2005 Jeep OBD2 codes, let’s understand how to access this diagnostic information. The process, often referred to as the “key trick,” allows you to retrieve basic OBD codes without specialized tools on many Jeep models. It’s important to note that while this method can be helpful, a dedicated OBD2 code reader provides more detailed and accurate information.

Here are two methods to try retrieving codes from your 2005 Jeep. Note that results can vary depending on the specific model and its electronic systems.

Method 1: The “Key Trick” for Newer (OBDII) Models

This method is generally applicable to 2005 Jeep models which are OBD2 compliant.

1. Insert your key into the ignition.
2. Press and hold the odometer reset button. Keep holding it down throughout the next steps.
3. Turn the ignition key to the “RUN” position. This is the position just before starting the engine. Do not start the engine.
4. Release the odometer reset button.
5. Observe the Odometer Display: The odometer will go through a series of displays, often starting with “111111” and progressing through “999999”. It may then display the vehicle’s serial number. After this sequence, it should begin to display any stored error codes. These codes may start with a “P” (for Powertrain codes).

If this method doesn’t yield codes, you can attempt the OBDI method, although it’s less likely to work on a 2005 Jeep, which is designed for OBD2.

Method 2: The “Key Trick” for Older (OBDI) Method (Less Likely for 2005 Models but Worth a Try)

This method is designed for older OBDI systems, but might still be worth attempting if the OBDII method fails, or for comparative purposes.

1. Ensure the ignition is switched OFF.
2. Within five seconds, cycle the ignition key between “ON” and “OFF” three times, ending in the “ON” position. The sequence is: ON – OFF – ON – OFF – ON. Remember “ON” is the RUN position, not START, and “OFF” is not LOCK.
3. Observe the “Check Engine” Light: The “check engine” light will begin to flash. Count the flashes to decipher the codes. Two-digit codes are indicated by flashes, for example, code 23 would be FLASH FLASH (pause) FLASH FLASH FLASH (long pause). A code 55 indicates the end of the code sequence and is normal.

Important Notes on Retrieving Codes:

• Parking Brake: In some instances, setting the parking brake might be necessary for the codes to display correctly.
• Code Repetition: Codes are generally not repeated. If you see a sequence like 23 23, it’s likely a single code 23 followed by the end-of-codes signal (55).
• Digital Odometer Display: Newer models often display codes directly on the digital odometer, rather than flashing the check engine light.
• Limp Mode: In severe cases, the vehicle’s computer might activate “Limp In” mode to protect the engine. This mode can cause symptoms like loss of third and fourth gear in automatic transmissions.

While these “key trick” methods can provide basic codes, they are limited. For a more thorough and accurate diagnosis of your 2005 Jeep OBD2 codes, using a dedicated OBD2 scanner is highly recommended. These scanners are readily available and can provide more specific code definitions and even clear codes after repairs are made.

Understanding 2005 Jeep OBD2 Codes: Code Lists

Once you’ve retrieved the codes from your 2005 Jeep, the next step is to understand what they mean. OBD2 codes are standardized across the automotive industry, but knowing the specific code list relevant to Chrysler vehicles, including Jeeps, is crucial.

Below are comprehensive lists of OBD codes, categorized as “Older Model Computer Codes (OBDI)” and “Newer model Computer codes (OBDII)” as provided in the original source. While your 2005 Jeep primarily uses OBD2, the OBDI list is included for reference and in case older systems are relevant to specific components or for comparative understanding.

Older Model Computer Codes (OBDI) – (Potentially Relevant for Older Systems or Reference)

IMPORTANT! These codes may be different for vehicles starting circa 1996 and are less likely to be the primary codes for a 2005 Jeep, which is designed to be OBD2 compliant.

