03 MACH 1 CCRM BUZZING/ CLICKING

aedirtbikex3

New Member
Mar 18, 2010
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Hey I encountered a problem the other day, and is driving me crazy

I rebuilt the rear in my car, put 4.10s in it, and I took the diablo tune off because i ordered a bama tuner.
Well had the car running for an hour or so to check the coolant and see how it sounded backing up and down the drive way.
well drove it 5 miles and the car shuts off and the CCRM is buzzing, a clicking noise or buzz. I was luckily able to drive it back home, but i noticed my O2 sensor plug was unplugged so I plugged that back up
But now the car will not start and the CCRM is buzzing still
I bought a new CCRM, still buzzes, I tested them in my freinds 03 mach 1 and it works fine, no buzzing.

The THEFT light is blinking rapidly and the scanner can't read the car, Says failure to read car, or turn the key to the on position but do not start.

Any ideas or where to start?

any help is greatly apperciated!
 
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Can you measure the voltage across the battery terminals?

Can you then measure from the battery "positive" to a point on the chassis and then to a point on the engine (cylinder head, for example)?

Sounds like you've got a low system voltage or a bad ground connection.
 
Thank you for response.
I measured the battery, it gave 11.9-12.1, it jumped bewteen those numbers.
I Then did what you said and measured from the positive to the engine. I also got the same numbers. 11.9-12.1, I measured to the headers, radiator, intake, heads, valve covers bolts all gave 11.9-12.1,
I know the CCRM is good, it worked fine in my freinds car.

What fuses could i check, i checked them and only found the cigarette fuse was bad, But some fuses didnt show any volts, i replaced them with new fuses and still didnt sh ow anything but that could be the blinkers werent on right?

Are there any special ones for the CCRM
 
Also, when i plug my scanner into the car to find engine codes, it says that it can't read the car, that i need to turn the key to the on position but don't start the car, and i do that, still not able to read the car
 
Okay, I will check tomorrow once I get back from school, around 3 p/m
So if the headlights are on, and the car not started, wont the current generally be lower since no altenator to back it up to 12 v?
I know the radio is working normal, Ill do measurements, one with just headlights on and another with radio and headlights on,
 
The CCRM is basically an enclosure with relays inside. You could visualize a relay as a coupled electromagnet and switch. A relatively small current (~0.2 Amp) will activate the electromagnet which in turn operates the switch. The switch can handle 20-30 Amps (in some cases, a lot more), so the fundamental function of a relay is to permit a small current to control a much larger current.
What Trinity_GT (and I) think may have happened is your alternator is marginal, and idling the engine for a prolonged period has run down the battery. A discharged battery may still have ~12V across the terminals without a load current, but that voltage will drop subtantially under load.

So, what's with the buzzing CCRM?
When you turn on the ignition, one or more of the electromagnets (relays) in the CCRM becomed activated. This closes the coupled switch(es), which connect the battery to critical loads (example: perhaps 10-15 amps for the fuel pump). But, when the controlled large currents begin to flow, battery voltage drops to less than ~8V, and the electromagment consequently releases the switch. This breaks the large current, and the electromagnet voltage goes back up to ~12V re-energizing it. This cycle keeps repeating as long as the ignition is on, resulting in a buzzing or repeated clicking sound as the electromagnet(s) turn on and off.

Measuring the battery voltage during this event will often yield a slightly low voltage (11 to 12.3) that is unstable.

Turning on the headlights and taillamps will cause a constant load of ~10 amps to flow. If the battery voltage drops substantially, that result supports the aforementioned theory. Even if there is no change in battery voltage, you could have a poor connection anywhere between the battery and CCRM, and still have the identical symptoms.
 
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BAD NEWSS!!! nothing worked.....
as in:

but in a different battery, hoping that would solve anything, it was 12.6 with no ignition key on; I then turn key on, its at 12.3 with the radio on. Then i turn on the headlights, its 11.8. so Im not to sure its the battery.

I cleaned every ground I could find. and cleaned the positive terminal from the altenator to the battery, I am just out of luck or guess's

(i did find an exposed wire from the o2 sensor, i have a new o2 sensor but can't get this one cracked, but i plugged my new o2 sesnor in to see if that would do anything, and still same old problems)

Now i put in the ECU i had, it was different serial number which i was told that it wont work in my car, but I am not 100% positive that this PCM worked b4, so its hard to say. I put it in and still was --------
And the buzzing was still there

I think im going to break down and buy a PCM/ECU that meets my serial number and have ford sync it and make me 2 new keys?

GOOD IDEA?? or anything else I should check b4 this
 
I'll admit it is possible that a new PCM/ECU will solve everything. But . . . it's an expensive part and might ot be the answer. I would at least first check all CCRM-related fuses to ensure the PCM/ECU is getting power with the key in the On position.

In your first post, you reported this scanner message: "Failure to read car, or turn the key to the on position but do not start.". This message suggests to me the scanner "thinks" the key is in the Off position, even when it is On. A bad fuse could cause this. And a frayed oxygen sensor heater wire that contacted the chassis could cause a fuse to open.

Here are some fuses to check. Measure from both ends of the fuse to chassis with the key On. There are usually slots at each end of the fuse where you can make contact with a voltmeter probe while the fuse remains in place.

