Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2001 Jeep Wrangler SE, AutomaticFACTORY OEM SERVICE PROCEDURE

Diagnostic Trouble Code Definitions

DTC MESSAGES & CODES

Generic Scan Tool Code ⁽¹⁾

DRBIII(R) Scan Tool Message

O2 SENSOR HEATER CIRCUIT LOW 1/1

O2 SENSOR HEATER CIRCUIT HIGH 1/1

O2 SENSOR HEATER CIRCUIT LOW 1/2

O2 SENSOR HEATER CIRCUIT HIGH 1/2

O2 SENSOR HEATER CIRCUIT LOW 2/1

O2 SENSOR HEATER CIRCUIT HIGH 2/1

AMBIENT TEMP SENSOR PERFORMANCE

MAP SENSOR VOLTAGE TOO LOW

MAP SENSOR VOLTAGE TOO HIGH

INTAKE AIR TEMP SENSOR VOLTAGE LOW

INTAKE AIR TEMP SENSOR VOLTAGE HIGH

ECT SENSOR VOLTAGE TOO LOW

ECT SENSOR VOLTAGE TOO HIGH

TPS VOLTAGE DOES NOT AGREE WITH MAP

THROTTLE POSITION SENSOR VOLTAGE LOW

THROTTLE POSITION SENSOR VOLTAGE HIGH

CLOSED LOOP TEMP NOT REACHED

1/1 O2 SENSOR SHORTED TO GROUND

1/1 O2 SENSOR SHORTED TO VOLTAGE

1/1 O2 SENSOR SLOW RESPONSE

1/1 O2 SENSOR HEATER FAILURE

1/2 O2 SENSOR SHORTED TO GROUND

1/2 O2 SENSOR SHORTED TO VOLTAGE

1/2 O2 SENSOR SLOW RESPONSE

1/2 O2 SENSOR HEATER FAILURE

2/1 O2 SENSOR SHORTED TO GROUND

2/1 O2 SENSOR SHORTED TO VOLTAGE

2/1 O2 SENSOR SLOW RESPONSE

2/1 O2 SENSOR HEATER FAILURE

2/2 O2 SENSOR SHORTED TO GROUND

2/2 O2 SENSOR SHORTED TO VOLTAGE

2/2 O2 SENSOR SLOW RESPONSE

2/2 O2 SENSOR HEATER FAILURE

1/1 FUEL SYSTEM LEAN

1/1 FUEL SYSTEM RICH

2/1 FUEL SYSTEM LEAN

2/1 FUEL SYSTEM RICH

INJECTOR #1 CONTROL CIRCUIT

INJECTOR #2 CONTROL CIRCUIT

INJECTOR #3 CONTROL CIRCUIT

INJECTOR #4 CONTROL CIRCUIT

P0205 ⁽⁴⁾

INJECTOR #5 CONTROL CIRCUIT

P0206 ⁽⁴⁾

INJECTOR #6 CONTROL CIRCUIT

MULTIPLE CYLINDER MISFIRE

CYLINDER #1 MISFIRE

CYLINDER #2 MISFIRE

CYLINDER #3 MISFIRE

CYLINDER #4 MISFIRE

P0305 ⁽⁴⁾

CYLINDER #5 MISFIRE

P0306 ⁽⁴⁾

CYLINDER #6 MISFIRE

NO CRANK REFERENCE SIGNAL AT PCM

NO CAM SIGNAL AT PCM

P0351 ⁽⁵⁾

IGNITION COIL #1 PRIMARY CIRCUIT

P0351 ⁽⁴⁾

IGNITION COIL #1 PRIMARY CIRCUIT

P0352 ⁽⁴⁾

IGNITION COIL #2 PRIMARY CIRCUIT

P0353 ⁽⁴⁾

IGNITION COIL #3 PRIMARY CIRCUIT

1/1 CATALYTIC CONVERTER EFFICIENCY

2/1 CATALYTIC CONVERTER EFFICIENCY

EVAP PURGE FLOW MONITOR FAILURE

EVAP LEAK MONITOR MEDIUM (.040") LEAK DETECTED

EVAP PURGE SOLENOID CIRCUIT

EVAP LEAK MONITOR LARGE LEAK DETECTED

EVAP LEAK MONITOR SMALL (.020") LEAK DETECTED