• 11 No ignition reference signal detected during cranking OR timing belt skipped one or more teeth; OR loss of either camshaft or crankshaft position sensor.
• 12 Battery or computer recently disconnected
• 13 MAP sensor or vacuum line may not be working
• 14 MAP sensor voltage below .16V or over 4.96V
• 15 No speed/distance sensor signal
• 16 Loss of battery voltage detected with engine running
• 17 Engine stays cool too long (bad thermostat or coolant sensor?) OR 17 (1985 turbo only): knock sensor circuit
• 21 Oxygen sensor signal doesn’t change (stays at 4.3-4.5V). Probably bad oxygen sensor
• 22 Coolant sensor signal out of range – May have been disconnected to set timing
• 23 Incoming air temperature sensor may be bad
• 24 Throttle position sensor over 4.96V
• 25 Automatic Idle Speed (AIS) motor driver circuit shorted or target idle not reached
• 26 Peak injector circuit voltage has not been reached (need to check computer signals, voltage reg, injectors)
• 27 Injector circuit isn’t switching when it’s told to (TBI) OR (MPI) injector circuit #1 not switching right OR (turbo) injector circuit #2 not switching right OR (all 1990-) injector output driver not responding – check computer, connections
• 31 Bad evaporator purge solenoid circuit or driver
• 32 (1984 only) power loss/limited lamp or circuit OR 32 EGR gases not working (1988) – check vacuum, valve OR 32 (1990-92) computer didn’t see change in air/’fuel ratio when EGR activated – check valve, vacuum lines, and EGR electrical
• 33 Air conditioning clutch relay circuit open or shorted (may be in the wide-open-throttle cutoff circuit or normal on early 80’s models if you don’t have air conditioning)
• 34 (1984-86) EGR solenoid circuit shorted or open OR 34 (1987-1991) speed control shorted or open
• 35 Cooling fan relay circuit open or shorted OR 35 idle switch motor fault – check connections
• 36 (turbo only) Wastegate control circuit open or shorted
• 37 Shift indicator light failure, 5-speed OR part throttle lock/unlock solenoid driver circuit (87-89) OR solenoid coil circuit (85-87 Turbo only) OR Trans temperature sensor voltage low (1995 and on)
• 41 Alternator field control circuit open or shorted
• 42 Automatic shutdown relay circuit open or shorted OR 42 Fuel pump relay control circuit OR 42 Fuel level unit – no change over miles OR 42 Z1 voltage missing when autoshutdown circuit energized (The Z1 voltage is the voltage of the circuits fed by the autoshutdown relay. This typically includes fuel pump and switched-battery feed to the ignition coil)
• 43 Peak primary coil current not achieved with max dwell time OR 43 Cylinder misfire OR 43 Problem in power module to logic module interface
• 44 No FJ2 voltage present at logic board OR 44 Logic module self-diagnostics indicate problem OR 44 Battery temperature out of range
• 45 Turbo boost limit exceeded (engine was shut down by logic module)
• 46 Battery voltage too high during charging or charging system voltage too low
• 47 Battery voltage too low and alternator output too low
• 51 Oxygen sensor stuck at lean position (this may be tripped by a bad MAP sensor system causing a rich condition. If you get hot rough idle and stalling, especially on deceleration, accompanied by flooded engine and difficulty restarting, that can be a bad MAP sensor causing the O2 sensor to try to compensate. If you get poor cold driveability, stumbling and bucking, and acceptable warm driving with poor gas mileage (a drop of 10 mpg or more), that is usually the O2 sensor. OR 51 Internal logic module fault (’84 turbo only).
• 52 Oxygen sensor stuck at rich position OR 52 Internal logic module fault (’84 turbo only)
• 53 Logic module internal problem
• 54 No sync pickup signal during engine rotation (turbo only) OR 54 Internal logic module fault (’84 turbo only) – or camshaft sensor/distributor timing
• 55 End of codes
• 61 “Baro” sensor open or shorted
• 62 EMR mileage cannot be stored in EEPROM or PCM failure SRI mile not stored
• 63 Controller cannot write to EEPROM
• 64 Catalytic converter efficiency failure
• 65 Power steering switch failure
• 66 No CCD Message From TCM and/or No CCD Message From BCM

Newer model Computer codes (OBDII) – Primarily Relevant for 2005 Jeep Models

These codes are the most relevant for diagnosing issues in your 2005 Jeep. OBD2 codes are generally five characters long. While this list provides numeric codes, a proper OBD2 scanner will usually display the full code format (e.g., P0106 instead of 106).

