Decoding 1996 Jeep Grand Cherokee OBD2 Codes: Your Comprehensive Guide

Navigating car troubles can be daunting, especially when the check engine light illuminates in your 1996 Jeep Grand Cherokee. Fortunately, the implementation of On-Board Diagnostics II (OBD2) systems in vehicles like yours simplifies the diagnostic process. This guide serves as your expert resource to understand and utilize OBD2 codes specifically for your 1996 Jeep Grand Cherokee. We’ll delve into how to retrieve these codes and what they mean, empowering you to take informed steps towards vehicle maintenance and repair.

Retrieving OBD2 Codes on Your 1996 Jeep Grand Cherokee

Before diving into the error codes themselves, it’s crucial to know how to access them from your Jeep’s computer system. For 1996 Jeep Grand Cherokee models, there are a couple of methods you can employ to retrieve these diagnostic trouble codes (DTCs).

The “Key Trick” Method for OBDII Jeeps

This method is a built-in feature of your Jeep and doesn’t require any special tools. Here’s how to perform the key trick to display OBD2 codes on your 1996 Grand Cherokee:

Start with the ignition off. Ensure your key is not in the ignition.
Push and hold the odometer reset button. Locate the odometer reset button on your instrument cluster and press it down, keeping it pressed throughout the next steps.
Turn the key to the RUN position. While holding the odometer reset button, insert your key into the ignition and turn it to the “RUN” position. This is the position just before you would start the engine.
Release the odometer reset button. Once the key is in the “RUN” position, release the odometer reset button.

After releasing the button, observe the odometer display. It will typically go through a sequence of numbers (111111 to 999999), then display the vehicle’s serial number. Following this, the odometer will display any stored Diagnostic Trouble Codes (DTCs). These codes might begin with a “P” (for Powertrain codes). Write down any codes displayed. The code “55” indicates the “end of codes” and is a normal message, not an error.

Alt text: Jeep Grand Cherokee instrument cluster highlighting the odometer, used for displaying OBD2 error codes via the key trick method.

Using an OBD2 Scanner

For a more user-friendly and sometimes more detailed approach, you can use a dedicated OBD2 scanner. These scanners are readily available online and at auto parts stores at varying price points.

Locate the OBD2 port. In a 1996 Jeep Grand Cherokee, the OBD2 port is typically located under the dashboard on the driver’s side. It’s usually near the steering column or slightly to the left.
Plug in the OBD2 scanner. With the ignition off, plug your OBD2 scanner into the port.
Turn the ignition to the RUN position. Turn the key to the “RUN” position (but do not start the engine).
Follow the scanner’s instructions. Most scanners will power on automatically once plugged in. Follow the on-screen prompts to read diagnostic codes. Typically, you’ll need to select an option like “Read Codes” or “Diagnostic Codes.”

The scanner will then display any stored DTCs along with often providing a brief description of the code. Some advanced scanners can also offer live data readings from the vehicle’s sensors, which can be helpful for more in-depth diagnostics.

Understanding OBD2 Codes for Your 1996 Jeep Grand Cherokee

Once you have retrieved the OBD2 codes, the next step is to understand what they mean. OBD2 codes are standardized across most vehicle manufacturers, but knowing the specific context for your 1996 Jeep Grand Cherokee is crucial.

Important Disclaimer: It’s important to note that the following list is a comprehensive guide compiled from various sources but may not be entirely exhaustive or perfectly accurate for every situation. Diagnostic codes are intended to aid in troubleshooting and should not be used as a definitive repair manual. Always consult a qualified mechanic for accurate diagnosis and repair advice. Keep in mind that a fault code indicates a potential issue within a system, but the actual root cause may require further investigation. A code points you in the direction, but further diagnosis is often needed.

General OBD2 Code List for 1996 Jeep Grand Cherokee

Here is a list of OBD2 codes that may be relevant to your 1996 Jeep Grand Cherokee. Note that some codes might be more generic Chrysler/Jeep codes rather than exclusively for the Grand Cherokee.

