2003 Jeep Grand Cherokee OBD2 Codes: Your Ultimate Diagnostic Guide

Understanding the diagnostic system in your 2003 Jeep Grand Cherokee is crucial for maintaining its performance and longevity. The On-Board Diagnostics II (OBD2) system is a powerful tool that can help you identify potential issues before they become major problems. This guide will help you navigate the OBD2 system in your 2003 Jeep Grand Cherokee, understand how to retrieve diagnostic trouble codes (DTCs), and interpret what these codes mean.

Understanding OBD2 Systems in Your 2003 Jeep Grand Cherokee

The introduction of OBD2 in the mid-1990s marked a significant advancement in automotive diagnostics. For 2003 Jeep Grand Cherokees, this system is designed to monitor various vehicle systems, including the engine, transmission, emissions controls, and more. When the system detects a problem, it illuminates the “Check Engine Light” (CEL) or “Service Engine Soon” light on your dashboard and stores a corresponding DTC in the vehicle’s computer.

OBD2 is standardized across all makes and models sold in the United States since 1996, ensuring a consistent approach to vehicle diagnostics. This standardization means that regardless of the brand, the basic principles of retrieving and interpreting OBD2 codes remain the same. For owners of a 2003 Jeep Grand Cherokee, this is particularly helpful as it allows for easier troubleshooting and repair, whether you’re a seasoned mechanic or a DIY enthusiast.

Retrieving OBD2 Codes on Your 2003 Jeep Grand Cherokee

There are two primary methods to retrieve OBD2 codes from your 2003 Jeep Grand Cherokee: using a scan tool and the “key trick” method.

Using an OBD2 Scan Tool

The most straightforward and recommended method is to use an OBD2 scan tool. These tools range from basic code readers to advanced professional-grade scanners.

Locate the OBD2 Port: The OBD2 port in a 2003 Jeep Grand Cherokee is typically located under the dashboard on the driver’s side. It’s a 16-pin connector, usually easily visible and accessible.
Connect the Scan Tool: With the ignition turned off, plug the OBD2 scan tool into the port.
Turn Ignition to “ON” Position: Turn the ignition key to the “ON” position without starting the engine.
Follow Scan Tool Instructions: Power on the scan tool and follow the manufacturer’s instructions to read codes. Typically, you’ll select options like “Read Codes” or “Diagnostic Codes.”
Record the Codes: The scan tool will display any stored DTCs. Record these codes for later interpretation.

Using a scan tool provides the benefit of not only reading the codes but often also providing a brief description of the code and allowing you to clear codes after repairs are made. More advanced scan tools can offer live data streaming, allowing you to monitor sensor readings in real-time, which can be invaluable for diagnosing intermittent issues.

The “Key Trick” Method for OBD2 Codes

While less informative than using a scan tool, the “key trick” can be used on a 2003 Jeep Grand Cherokee to display OBD2 codes on the odometer. This method utilizes the vehicle’s built-in diagnostic capabilities.

Ensure Ignition is OFF: Make sure the ignition is completely off.
Turn Key to “ON,” “OFF,” “ON,” “OFF,” “ON”: Within five seconds, cycle the ignition key from “OFF” to “ON” three times, ending in the “ON” position. “ON” is the position right before starting the engine; “OFF” is not “LOCK” but the position where the engine is off, but accessories can still function.
Observe the Odometer: After the key cycling sequence, the odometer display will go through a series of tests, displaying numbers from 111111 to 999999, then the vehicle’s VIN. Following this, if there are any stored DTCs, they will be displayed on the odometer, often starting with a “P” (for Powertrain codes).
Record the Codes: Note down any codes displayed. The code “P0123” would typically appear as “P0123” on the odometer. The code “55” or “done” usually indicates the end of the diagnostic code output and that no further codes are stored.

This method is useful when a scan tool is not immediately available. However, it only provides the numeric codes without descriptions, making interpretation require looking up the codes manually.

Decoding OBD2 Error Codes for Your 2003 Jeep Grand Cherokee

OBD2 codes are five-digit alphanumeric codes. Understanding the structure of these codes can be helpful:

First Character: Indicates the system:
- P – Powertrain (Engine, Transmission)
- B – Body (e.g., windows, airbags, central locking)
- C – Chassis (e.g., ABS, brakes, suspension)
- U – Network/Communication (e.g., CAN bus)
Second Character: Indicates code type:
- 0 – Generic OBD2 code (standard across all manufacturers)
- 1, 2, 3 – Manufacturer-specific code (enhanced codes specific to Jeep/Chrysler)
Third Character: Indicates the subsystem:
- 1 – Fuel and Air Metering
- 2 – Fuel and Air Metering (Injector Circuit)
- 3 – Ignition System or Misfire
- 4 – Auxiliary Emission Controls
- 5 – Vehicle Speed Controls and Idle Control System
- 6 – Computer Output Circuit
- 7, 8 – Transmission
Fourth and Fifth Characters: Specific fault within the subsystem.