• 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
• 130 Sensor heater relay problem or O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
• 131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
• 132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)
• 133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
• 134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
• 135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
• 136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
• 137 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
• 138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
• 139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
• 140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
• 141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
• 142 O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)
• 143 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)
• 144 O2 Sensor Circuit High Voltage (Bank 1 Sensor 3)
• 145 O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)
• 146 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3)
• 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)
• 205 Injector #5 control circuit problem (open or shorted)
• 206 Injector #6 control circuit problem (open or shorted)
• 207 Injector #7 control circuit problem (open or shorted)
• 208 Injector #8 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.
• 305 Misfire detected in cylinder #5.
• 306 Misfire detected in cylinder #6.
• 307 Misfire detected in cylinder #7
• 308 Misfire detected in cylinder #8.
• 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
• 355 Coil #5 is not reaching peak current at the right time
• 356 Coil #6 is not reaching peak current at the right time
• 357 Coil #7 is not reaching peak current at the right time
• 358 Coil #8 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 or Aisin computer has a problem – ask it what’s going on. I don’t know.
• 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?
• 1192 Inlet air temperature sensor voltage is wrong
• 1193 Inlet air temperature sensor voltage is wrong
• 1194 Oxygen sensor heater performance is faulty
• 1195 Oxygen sensor is slow
• 1196 The oxygen sensor switched too slowly (bank 2).
• 1197 The oxygen sensor switched too slowly (bank 1).
• 1198 Radiator coolant temperature sensor voltage is wrong.
• 1199 Radiator coolant temperature sensor voltage is wrong.
• 1281 The engine is staying cold too long – check your thermostat.
• 1282 The fuel pump relay circuit seems to be having a problem.
• 1288 The intake manifold short runner tuning valve circuit seems to be having a problem.
• 1289 There’s a problem in the manifold tuning valve solenoid control circuit.
• 1290 Compressed natural gas system pressure is too high
• 1291 The heated air intake sensor does not seem to be working.
• 1292 Natural gas pressure sensor issue
• 1293 Natural gas pressure sensor issue
• 1294 Can’t get to target engine speed, check for vacuum leaks and idle speed motor issues.
• 1295 The throttle position sensor doesn’t seem to be getting enough electricity.
• 1296 The MAP sensor doesn’t seem to be getting enough electricity.
• 1297 The MAP sensor doesn’t change its reading when the engine is running!
• 1298 During wide-open throttle, the engine runs lean.
• 1299 MAP Sensor and Throttle Position Sensor signals don’t match, check for a vacuum leak.
• 1388 Auto shutdown relay circuit problems?
• 1389 No Z1 or Z2 voltage seen by the computer when the auto shutdown relay is used.
• 1390 Cam and crank signals don’t match – did the timing belt skip a tooth?
• 1391 Sometimes, I can’t see the crank or cam sensor signal.
• 1398 I can see the Crank Sensor’s signal when I prepare for Misfire Diagnostics. Try replacing it.
• 1399 Problem in the Wait to Start Lamp circuit – (diesels only?)
• 1403 EGR position sensor not getting (enough) voltage.
• 1476 Too little secondary air injection during aspirator test.
• 1477 Too much secondary air injection during aspirator test.
• 1478 Battery temperature sensor voltage wrong.
• 1479 Transmission fan relay circuit problems?
• 1480 PCV solenoid circuit problems?
• 1481 Transmission RPM pulse generator signal for misfire detection seems wrong.
• 1482 Catalyst temperature sensor circuit shorted low.