P00xx – Fuel and Air Metering

P0106: MAP sensor voltage out of range detected at startup
P0107: MAP sensor voltage too low
P0108: MAP sensor voltage too high
P0112: Intake air temperature sensor voltage low
P0113: Intake air (charge) temperature sensor voltage high
P0116: Coolant temperature sensor reading doesn’t make sense
P0117: Engine coolant temperature sensor voltage low
P0118: Engine coolant temperature sensor voltage high
P0121: Throttle position sensor and MAP sensor disagree with each other
P0122: Throttle position sensor voltage low
P0123: Throttle position sensor voltage high
P0125: Taking too long to reach proper operating temperature and switch to energy-efficient mode
P0130: O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P0131: O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
P0132: O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)
P0133: O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0134: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
P0135: O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0136: O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0137: O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
P0138: O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0139: O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0140: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
P0141: O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0142: O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)
P0143: O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)
P0144: O2 Sensor Circuit High Voltage (Bank 1 Sensor 3)
P0145: O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)
P0146: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3)
P0147: Oxygen sensor heater element not working properly (Bank 1 Sensor 1)
P0151: Oxygen sensor voltage problem – short circuit to ground? (Bank 1 Sensor 2)
P0152: Oxygen sensor voltage problem – short circuit to active 12V? (Bank 1 Sensor 2)
P0153: Oxygen sensor response too slow (Bank 1 Sensor 2)
P0154: Oxygen sensor does not show either a rich or lean condition – may need replacement (Bank 1 Sensor 2)
P0155: Oxygen sensor heater element not working properly (Bank 1 Sensor 2)
P0157: Oxygen sensor voltage problem – short circuit to ground? (Bank 2 Sensor 1)
P0158: Oxygen sensor voltage problem – short circuit to active 12V? (Bank 2 Sensor 1)
P0159: Oxygen sensor response too slow (Bank 2 Sensor 1)
P0160: Oxygen sensor does not show either a rich or lean condition – may need replacement (Bank 2 Sensor 1)
P0161: Oxygen sensor heater element not working properly (Bank 2 Sensor 1)
P0171: System too Lean (Bank 1)
P0172: System too Rich (Bank 1)
P0174: System too Lean (Bank 2)
P0175: System too Rich (Bank 2)
P0176: Flex fuel sensor can’t be seen
P0178: Flex fuel sensor problem
P0179: Flex fuel sensor problem
P0182: Compressed natural gas temperature sensor problem
P0183: Compressed natural gas temperature sensor problem

P02xx – Injector Circuit

P0201: Injector #1 control circuit problem (open or shorted)
P0202: Injector #2 control circuit problem (open or shorted)
P0203: Injector #3 control circuit problem (open or shorted)
P0204: Injector #4 control circuit problem (open or shorted)
P0205: Injector #5 control circuit problem (open or shorted)
P0206: Injector #6 control circuit problem (open or shorted)
P0207: Injector #7 control circuit problem (open or shorted)
P0208: Injector #8 control circuit problem (open or shorted)

P03xx – Ignition System or Misfire

P0300: Misfire detected in multiple cylinders.
P0301: Misfire detected in cylinder #1.
P0302: Misfire detected in cylinder #2.
P0303: Misfire detected in cylinder #3.
P0304: Misfire detected in cylinder #4.
P0305: Misfire detected in cylinder #5.
P0306: Misfire detected in cylinder #6.
P0307: Misfire detected in cylinder #7
P0308: Misfire detected in cylinder #8.
P0320: Crankshaft position sensor reference signal cannot be found while the engine is cranking.
P0325: Knock sensor (#1) signal is wrong.
P0330: Knock sensor (#2) signal is wrong.
P0340: No camshaft signal being received by the computer
P0350: A coil is drawing too much current.
P0351: Coil #1 is not reaching peak current at the right time
P0352: Coil #2 is not reaching peak current at the right time
P0353: Coil #3 is not reaching peak current at the right time
P0354: Coil #4 is not reaching peak current at the right time
P0355: Coil #5 is not reaching peak current at the right time
P0356: Coil #6 is not reaching peak current at the right time
P0357: Coil #7 is not reaching peak current at the right time
P0358: Coil #8 is not reaching peak current at the right time

P04xx – Auxiliary Emission Controls

P0401: A required change in air/fuel mixture was not detected during diagnostic test.
P0403: An problem was detected in the EGR solenoid control circuit.
P0404: The EGR sensor’s reported position makes no sense
P0405: EGR position sensor voltage wrong.
P0406: EGR position sensor voltage wrong.
P0412: The secondary air solenoid control circuit seems bad (this is used for the aspirator).
P0420: The catalyst seems inefficient (#1).
P0432: The catalyst seems inefficient (#2).
P0441: Evaporative purge flow system not working properly
P0442: A leak has been detected in the evaporative system!
P0443: Evaporative purge flow system solenoid not working properly
P0455: A large leak has been detected in the evaporative system!
P0456: A small leak has been detected in the evaporative system!