FUEL LEVEL UNIT NO CHANGE OVER MILES

FUEL LEVEL UNIT NO CHANGE OVER TIME

FUEL LEVEL SENSOR VOLTS TOO LOW

FUEL LEVEL SENSOR VOLTS TOO HIGH

NO VEHICLE SPEED SENSOR SIGNAL

IDLE AIR CONTROL MOTOR CIRCUITS

OIL PRESSURE SENSOR VOLTS LOW

OIL PRESSURE SENSOR VOLTS HIGH

P0551 ⁽⁵⁾

POWER STEERING SWITCH FAILURE

INTERNAL CONTROLLER FAILURE

P0622 ⁽⁶⁾

GENERATOR FIELD NOT SWITCHING PROPERLY

A/C CLUTCH RELAY CIRCUIT

P0740 ⁽⁷⁾

TORQ CONV CLU, NO RPM DROP AT LOCKUP

P0743 ⁽⁷⁾

TORQUE CONVERTER CLUTCH SOLENOID/TRANS RELAY CKT

SLOW 1/1 O2S DURING CATALYST MONITOR

SLOW 2/1 O2 SENSOR SLOW DURING CATALYST MONITOR

ENGINE IS COLD TOO LONG

FUEL PUMP RELAY CONTROL CIRCUIT

TARGET IDLE NOT REACHED

NO 5 VOLTS TO MAP SENSOR

NO CHANGE IN MAP FROM START TO RUN

AUTO SHUTDOWN RELAY CONTROL CIRCUIT

NO ASD RELAY OUTPUT VOLTAGE AT PCM

INTERMITTENT LOSS OF CMP OR CKP

MISFIRE ADAPTIVE NUMERATOR AT LIMIT

EVAP LEAK MONITOR PINCHED HOSE FOUND

AMBIENT/BATT TEMPERATURE SEN VOLTAGE TOO HIGH

AMBIENT/BATT TEMPERATURE SEN VOLTAGE TOO LOW

LEAK DETECTION PUMP SW OR MECHANICAL FAULT

LEAK DETECTION PUMP SOLENOID CIRCUIT

P1594 ⁽⁶⁾

CHARGING SYSTEM VOLTAGE TOO HIGH

P1595 ⁽⁸⁾

SPEED CONTROL SOLENOID CIRCUITS

P1596 ⁽⁸⁾

SPEED CONTROL SWITCH ALWAYS HIGH

P1597 ⁽⁸⁾

SPEED CONTROL SWITCH ALWAYS LOW

P1682 ⁽⁶⁾

CHARGING SYSTEM VOLTAGE TOO LOW

P1683 ⁽⁸⁾

SPEED CONTROL POWER RELAY CIRCUIT OR S/C 12V DRIVER CIRCUIT

INVALID SKIM KEY

NO SKIM BUS MESSAGE RECEIVED

NO CLUSTER BUS MESSAGE

PCM FAILURE EEPROM WRITE DENIED

P/N SWITCH PERFORMANCE (A/T)

⁽¹⁾	Perform appropriate test under DIAGNOSTIC TESTS.

⁽²⁾	Test only applies to 2.5L and 4.0L with Federal emissions.

⁽³⁾	Test only applies to 4.0L with Calif. emissions.

⁽⁴⁾	Test only applies to 4.0L.

⁽⁵⁾	Test only applies to 2.5L.

⁽⁶⁾	This DTC is related to charging system. For diagnostic procedure, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.

⁽⁷⁾	This DTC is related to automatic transmission diagnostics. For diagnostic procedure, see appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS.

⁽⁸⁾	This DTC is related to cruise control system diagnostics. For diagnostic procedure, see appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.

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