5.4L OBD Code P1451
Moderator
Joined: Dec 2001
Posts: 22,436
Likes: 17
From: Louisville,Ky.
The EVAP system monitors the canister vent (CV) solenoid circuit for an electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified canister vent duty cycle by PCM command.
A code P1451 may mean that one or more of the following has happened:
* VPWR circuit open
* Damaged canister vent solenoid
* Canister vent solenoid circuit open or shorted to ground, power, etc.
* Damaged Powertrain Control Module (PCM)
* Verify canister vent solenoid - To verify normal functioning, monitor the EVAP canister vent solenoid signal PID EVAPCV and the signal voltage (PCM control side). With the valve open, EVAPCV indicates 0% duty cycle and a voltage approximately equal to battery voltage. When the valve is commanded fully closed, EVAPCV indicates 100% duty cycle, and a minimum voltage drop of 4 volts is normal. Output test mode may be used to switch output on/off to verify function.
* Replace canister vent solenoid
A code P1451 may mean that one or more of the following has happened:
* VPWR circuit open
* Damaged canister vent solenoid
* Canister vent solenoid circuit open or shorted to ground, power, etc.
* Damaged Powertrain Control Module (PCM)
* Verify canister vent solenoid - To verify normal functioning, monitor the EVAP canister vent solenoid signal PID EVAPCV and the signal voltage (PCM control side). With the valve open, EVAPCV indicates 0% duty cycle and a voltage approximately equal to battery voltage. When the valve is commanded fully closed, EVAPCV indicates 100% duty cycle, and a minimum voltage drop of 4 volts is normal. Output test mode may be used to switch output on/off to verify function.
* Replace canister vent solenoid
Thread Starter
|
New User
Joined: Jul 2005
Posts: 10
Likes: 0
From: Northeast Pa.
I tested the cv sensor and got 54 ohms. I then tested the wiring harness from the cv sensor which showed only 2.59 volts. Do you think its a short, or should I pull the pcm and test the related pins?
Hotshot
Joined: Jan 2004
Posts: 19,760
Likes: 1,078
From: St Louis
It's probably not a short. It is far more likely that it is a bad connection, usually due to corrosion in the connector, causing a high resistance circuit.
What wire did you measure that on (there are two at the solenoid) and was that with the solenoid connected or not?
Steve
What wire did you measure that on (there are two at the solenoid) and was that with the solenoid connected or not?
Steve
Last edited by projectSHO89; Mar 8, 2006 at 08:44 AM.
Thread Starter
|
New User
Joined: Jul 2005
Posts: 10
Likes: 0
From: Northeast Pa.
I stuck my voltmeter in both wires at the solenoid connection wire harness. Then I checked the ohms at the solenoid connection. Will this code make the truck run any different? Thanks
Thread Starter
|
New User
Joined: Jul 2005
Posts: 10
Likes: 0
From: Northeast Pa.
Trending Topics
Hotshot
Joined: Jan 2004
Posts: 19,760
Likes: 1,078
From: St Louis
Measure from each pin to ground separately with the solenoid connected. With the solenoid de-energized, you should measure battery voltage on both wires. With the solenoid energized, you should show battery voltage on the R wire and near 0 Vdc on the P/W wire.
The CV solenoid is only for the evap emissions system. It won't affect engine operation. If you have emissions testing requirements where you live, it will automatically fail.
Steve
The CV solenoid is only for the evap emissions system. It won't affect engine operation. If you have emissions testing requirements where you live, it will automatically fail.
Steve
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
lgeiger13
Modular V8 (4.6L, 5.4L)
31
Jul 22, 2016 10:53 PM
dstewart5
1983 - 2012 Ranger & B-Series
2
May 8, 2007 07:09 AM
