How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Randall C Your Own Question

Randall C
Randall C, ASE MasterTechnician
Category: Ford
Satisfied Customers: 11327
Experience:  35 years ASE Master Tech, Diagnostic , Electrical Specialist
13677702
Type Your Ford Question Here...
Randall C is online now
A new question is answered every 9 seconds

2005 ford explorer limited: the check charging system light will come

Resolved Question:

I have an 2005 ford explorer limited. I'll be driving and I'll hear a beeping sound and the check charging system light will come up on the memo screen. I've had the battery and aternator checked and it's good. What do you think may be wrong. The battery picture will light up in red when this message appears.
Submitted: 4 years ago.
Category: Ford
Expert:  Randall C replied 4 years ago.
Chat Conversation Started
Tracer :

Hello, is the vehicle nearby that you can get me the 8th digit of the VIN # XXXXX we look at correct engine? You read the VIN from the left. the VIN is on dash, drivers side, base of windshield? I need the 8th digit from left. LMk when you can. thanks

Customer:

hold on

Tracer :

no problem

Customer:

1fmzu75k65ua61685

Tracer :

For the future if asked, you have a 4.0 litre engine Flex fuel engine. Thanks. Let me check a couple things. back shortly

Customer:

ok

Tracer :

did parts store check battery and alternator or a shop? was the test done with alternator in vehicle?

Customer:

yes

Customer:

it was checked at advanced autos and they said it was working correctly

Customer:

we also had a garage check the alternator and battery and they said it was working properly

Customer:

said the alternator was recently replaced

Tracer :

Thanks. i am going to do a bit of typing so bear with me. I will give you all the info you need to know. Coming next :)

Tracer :

Does the light/message come on and stay on all the time or.. once in awhile it comes on?

Customer:

it comes on once in awhile

Customer:

the other day i was taking my son to football practice and it came on at least 10 times

Tracer :

Thanks. Will send info next

Customer:

ok

Tracer :

In older vehicles the charging was just battery and alternator. in alot of todays vehicles, like yours, the alternator is controlled by the PCM ) powertrain control module) "computer" . You could drop into most any shop and the alternator tests ok but.. the PCM has detected a problem and may not be alternator or battery at all. I never like to tell customers this but.. you could have a PCM going bad. the other thing is the shop MUST test alternator when light/message is on. If not, it will pass all tests. the next step unfortunatley is to have a shop hook a full system scanner. they can view PCM data and charge data as well. Yes,, it may be charging all the time and you will have no problems even with light on but the light means something has been detected. It can not be ignored. if older truck, i would say bad alternator but your vehicle is different. The PCM controls the regulator inside the alternator. It can be a little tricky to diagnose when problem/light occurs. yes, you could? have PCm going bad. rare? yes, but can happen. below is a very formal description of the charging system in technical terms.

Tracer :

Powertrain Control Module (PCM) Controlled Charging System

Overview

The PCM-controlled charging system provides many additional benefits over the current integral generator regulator system. The first benefit is improved battery life. In an integral generator regulator system the regulator set point is established by a temperature sensor in the regulator which estimates battery temperature. In a PCM-controlled charging system the regulator voltage set point is determined by the PCM and communicated to the regulator through the generator regulator control (GENRC) circuit. The PCM uses an algorithm to estimate battery temperature. Improving baffery temperature estimates will reduce battery damage caused by over- and undercharging.

The second benefit is improved engine performance. Whenever the PCM senses a wide- open throttle (WOT) condition the PCM will momentarily lower the regulator voltage set point. This reduces the torque load of the generator on the engine and improves acceleration. The PCM has a calibratable time limit on this reduced voltage feature. This is to prevent the generator output from being cut back for an extended WOT period which could cause battery discharge.

The third benefit is improved idle stability. In response to the PCM's GENRC signal the regulator uses a generator load input (GENLI) signal to provide feedback to the PCM. The GENLI signal provides the PCM with charging system information. Specifically it lets the PCM know when the charging system receives a transient electrical load which would normally affect idle stability. Because the PCM can anticipate additional loads actions can be taken to minimize idle sag. The PCM can choose to either reduce the regulator set point or increase engine idle speed~ both of which are calibratable features. In order to establish whether the regulator is accurately maintaining the desired voltage set point~ the regulator uses a charging system voltage line to sense battery voltage.

The fourth benefit is reduced cranking efforts. The PCM can reduce the mechanical load on the starter by initially commanding a low voltage set point. This may improve start times.

