Ecu bad?
Thread Starter
|
Post Fiend
Joined: Jun 2005
Posts: 7,047
Likes: 2
From: North west La
Ecu bad?
I have been trying to repair my 97s Evap system. My fuel pressure senser went bad in my tank. I think it fryed my ECU. It says this is possible when this senser fails. My ecu has been throwing evap codes PO452 since I replaced the senser. It also stalls at startup sometimes & the cel comes on but it will run fine if I kill it & restart it. It doesn't store the code when it does this & the light goes off when I restart it. Is there a way to test the ecu? Thanks
Senior User
Joined: Aug 2003
Posts: 166
Likes: 0
From: Hurricane Alley
I do not think there is anyone that tests the ECU. At the same time, I do not think it is your ECU but, it could be. It may be the chip in your ECU, which does not come with the ECU when you purchase it to the best of my knowledge. New, or remanuractrured, doesn't matter. Check and see what it costs to buy a replacement, knowing that it is not returnable. Same goes with the chip, but that is dealer item only in that case. Or, find a used one....check Ebay...I know I have seen them for about $20 used and about $60 "rebuilt", so to speak.....
Other than that......if a sensor goes bad....it goes bad. I can not see how a bad sensor can fry the ECU....unless there is a direct short in it and Ford didn't build protection into the ECU for just that type of issue, which is unlikely.
Other than that......if a sensor goes bad....it goes bad. I can not see how a bad sensor can fry the ECU....unless there is a direct short in it and Ford didn't build protection into the ECU for just that type of issue, which is unlikely.
Hotshot
Joined: Jan 2004
Posts: 19,763
Likes: 1,081
From: St Louis
Here's what the service CD says about the P0452:
Please note that the sensor is used only for testing of the evaporative emissions system. It is not used in any way for the "normal" operation of the truck.
Does your scanner have the capability of reading PIDs? If so, you can read the actual measured voltage at the PCM input and can test the PCM input circuitry.
Alternatively, you can disconnect the FTP, jumper the output line to Vref, run KOEO, and see if you can force a P0453 code.
Steve
Diagnostic Trouble Code (DTC) P0452 indicates that Self-Test has detected an FTP circuit input below minimum.
Possible causes:
-- Fuel tank pressure (FTP) sensor completely submerged in liquid fuel.
-- Inside contamination of the electrical connector on the FTP sensor.
-- FTP short to SIG RTN or PWR GND.
-- Damaged FTP sensor.
-- Damaged PCM.
l Key off.
l Visually check for liquid fuel contamination of the FTP sensor electrical connector.
l Check for completely submerged FTP sensor in liquid fuel (can affect correct FTP voltage reading).
l Does FTP sensor and its electrical connector show signs of fuel contamination?
Yes
REPAIR FTP sensor electrical connector as necessary. ADJUST fuel tank overfill. COMPLETE PCM Reset to clear DTCs. RERUN «Quick Test».
No
GO to «HX27».
Possible causes:
-- Fuel tank pressure (FTP) sensor completely submerged in liquid fuel.
-- Inside contamination of the electrical connector on the FTP sensor.
-- FTP short to SIG RTN or PWR GND.
-- Damaged FTP sensor.
-- Damaged PCM.
l Key off.
l Visually check for liquid fuel contamination of the FTP sensor electrical connector.
l Check for completely submerged FTP sensor in liquid fuel (can affect correct FTP voltage reading).
l Does FTP sensor and its electrical connector show signs of fuel contamination?
Yes
REPAIR FTP sensor electrical connector as necessary. ADJUST fuel tank overfill. COMPLETE PCM Reset to clear DTCs. RERUN «Quick Test».
No
GO to «HX27».
Please note that the sensor is used only for testing of the evaporative emissions system. It is not used in any way for the "normal" operation of the truck.
Does your scanner have the capability of reading PIDs? If so, you can read the actual measured voltage at the PCM input and can test the PCM input circuitry.
Alternatively, you can disconnect the FTP, jumper the output line to Vref, run KOEO, and see if you can force a P0453 code.
Steve
Last edited by projectSHO89; Feb 14, 2006 at 06:42 AM.