For a 2003 Jeep Grand Cherokee, most engine-related codes will start with “P.” Below is an extensive list of OBD2 and some OBD1 codes that may be relevant to your vehicle, compiled from various sources. Please note that while this list is comprehensive, it may not be exhaustive, and accuracy is not guaranteed due to the varied sources. Always consult official repair manuals for definitive information.

Older Model Computer Codes (OBDI) – IMPORTANT! Codes may be different for newer vehicles starting circa 1996.

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 62 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)

P0030 Sensor heater relay problem
P0036 Sensor heater relay problem
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 temparature 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 temparature and switch to energy-efficient mode
P0130 Sensor heater relay problem
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 (this device helps to reduce emissions more quickly)
P0151 Oxygen sensor voltage problem – short circuit to ground?
P0152 Oxygen sensor voltage problem – short circuit to active 12V?
P0153 Oxygen sensor response too slow
P0154 Oxygen sensor does not show either a rich or lean condition – may need replacement
P0155 Oxygen sensor heater element not working properly (this device helps to reduce emissions more quickly)
P0157 Oxygen sensor voltage problem – short circuit to ground?
P0158 Oxygen sensor voltage problem – short circuit to active 12V?
P0159 Oxygen sensor response too slow
P0160 Oxygen sensor does not show either a rich or lean condition – may need replacement
P0161 Oxygen sensor heater element not working properly (this device helps to reduce emissions more quickly)
P0171 The oxygen sensor is saying that the system air/fuel mix is far too lean (too much fuel is being added as a correction).
P0172 The oxygen sensor is saying that the system air/fuel mix is far too rich (too much air is being added as a correction).
P0174 The oxygen sensor is saying that the system air/fuel mix is far too lean (too much fuel is being added as a correction).
P0175 The oxygen sensor is saying that the system air/fuel mix is far too rich (too much air is being added as a correction).
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
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)
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
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!
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.
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)
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.
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 thetorque convertor 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?
P1192 Inlet air temperature sensor voltage is wrong
P1193 Inlet air temperature sensor voltage is wrong
P1194 Oxygen sensor heater performance is faulty
P1195 Oxygen sensor is slow
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)
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
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!

DISCLAIMER: This code list is for informational purposes only and should not be used as a definitive repair guide. The information is compiled from various sources, and accuracy is not guaranteed. Diagnosing and repairing vehicle issues requires expertise and should be performed by qualified professionals. This list is intended to aid in preliminary troubleshooting, not to replace professional diagnostic procedures. Always consult a certified mechanic for diagnosis and repairs.

Troubleshooting and Repair Tips Based on OBD2 Codes

Once you have retrieved the OBD2 codes from your 2003 Jeep Grand Cherokee, the next step is to understand what these codes indicate and how to proceed with troubleshooting.

Research the Codes: Use reliable online resources or repair manuals to get detailed descriptions of each code. Websites like cardiagnosticnearme.com often provide in-depth information about OBD2 codes and their potential causes.
Understand Potential Causes: OBD2 codes are designed to point you in the direction of a problem, but they don’t always pinpoint the exact fault. For example, a code indicating an oxygen sensor issue might be caused by a faulty sensor, but also by vacuum leaks, exhaust leaks, or issues with other components affecting the sensor’s readings.
Prioritize Multiple Codes: If you have multiple codes, address the most critical ones first. Sometimes, one primary issue can trigger a cascade of related codes.
Start with Basic Checks: Before replacing any parts, perform basic visual inspections. Check for loose gas caps (common cause of EVAP system codes), vacuum leaks, disconnected wires, and corroded connectors.
Use Live Data (with Scan Tool): If using a scan tool that offers live data, monitor relevant sensor readings. This can provide valuable insights into sensor performance and system operation. For instance, watching oxygen sensor voltage fluctuations can help determine if a sensor is genuinely faulty or reacting to another problem.
Component Testing: Depending on the code, you may need to test specific components. A multimeter, vacuum gauge, and other diagnostic tools can be used to test sensors, actuators, and circuits.
Consult a Professional: If you are uncomfortable with diagnostics or repairs, or if the problem is complex, it’s always best to consult a certified mechanic. Misdiagnosis and improper repairs can lead to further issues and increased costs.

Important Considerations:

Clear Codes After Repair: After addressing the issue, use a scan tool to clear the DTCs and turn off the Check Engine Light.
Verify the Repair: After clearing codes, drive your Jeep Grand Cherokee under conditions that previously triggered the code to ensure the problem is resolved and the code does not return.
Regular Maintenance: Regular maintenance, including timely oil changes, air filter replacements, and spark plug replacements, can help prevent many OBD2 related issues.

Conclusion

The OBD2 system in your 2003 Jeep Grand Cherokee is a valuable diagnostic tool. By understanding how to retrieve and interpret OBD2 codes, you can take a proactive approach to vehicle maintenance and address potential problems early on. Whether you choose to use the key trick method or invest in a scan tool, this guide provides you with the essential information to start diagnosing issues with your 2003 Jeep Grand Cherokee. Remember, while OBD2 codes offer a starting point, accurate diagnosis and repair often require professional expertise. For reliable diagnostics and repair services, consider visiting cardiagnosticnearme.com to find qualified professionals near you.