P046x – Fuel Level Sensor

P0460: The fuel level sender is not reporting any change over a long distance. Something seems wrong.
P0461: The fuel level sender is not reporting any change over a long time. Something seems wrong.
P0462: Fuel level sender voltage wrong.
P0463: Fuel level sender voltage wrong.

P05xx – Vehicle Speed Controls and Idle Control System

P0500: Haven’t heard from the speed sensor lately.
P0505: The idle speed air control motor doesn’t seem to be working correctly.
P0522: Oil pressure sensor problems
P0523: Oil pressure sensor problems
P0551: The power steering switch may not be working. (Neons: high pressure is showing up at high speed)

P06xx – Computer Output Circuit

P0600: Oh-oh! The coprocessors aren’t talking to each other within the computer!
P0601: Internal computer error!
P0604: Internal computer error! (RAM check)
P0605: Internal computer error! (ROM)
P0615: Starter relay circuit problem
P0622: Generator field control problem
P0645: A/C clutch relay circuit problem.

P07xx – Transmission

P0700: The automatic transmission computer or Aisin computer has a problem – ask it what’s going on. I don’t know.
P0703: Brake switch circuit information seems wrong.
P0711: Based on the transmission temperature and its operations, it looks like the transmission temperature sensor’s gone bad.
P0712: Transmission fluid temperature sensor voltage wrong.
P0713: Transmission fluid temperature sensor voltage wrong.
P0720: The Output Shaft Speed Sensor doesn’t match the reported vehicle speed.
P0740: The engine’s running faster than it should for these speeds, so I think the torque converter clutch lock-up system is bad
P0743: Torque converter clutch (part throttle unlock) solenoid circuit problem – shift solenoid C electrical fault
P0748: Governor Pressure Solenoid circuit problem (Transmission relay circuit problem in Jeep RE transmissions)
P0751: Overdrive override switch has been pressed for over five minutes. Just thought you should know.
P0753: Overdrive solenoid control circuit problem (transmission relay circuit in Jeep RE transmissions.)
P0756: Shift solenoid B (2-3) fault
P0783: The overdrive solenoid can’t go from 3rd gear to the overdrive gear.
P0801: Transmission reverse gear lockout solenoid circuit problem!
P0833: Problem with the clutch-released switch circuit?

