Cadillac Seville / Cadillac Eldorado Forum Discussion, 97 Eldorado P 0441 in Past Cadillac Vehicle Discussion; I have a 97 Cadillac Eldorado with this code: P0441. After some research I replaced the purge solenoid. And now ...
I believe he means this. (P0441 Evaporative Emission (EVAP) System No Flow During Purge.) I found this in the forum I hope it helps it was on a 96 Fleetwood. DTC P0441 Evaporative Emission (EVAP) System No Flow During Purge
This diagnostic test is used to determine if the Evaporative Emission (EVAP) purge control solenoid is open when the PCM is commanding it open (energized). The PCM does this by monitoring the Evaporative Emission (EVAP) purge vacuum switch which is a normally closed switch mounted in the vacuum line between the EVAP canister and the EVAP purge solenoid. The switch opens when vacuum from the engine draws the evaporative emissions from the EVAP canister through the EVAP purge solenoid and into the throttle body. The PCM monitors the state of the EVAP purge vacuum switch to determine if the EVAP purge solenoid is open and passing vacuum. The PCM accomplishes this by monitoring the amount of time the EVAP purge vacuum switch is continuously open or closed during purge. When the test conditions are met the PCM starts a timer, which will be reset when the switch transitions open to closed or vice versa. If the switch remains closed for 9 seconds continuously, DTC P0441 is set. If the switch remains open for 2 seconds continuously, the test is passed.
Conditions for Setting the DTC
DTCs P0101, P0102, P0103, P0107, P0108, P0122, P0123, P0401, P0506, P0507, P1441, P1508, P1509 and P1645 not set.
IAT at key ON is greater than -25°C (-13°F).
IAT remains below 99.5°C.
ECT at key ON is at least 30°C less than previous key OFF ECT reading.
ECT is less than 125°C (257°F).
MAP is between 29.9 and 60 kPa.
Throttle position between 0 and 81.6 degrees.
Engine speed between 500 and 6375 RPM.
EVAP purge solenoid duty cycle at least 60%.
BARO at least 72.
Engine vacuum at least 12 kPa.
EVAP purge vacuum switch closed for 9 seconds and the EVAP purge vacuum switch has not been open for 2 seconds at any point during the test.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.
Conditions for Clearing the MIL/DTC
The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
A Last Test Failed DTC will clear when the diagnostic runs and does not fail.
A History DTC will clear after forty consecutive warm-up cycles with no failures of any diagnostic test.
Use a scan tool to clear DTCs.
Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.
Do not apply voltage to the EVAP vacuum switch. The voltage supplied by the PCM is of a low current design. The EVAP vacuum switch may be damaged if jumpered to voltage without this current limiting feature.
EVAP System Charcoal Contamination Checking Procedure
Remove EVAP Purge solenoid and the EVAP vacuum switch. Refer to R&R Procedures .
Lightly tap both components on a hard surface.
Check for the release of charcoal from either component.
If charcoal contamination is present replace the EVAP Vapor canister, EVAP Purge solenoid, EVAP Vacuum switch and clean the EVAP purge hoses. Refer to the EVAP Purge Hose Cleaning Procedure .
Number(s) below refer to the step number(s) on the Diagnostic Table.
Ensuring correct vacuum line connection and checking if fault conditions are present.
Checking if fault is vacuum or switch.
With a properly operating system the vacuum gauge can fluctuate rapidly while the solenoid is commanded On until 100% duty cycle is reached, at which point the vacuum should indicate the value specified. If the vacuum gauge indicates manifold vacuum immediately following 10% commanded On duty cycle then there is a restriction in the line or canister.
Evaporative Emission Control System Incorrect Purge Flow
What does that mean?
This indicates that a part of the EVAP control system is no longer functioning correctly. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.
EVAP emission canister purge is controlled by a valve which allows engine vacuum to pull stored fuel vapors from fuel tank into the engine to be burned, rather than be vented to atmosphere. A vacuum switch is used to detect when flow exists. If the PCM commands purge and sees that the switch is closed (indicating no detected purge flow) P0441 is set.
Likely, no symptoms will be discernible to the driver, other than the illuminated Check Engine Light.
A code P0441 could mean one or more of the following has happened:
•Bad vacuum switch
•Broken or damaged EVAP line or canister
•Open in PCM purge command circuit
•Open or short in Voltage feed circuit to Purge Solenoid
•Faulty purge solenoid
•Restriction in EVAP solenoid, line or canister
•Corrosion or resistance in purge connector
With a P0441 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:
•Common Chrysler fix - Replace Leak Detection Pump / LDP
•Repair damaged EVAP lines or canister
•Repair open or short in voltage feed circuit to Purge Solenoid
•Repair open in PCM purge command circuit
•Replace purge Solenoid
• Replace vacuum switch
•Repair restriction in Evap line or canister or solenoid
• Repair resistance in purge connector