So i bought the car about a month ago…it was driven about 200 miles home and then another 100 miles on 2 different occasions. Just last Friday i started it up and took it for a 25 mile run. everything was working perfectly. I parked it and went to start it monday but now it won't start. The battery is brand new. When you turn the key you can hear the starter click a few times and then nothing. all the electric comes on and works AC blows cold…the fan for the motor seems to turn on and run really hard. The engine doesn't seem to want to even try to turn over. I tried pumping the gas pedal nothing there. i thought maybe the ignition was the problem but the key does turn and i can move the steering wheel when the key is turned. Battery is brand new and i know nothing was left on in the car to drain it. You can hear the starter click so i don't think that is the issue…it has a full tank of gas…i tried 2 different keys in case it was a security issue with the key….any ideas?

Thanks

 

Check that the negative battery cable has a good connection to the car frame and that there is no corrosion.
This does not sound like an RCM issue, if you can hear the starter motor clicking.
A/C blows cold ? How could this be without the compressor turning ?
The only thing left is the 12v wire from the battery to the starter, the starter motor itself, or possibly the pulse module.

 

Maybe disconnect the battery for about 30 minutes and see if the car resets itself?

 

I did have this happen to me. I took the battery out to have it checked...if was good. When I reconnected it...everything was fine and it started???

 

Are you hearing the starter click or could it be relays you are hearing?

 

Good point DJ. Starter motors clunk more than they click.

 

The clicking you hear is most likely the starter solenoid. The way the circuitry works, when you trun the key to 'start', it energizes the starter solenoid coil. The solenoid has heavy duty contacts sufficient to carry the heavy current draw of the starter motor under load via their attachment to the battery. When you hear the clicking when you turn the key, you hear the solenoid pulling in it's contacts which supply current to power the starter motor. (the starter us usually grounded via its connection to the motor) If the starter motor does not respond and crank the engine via its gear mesh in the flywheel, then it seems therein lies your problem. Many things can be the problem: burned solenoid contacts; loose or coroded or dirty calbe from the battery to the solenoid contact. Weak starter motor etc.
Since modern starters are integrated with their solenoid It may be and often is that replacement of the starter/solenoid unit corrects the problem, since so doing usually exposes any cabling issues which may exist.
Now this is just my observation, to give you some perspective into your issue. It is also rudimentary, and not necessarily all that is involved in your issue with the crossfire. It may give you perspective when you discuss this issue with a professiional.

Rusty

 

OK that sounds like a bad connection or weak battery: what is happening is that the solenoid pulls about 10A. The linkage does two things:
1) engages the starter gear
2) when it bottoms contact is made between the disk and plunger which puts power to the starter motor. The starter pullls about 100A (varies with age and temp but close enough for illustration.

Ok what happens with a bad battery or wiring (something is probably getting hot and there you are) is that it can provide the 10A for the solenoid but when the disk hits the plunger (the click), the system cannot support the 100A & the voltage drops below the solenoid threshold and it resets. This removes the load, voltage returns, and if the key is stil at start the cycle starts again.

This is what causes the click, click, click... If there was just one click I'd say replace the starter but with many clicks the starter/solenoid is probably good and the battery or wiring is bad.

Simple.

ps if the problem was the battery terminal, R&Ring the battery may have fixed. Try starting when cold and see if either battery terminal or wire gets hot.

 

What both previous posters are overlooking here is that the key and the starter are not connected on our cars.
The key just tells the PTCM that you want to start the car.
The PTCM then checks a whole slew of things to make sure all the ducks are in a row, then tells the pulse module it is OK to engage the starter motor.
The pulse module is designed to engage the starter for sufficient time to cause at least 2 complete revolutions of the engine.
The PTCM monitors this via the CPS sensor, once it sees that the TDC indication has occurred twice, it then knows the position of the crankshaft and can make timing decisions. ( at this point, the PTCM also employs signals from the Camshaft Position Sensor to fine tune the timing )
Only at this point does it energize solenoids in the RCM to provide fuel and power for the ignition coils, and Houston, we have lift-off !

BTW: on the XF, you only have to bump the key to start position for a few milliseconds for all the above to occur. You don't need to hold it there until the engine is started.

and : the gas pedal is only a mechanism that moves a variable resistor that tells the PTCM what you would like the engine to do. ( actually, I think this is a PWM signal ( Pulse Width Modulation ))
It makes the decisions from there and controls the stepping motor in the throttle body to speed up / slow down the engine.
True "fly-by-wire" engineering.

 

Correct and well-put, my friend.

"In-a-nutshell", as it were?

 

Thank you all for the responses. It was a fuel sensor control. The dealer sent someone out and replaced it and now the car is running fine.

 

With that dissertation you have officially earned your Doctorate of Crossfire degree! From now and forever forward you are to be respectfully addressed as DOCTOR George!

So Dr. George . . . What can we learn from this? Is there such a thing as a "fuel sensor control"?? If so, where is it located and do we normally refer to it by some other name? Please unconfuse me about this . . .

 

Ya got me there. I have no idea what that would be, other than pure dealer bulls**t gibberish.
As far as I know, the RCM turns on the fuel pump, it does it's thing and the pressure to the fuel rail/injectors is regulated to 58-60 lbs/sq inch by the internal blow-by spring in the fuel filter. I know of no sensor involved in monitoring fuel pressure or flow.
One would think if there was such a thing, some data on it would be available at the OBD port and my UltraGuage would have a selection for it, but alas no.

 

Ditto! ...........

 

In the ole days, this was called 'fruppa-frup'. Just another way of parting person 'A' from a sum of transferrable type of valuables, to person 'B'.


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