If the PCM detects a charging system error it will broadcast a low voltage telltale (ON) network communication message which tells the cluster to illuminate the charge indicator. The charge indicator will be illuminated if the PCM fails to see a signal on the GENLI circuit for a time period greater than 500 milliseconds. This telltale command will also be used to indicate over-voltage conditions detected by the PCM-controlled generator.

Each time the ignition switch is cycled to the run position the instrument cluster will initiate a bulb check by illuminating the charge indicator. It is the PCM's responsibility to issue a low voltage telltale (OFF) command if the charging system is functioning properly. This message should be sent during the network initialization in the voluntary phase (250 milliseconds to 450 milliseconds after the ignition switch is cycled to the run position). If a low voltage telltale (OFF) network communication message is not received the instrument cluster will continue to illuminate the charge indicator indefinitely.

Customer:

how much does this part cost

Customer:

the pcm for my type of vehicle

Customer:

i just bought it off from a used car lot. I only had it for two weeks and this is already showing up. I still have a 30 day warranty on the vehicle

Customer:

i would like to get this replaced if i can. i have the vehicle financed through the bank for 48 months. Can this be fixed? Or did I buy something that's unrepairable?

Tracer :

By no means can i say this is the problem 100% but by your description and tests done so far, it is looking like possibility. Since alt was changed one time before, someone may have been chasing a problem. the PCM new is not cheap. May? be able to find aftermarket but hard to match #'s/. each area prices different so my info may not be at 100%accurate but should be close. labor is nothing, its the part

Tracer :





























Engine Control Module
ECM
Auto Trans5U7Z12A650BJA$869.98










Order By Stamp Number.





















LaborSkill
Level
Mfg.
Warranty
Standard
Engine Control Module
ReplaceB0.50.6

Customer:

Thank you Tracer, I have talked to several people and searched on the internet if anyone else has had this problem and it's the same thing that you mentioned to me. I appreciate the help. Thanks,

Randall C, ASE MasterTechnician
Category: Ford
Satisfied Customers: 11327
Experience: 35 years ASE Master Tech, Diagnostic , Electrical Specialist
Randall C and 8 other Ford Specialists are ready to help you

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • AlvinC answered a question about my Ford truck that only someone with an in-depth knowledge of his subject would have known what was going on. Rich D USA
< Last | Next >
  • AlvinC answered a question about my Ford truck that only someone with an in-depth knowledge of his subject would have known what was going on. Rich D USA
  • Because of your expertise, you armed me with enough ammunition to win the battle with the dealer. They are installing a fuel filter and fuel pump at no charge to me. Molly USA
  • I needed help with my car on Saturday morning....got a response in 5 minutes, and it was the perfect solution. Thanks again to your service. Jason V. Kirkland, WA
  • I do know, after going though this with JustAnswer, that I can somewhat trust my mechanic but I will always contact you prior to going there. BR New Jersey
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
 
 
 

Meet The Experts:

 
 
 
  • Ron

    ASE Certified Technician

    Satisfied Customers:

    20942
    23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
< Last | Next >
  • http://ww2.justanswer.com/uploads/FO/fordguy4u/2011-12-17_222940_HPIM1257.64x64.JPG Ron's Avatar

    Ron

    ASE Certified Technician

    Satisfied Customers:

    20942
    23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka- Moose)'s Avatar

    Chris (aka- Moose)

    Ford Technician

    Satisfied Customers:

    22382
    16 years experience with Ford.
  • http://ww2.justanswer.com/uploads/JM/jmcdo28/2012-2-23_01655_resized.64x64.jpg John Mc's Avatar

    John Mc

    Ford Technician

    Satisfied Customers:

    5493
    19 years Ford Lincoln Mercury experience
  • http://ww2.justanswer.com/uploads/wmarti7/2009-4-18_04332_Avatar.jpg Chuck's Avatar

    Chuck

    ASE Certified Technician

    Satisfied Customers:

    1684
    33 Years Experience,Ford Senior Master,ASE Master,L1 Advanced Engine Performance
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    1518
    12 years at a Ford Lincoln/Mercury and Jaguar dealer as a technician and shop foreman.
  • http://ww2.justanswer.com/uploads/BA/baddad1/2014-4-1_23659_avatar.64x64.jpg Mike V.'s Avatar

    Mike V.

    Auto Service Technician

    Satisfied Customers:

    789
    25 years experience on all makes and models, Licensed NYS Inspector.
  • http://ww2.justanswer.com/uploads/lostrider/2009-9-26_23144_php4VNWAA_c1PM1.jpg lostrider's Avatar

    lostrider

    Ford Technician

    Satisfied Customers:

    2940
    ASE Master Technician, Ford Senior Master Technician,Diesel certified, ASE Master, 22 yrs FORD exp.