P11xx – Manufacturer Specific Enhanced Codes

P1192: Inlet air temperature sensor voltage is wrong
P1193: Inlet air temperature sensor voltage is wrong
P1194: Oxygen sensor heater performance is faulty (Bank 1 Sensor 1)
P1195: Oxygen sensor is slow (Bank 1 Sensor 1)
P1196: The oxygen sensor switched too slowly (bank 2).
P1197: The oxygen sensor switched too slowly (bank 1).
P1198: Radiator coolant temperature sensor voltage is wrong.
P1199: Radiator coolant temperature sensor voltage is wrong.
P1281: The engine is staying cold too long – check your thermostat.
P1282: The fuel pump relay circuit seems to be having a problem.
P1288: The intake manifold short runner tuning valve circuit seems to be having a problem.
P1289: There’s a problem in the manifold tuning valve solenoid control circuit.
P1290: Compressed natural gas system pressure is too high
P1291: The heated air intake sensor does not seem to be working.
P1292: Natural gas pressure sensor issue
P1293: Natural gas pressure sensor issue
P1294: Can’t get to target engine speed, check for vacuum leaks and idle speed motor issues.
P1295: The throttle position sensor doesn’t seem to be getting enough electricity.
P1296: The MAP sensor doesn’t seem to be getting enough electricity.
P1297: The MAP sensor doesn’t change its reading when the engine is running!
P1298: During wide-open throttle, the engine runs lean.
P1299: MAP Sensor and Throttle Position Sensor signals don’t match, check for a vacuum leak.
P1388: Auto shutdown relay circuit problems?
P1389: No Z1 or Z2 voltage seen by the computer when the auto shutdown relay is used.
P1390: Cam and crank signals don’t match – did the timing belt skip a tooth?
P1391: Sometimes, I can’t see the crank or cam sensor signal.
P1398: I can see the Crank Sensor’s signal when I prepare for Misfire Diagnostics. Try replacing it.
P1399: Problem in the Wait to Start Lamp circuit – (diesels only?)
P1403: EGR position sensor not getting (enough) voltage.
P1476: Too little secondary air injection during aspirator test.
P1477: Too much secondary air injection during aspirator test.
P1478: Battery temperature sensor voltage wrong.
P1479: Transmission fan relay circuit problems?
P1480: PCV solenoid circuit problems?
P1481: Transmission RPM pulse generator signal for misfire detection seems wrong.
P1482: Catalyst temperature sensor circuit shorted low.
P1483: Catalyst temperature sensor circuit shorted high.
P1484: The catalyst seems to be overheating!
P1485: Air injection solenoid circuit problems.
P1486: Pinched or blocked hose in the evaporative hose system.
P1487: Control circuit of the #2 high-speed radiator fan control relay is having problems.
P1488: Auxiliary 5-volt sensor feed is too low.
P1489: High speed radiator fan control circuit problem.
P1490: Low speed radiator fan control circuit problem.
P1491: Radiator fan control circuit problem (may be solid state relays as well as other circuits).
P1492: Ambient or battery temperature sensor voltage wrong
P1493: Ambient or battery temperature sensor voltage wrong
P1494: Leak Detection Pump (LDP) pressure switch problem – electrical or the pump itself.
P1495: Leak Detection Pump (LDP) pressure switch problem – the solenoid circuit.
P1496: Sensor feed is below an acceptable limit. (under 4v for 4 seconds – should be 5v).
P1498: High speed radiator fan control circuit problem. (#3 control relay)

P15xx – Idle Air Control System

P1594: Voltage too high in charging system.
P1595: Speed control vacuum or vent solenoid control circuits shorted or lost.
P1596: Speed control switch always high
P1597: Speed control switch always low
P1598: A/C pressure sensor voltage high
P1599: A/C pressure sensor voltage low

P16xx & P17xx – Network Communication & Transmission

P1681: No messages received from the cluster control module (dashboard computer).
P1682: Charging system doesn’t seem to be working well. Check alternator, etc.
P1683: Speed control servo power control circuit problem.
P1684: The battery has been disconnected within the last 50 starts.
P1685: Invalid key received from the Smart Key Immobilizer Module.
P1686: No messages received from the Smart Key Immobilizer Module.
P1687: No messages received from the Mechanical Instrument Cluster module.
P1693: The companion engine control module has shown a fault.
P1694: No messages received from the powertrain control module-Aisin transmission.
P1695: No messages received from the body control module.
P1696: Unsuccessful attempt to write to an EEPROM location!
P1697: Unsuccessful attempt to update Service Reminder Indicator (SRI or EMR) mileage!
P1698: No messages received from the electronic transmission control module or the Aisin transmission controller.
P1719: Transmission 2-3 gear lockout solenoid control circuit problem.
P1740: Either the tcc solenoid or overdrive solenoid systems doesn’t seem to be making much sense.
P1756: Transmission control pressure not equal to target. (Mid pressure problem)
P1757: Transmission control pressure not equal to target. (Zero pressure problem)
P1762: The Governor Pressure Sensor input was too high or too low for 3 consecutive park/neutral calibrations.
P1763: The Governor Pressure Sensor input is too high
P1764: The Governor Pressure Sensor input is too low.
P1765: Open or short in the Transmission Relay control circuit.
P1899: The Park/Neutral switch seems to be stuck!

Conclusion

Understanding the OBD2 codes for your 1996 Jeep Grand Cherokee is a vital first step in diagnosing and resolving vehicle issues. By using either the key trick method or an OBD2 scanner, you can quickly access these codes and begin to understand potential problems. This guide provides a comprehensive list of codes to help you interpret the readings.

Remember, while this information is helpful for preliminary diagnosis, it’s crucial to consult with a certified mechanic for accurate diagnosis and repairs. OBD2 codes are valuable tools, but professional expertise ensures your 1996 Jeep Grand Cherokee receives the best possible care. This knowledge empowers you to communicate effectively with your mechanic and make informed decisions about your vehicle’s maintenance.