• 1483 Catalyst temperature sensor circuit shorted high.
• 1484 The catalyst seems to be overheating!
• 1485 Air injection solenoid circuit problems.
• 1486 Pinched or blocked hose in the evaporative hose system.
• 1487 Control circuit of the #2 high-speed radiator fan control relay is having problems.
• 1488 Auxiliary 5-volt sensor feed is too low.
• 1489 High speed radiator fan control circuit problem.
• 1490 Low speed radiator fan control circuit problem.
• 1491 Radiator fan control circuit problem (may be solid state relays as well as other circuits).
• 1492 Ambient or battery temperature sensor voltage wrong
• 1493 Ambient or battery temperature sensor voltage wrong
• 1494 Leak Detection Pump (LDP) pressure switch problem – electrical or the pump itself.
• 1495 Leak Detection Pump (LDP) pressure switch problem – the solenoid circuit.
• 1496 Sensor feed is below an acceptable limit. (under 4v for 4 seconds – should be 5v).
• 1498 High speed radiator fan control circuit problem. (#3 control relay)
• 1594 Voltage too high in charging system.
• 1595 Speed control vacuum or vent solenoid control circuits shorted or lost.
• 1596 Speed control switch always high
• 1597 Speed control switch always low
• 1598 A/C pressure sensor voltage high
• 1599 A/C pressure sensor voltage low
• 1681 No messages received from the cluster control module (dashboard computer).
• 1682 Charging system doesn’t seem to be working well. Check alternator, etc.
• 1683 Speed control servo power control circuit problem.
• 1684 The battery has been disconnected within the last 50 starts.
• 1685 Invalid key received from the Smart Key Immobilizer Module.
• 1686 No messages received from the Smart Key Immobilizer Module.
• 1687 No messages received from the Mechanical Instrument Cluster module.
• 1693 The companion engine control module has shown a fault.
• 1694 No messages received from the powertrain control module-Aisin transmission.
• 1695 No messages received from the body control module.
• 1696 Unsuccessful attempt to write to an EEPROM location!
• 1697 Unsuccessful attempt to update Service Reminder Indicator (SRI or EMR) mileage!
• 1698 No messages received from the electronic transmission control module or the Aisin transmission controller.
• 1719 Transmission 2-3 gear lockout solenoid control circuit problem.
• 1740 Either the tcc solenoid or overdrive solenoid systems doesn’t seem to be making much sense.
• 1756 Transmission control pressure not equal to target. (Mid pressure problem)
• 1757 Transmission control pressure not equal to target. (Zero pressure problem)
• 1762 The Governor Pressure Sensor input was too high or too low for 3 consecutive park/neutral calibrations.
• 1763 The Governor Pressure Sensor input is too high
• 1764 The Governor Pressure Sensor input is too low.
• 1765 Open or short in the Transmission Relay control circuit.
• 1899 The Park/Neutral switch seems to be stuck!

Important Disclaimer:

This OBD code list is intended as a guide for troubleshooting your 2005 Jeep OBD2 codes. It is compiled from various sources and may not be exhaustive or perfectly accurate. OBD codes provide a starting point for diagnosis, but they do not pinpoint the exact cause of a problem in every situation.

Modern vehicle computer systems can be complex. Codes may not always reflect the actual failed component, but rather indicate a symptom or reading outside of expected parameters. A code might point to a sensor, but the actual issue could be with wiring, connections, or even a different component affecting the sensor’s readings.

Therefore, this guide should ONLY be used as an aid in troubleshooting and NOT as a repair manual. For accurate diagnosis and reliable repairs, always consult a qualified and certified automotive technician. They have the expertise, specialized tools, and diagnostic equipment to properly interpret OBD2 codes and perform the necessary repairs on your 2005 Jeep.

End Disclaimer

By understanding how to retrieve and interpret 2005 Jeep OBD2 codes, you can be more informed about your vehicle’s health and communicate effectively with your mechanic. This knowledge empowers you to take proactive steps in maintaining your 2005 Jeep and ensuring its reliable performance for years to come.