Start Up Trouble Cooling Fan and Fuel Pump

[TNT_Tile]

I have a 2003 V6 and I am having a severe problem at start up with the electric cooling fans and the fuel pump. I seems that only during start up if the cooling fans come on the fuel pump does not. After the car sits with the fan on for a few minutes and they turn off the fuel pump comes right on and is putting 52 psi to the fuel rail. I can hear the pump turn on but it will not untill the fan goes off. I am wondering a few things that could help me in pinpointing the issue.

1. Should the fan turn on at start up or only after the car gets to temp.
2. How are the cooling fan and fuel pump tied together.
3. Can I control the cooling fan at start up untill the pump is up and running
4. How do I test the voltage to the fuel pump at start up

The start up issue becomes progressively worse in the cold weather so I'm not sure if the signal could possible be too weak with the cooling fan on. The car runs absolutly great and I have already replaced the spark plugs, coils, and battery. I do have engine codes but I am not sure of the numbers. I do have them listed in another post if it helps. Any DIY tips would be great I am desperatly trying to stay out of the dealership to correct the issue but would like to do so before it progresses into anythin else. Thanks

 

[joegr]

1. If the climate control is on, then the fan will come on at startup. Otherwise, it should wait until the engine warms up.

2. They're both commanded by the PCM. They both tie into the electrical system very close to the battery. They do not run through any common fuses. It looks they only meet at the main battery cable.

3. Only by disconnecting the control connector at the fan. That will probably cause a check engine light.

4. The fuel pump is variable voltage drive. The REM drives it at variable voltage levels as commanded by the PCM to maintain the correct fuel pressure. If you have a Ford specific OBDII scan tool, you can monitor the percentage drive to the fuel pump as well as the fuel pressure. (You can also monitor the fan speed.) The green orange wire coming out of connector C420d on the REM is the power wire to the fuel pump. The brown red wire is the ground to the fuel pump. The diagram is not 100% clear as to which power wire into the FEM feeds the fuel pump circuit. It hints at it being the orange black wire on C420c, but it might be one of the two red orange wires instead.

This assumes that there weren't any changes to this between 2003 and 2004, which might not be true.

 

[TNT_Tile]

Climate Control and Everything inside is off and fan still comes on. My machanic has scan tool but it will not interface. I'll check again with him this weekend. I guess from reading other posts that getting the system flashed may help. Not sure if any sensors could be leading to the cooling fan turning on at start up. The issue seems to become worse in the colder weather or after the car has set for an extended period of time. I do have a small power steering leak from what I believe is the return line pressure sensor. May be coincidental. I'll have to get the codes and readings this weekend but the fuel pump is at 52 psi after the fan goes off and you can hear it turn on after the fan has already shut down. The fun part is knowing what is wrong and having no idea how to go about fixing it.

 

[joegr]

You may have some sort of PCM fault.
There are no pressure sensors or valves on the return line. The return line runs from the rack to the reservoir. A suction line runs from the reservoir to the pump, also without sensors. The pressure line runs from the pump to the rack and it has a pressure switch on it.

 

[TNT_Tile]

Must be the pressure line. Pcm fault sounds like something the dealer is going to have a go at. Getting colder and more diffulcult to start in the morning. Just unpluged the cooling fan this morning and it started right up with out a problem. Waited for car to hit temp and plugged it back in. Don't want to keep on doing it but it works for now. I think it is time to break down and take it into the dealer.

 

[TNT_Tile]

Wondering if anyone had any ideas of cost of pcm or how to go abouut fixing the start up issue. Also not sure where it is located.

 

[TNT_Tile]

any ideas would be helpful. Still unable to figure the issue out. Not sure if going to junk yard is an option and what to get to replace if I did. Thanks. Dealer will most likely charge an arm and a leg to diagnose even though I know what is wrong, just not why.

 

[TNT_Tile]

PCM Bump.... Condition only occurs when it is cold outside. Other then moving down south anyone have any ideas of if it is possible to bring in pcm over night or modular overnight to keep warm.

 

[joegr]

PCM Bump.... Condition only occurs when it is cold outside. Other then moving down south anyone have any ideas of if it is possible to bring in pcm over night or modular overnight to keep warm.

Is it because the PCM is cold, or more likely because one or more temperature sensors are cold? I've put a scan tool on and read the temperatures from all the temperature sensors and see if one of them is incorrect.

 

[TNT_Tile]

have to try and track down a ford conection. Machanic works out of his house, not garage. Doesn't have a tool that conects to the lincoln for some reason. Works on his explorer but will not read my car. He has the OBII but will not connect. Have to look around but will check before paying out. Thanks. Hey anyone in south jersey/philly area?

 

[joegr]

have to try and track down a ford conection. Machanic works out of his house, not garage. Doesn't have a tool that conects to the lincoln for some reason. Works on his explorer but will not read my car. He has the OBII but will not connect. Have to look around but will check before paying out. Thanks. Hey anyone in south jersey/philly area?

He probably has a non-CAN scanner. Anyway, you need a Ford specific scan tool, not a generic OBD-II scanner to get to the actual sensor values.

 

[TNT_Tile]

definatly generic, man has saved me thousands of dollars over the years and I repay him in any type of help I can offer. Not sure if autozone does the tool rental program for ford specific tool. Thanks for all the help. Have a loaner car for the week to try and get through but morning start up is killing me. Frustrating that car runs perfectly other than start up and will come on nearly immediatly when warmed in the sun. Hate to drop the dollars on it for something that I have overlooked but I am out of ideas.

 

[TNT_Tile]

OK. After all the headaches and guessing of what could possibly be wrong the official Lincoln verdict is in. A bad cell in my battery caused the PCM to wipe itself out. Diagnostic was $150, reprogramming PCM is another $60 putting me at $210. Also calling to replace the battery running me up to $320 or $330 for core if I want to keep old battery. Sounds like battery is an up charge but considering old one is from 2003 original I don't think I am going to lose on it. Allowed Lincoln to do everything they wanted to do so the same issue should not occur again. Already knew the PCM thing but didn't want to have it done on a guess. Thanks for all the help along the way. On a side note, anyone ever hear of a bad battery cell or was the coil problem more likely the cause of the PCM issue?

 

[TNT_Tile]

Update on Lincoln saga. Check engine light back on after 4 days. New code is P0430 Catalyst efficiency low-bank 2. PCM was reflashed and new battery so I am thinking just a coincidence that new issue appeared after being in dealership.

My new concern is as follows:

Recently had 2003 LS in shop for PCM issue. After looking everything over the dealer informed me the PCM needed reflash caused by a bad cell in the battery. Authorized dealer to install new battery on there word but requested old battery be saved since it was less than a year old. Battery was a bosch aftermarket that I installed in factory location with adapter for vent tube in the trunk. Paid the core deposit and went to get the battery tested before I raised hell at Pepboys over the bad battery. Auto Zone checked battery and Pepboys. Both places stated battery is 100% good. CCA tested higher then stated.

Should I go back to dealer and raise all He#@? Some how I have purchased two batteries in a year and I am thinking some one is wrong. Any ideas on how to fully test cells? Any advice would be appreciated. Thanks.