NOTE: For XJ6 models, additional codes not listed in this article have been updated as per TSB SECTION 18, No. 3 - Faulty Fuel Systems: New Feedback Fault Codes.

TROUBLE CODE IDENTIFICATION

No.	System Affected	Probable Cause
12	Mass Airflow (MAF) Sensor	Not In Operating Range
14	Coolant Temp. Sensor	Not In Operating Range
16	Air Temperature Sensor	Not In Operating Range
17	Throttle Position Sensor	Not In Operating Range
18	Throttle Potentiometer/MAF Sensor	Resistance Low at WOT
19	Throttle Potentiometer/MAF Sensor	Resistance High At Idle
22	Heated O2 Sensor/Fuel Pump Relay	Open Or Short Ckt @ Idle
23	Fuel Control	Rich Exhaust Indicated
24	Ignition Amplifier	Open Or Short Circuit
26	Air Leak/Running Lean	Lean Exhaust/Vacuum Leak
29	Electronic Control Module	Self Check
33	Fuel Injector Circuit	Open Or Short Circuit
34	Fuel Injector Circuit	Faulty Injector
37	EGR Solenoid Valve	Short Or Open Circuit
39	EGR Function	Faulty System Operation
44	Heated Oxygen Sensor	Rich Or Lean Condition
46	Idle Air Control Valve (Coil 1)	Open Or Short Circuit
47	Idle Air Control Valve (Coil 2)	Open Or Short Circuit
48	Idle Air Control Valve Position	Not Within Specification
66	Air Injection Pump Relay	Short Circuit Or Faulty Pump
68	Vehicle Speed Sensor	Incorrect Signal Voltage
69	Park/Neutral Position Switch Ckt	Engine Cranks In Drive
89	EVAP Canister Purge Control Valve	Voltage Out Of Range

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.

Safety Warning

Trouble Code Definition (DTC) Identification

Use the Manual With the Right Hardware

When to See a Mechanic

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