JEEP GC 1999 P0443 EVAP SOLENOID CODE: Leak Fixed, Light Returns Immediately - No Click, No Voltage on Control Wire
I have a 1999 Jeep Grand Cherokee 4.7L with the engine light on. After identifying and fixing an evaporative emissions leak, I cleared the code, but it returns immediately. The vehicle has no performance issues—runs smoothly, no warning symptoms—and I’ve already replaced the PCM. Despite multiple attempts to resolve this, a local garage returned the vehicle without charge. I conducted comparative testing on two other 1999 Jeep Grand Cherokees with identical setups. In those vehicles, continuity from the purge solenoid to the PCM connector reads approximately 1.335 ohms across various pins. However, in my 1999 model, the same test shows only about 0.803 ohms on corresponding pins. I do not hear any clicking sound when the key is turned on. I confirm that both wires at the purge solenoid have 12 volts when the key is ON—however, when I attempt to ground either wire directly, there is no spark or response. The issue persists even after replacing the PCM. The vehicle cannot be inspected due to the recurring P0443 code. I am seeking advice on possible causes and diagnostics for this persistent EVAP system fault.
You fixed the leak—what exactly was it? \n\nPLEASE confirm: do you have a remote starter installed? (Yes/No) — THIS IS IMPORTANT. \nDid you replace the purge solenoid? (Yes/No) \n\nThe purge solenoid should show resistance between 30.0 and 40.0 ohms—did your test confirm this? (Yes/No) \n\nAt the solenoid, there are two wires: \n- DB/WT wire: 12V from ignition switch \n- PK/BK wire: control signal from purge solenoid to PCM \n\nWhen testing the circuit from the PCM to the EVAP purge solenoid connector, note that the control wire does not show voltage and is not grounded. Is the resistance between the two terminals of the solenoid below 5.0 ohms? \n\nIntermittent connections may be present—try shaking the harness during testing. \nI will also check for any relevant Technical Service Bulletins (TSBs) related to P044 or EVAP system failures in 1999 Jeep Grand Cherokee models.