F1.26 (engine compartment); 30A large size fuse; powers the PCM and CCRM.
F2.34 (fuse panel under the dash); 20A; powers the PCM and CCRM
F2.8 (fuse panel under the dash); 20A; powers the oxygen sensors
F1.14 (engine compartment); 20A; powers the CCRM
F2.2 (fuse panel under the dash); 20A; powers the CCRM and fuel pump

In all cases, the voltage at both ends of the fuse should be approximately equal to the voltage measured at the positive battery terminal (~12V). Fuse 2.34 is particularly suspect because it protects loads that are only powered with the key in the On position, specifically the imstrument cluster, passive anti-theft system, CCRM, and Ignition.

In your original post . . . were you able to drive some distance home with the CCRM buzzing/clicking the entire time? If yes, it means the fuel pump, fuel injectors, and ingition were all functioning, so at least part of the PCM/ECU was OK at that point.
 
I will double check the fuses again and make sure the correct fuses are in the correct spot, when i put the car together, I wasnt able to get a cover for the fuse box for under the dash. so is this link an acceptable one to go off of?

http://mustangforums.com/forum/4-6l-1996-2004-modular-mustang/548199-2003-gt-fuse-box-diagram.html

Well i thought it was my rear end but my car felt like it wasnt getting enough air and then stalled, I pulled over and heard the buzzing from the CCRM, I waited there about 20mins until i got antifreeze and made sure I wasn't low, but it wasnt, so I started the car back up and drove 5 miles home with no problems and parked it, then came to start it the next day and it sits where i parked it

I will check the fuses in a few hours, at work now.
Ford said it would cost 125 for a new key, and 35 for a spare, so 160 for 2 keys, and they said it should sync the new PCM with the key n IC, Found a PCM for 250, so might try this out. Might give it a gamble if these fuses check out okay
 
if that fuse diagram was correct, then i found a problem.....
fuse numbers had no volt reading, or very little less then 1, and i replaced the fuse and still got the same amount.

F2.35- powertrain control module (PCM), abs module, speed control servo, brake shift interlock
F2.41- multifunction switch, HIGH mounted STOP LAMP,


Now i did take out my REAR to install the gears because I have no lift and took about 30mins to take out, so I took out the ABS sensors in the rear. could that do anything?

if not where should I start
 
The linked fuse diagram matches the one in my '03 shop manual. I am posting one here for the engine compartment fuse/relay box.

F2.35 and F2.41 should only have power when the brake pedal is depressed.
Removing the ABS sensors should not cause your symptoms.

It's interesting you were able to start OK and drive ~5 miles when the engine was warm. It's another typical symptom of a poor electrical connection.

03MustangBJB_zps9dc989db.jpg
 
where should i start =[

ive done this so far due to another person recommending these on the PCM connection

Pin 16- (SCP+) = 12 vPin 15- (scp -)= ground/ 12v when plugged up to pin 16

checked the grounds for 25,3,51,77,103 and give full signal, the power pins (55,71,97) are all 12.47
 
Your friend gave you some good information. Those were the correct PCM power and ground pins. So the PCM seems to have power OK.

Let's start here:
Does the starter motor operate and crank the engine? According to the wiring diagrams, the PCM and PATS can prevent the engine from running by inhibiting spark and fuel injection, but does not disable cranking. Fuse 2.34 powers the PATS system.

If yes, was there +12V at both ends of fuse 2.2 and 2.8 with the key on? Yes means the PCM relay within the CCRM is working OK. It powers the engine controls via those fuses.
 
Well I listed this problem i had in another forumn and you both are helping me and giving me great info

I actually checked all of the fuses, all gave the 12v or varied 12 -12.5, so 2.2 and 2.8 are good, only ones that didnt have signal were
and yes the starter engauges, just cranks and cranks, no starting though

now 2.34 fuse that had 12v, wat would cause that to shut down, the security, bad connection(but i checked all those points so shouldnt that say its getting power to the PCM) , so maybe the key isnt being reconized? or instrument cluster? or the signal in the steering column?
 
I'm not sure if the CCRM buzz/click has anything to do with no-start, or is just a coincidence. After all, the car did start and run at least once after the clicking started.

When you mentioned 12V and 12.5V, did not mean some fuses measured different than others? A difference of 0.5V with a light battery load could be significant. If fuse 2.34 measures 12V while most others measure 12.5V, that could mean fuse 2.34 is receiving pulsing DC from the CCRM instead of a steady voltage. I don't know how the PATS system would react to this condition.

Are the CCRM connector terminals accessible for voltmeter measurements, or is it back behind the fender apron?
 
I checked, the fuses were all reading the same, volts on the pcm were all the same also..
the ccrm is easy to get to, i have the tire off and the plastic piece down a little,
what volt readings should I recieve from the CCRM.
 
CCRM voltage measurements:

Pin 24 (red) battery voltage with key On (PCM power)
Pin 12 (red) battery voltage with key On (fuel pump relay)
Pin 5 (dark green / yellow stripe) battery voltage with key On (fuel pump)
Pin 23 (black / yellow stripe) ~zero (A/C compressor clutch)
Pin1 or 2 (red / orange stripe) ~zero (low speed radiator fan)
Pin 6 or 7 (orange / light blue stripe) ~zero (high speed radiator fan)

The connector has 2 rows of 12 pins each (1 to 12 and 13 to 24).
Pins 1 (red / orange stripe) and 13 (white / blue stripe) are at one end of the connector.
Pins 12 (red) and 24 (red) are at the other end
There are no wires to Pins 9, 19, and 20.
 
which one are the grounds? now I think if i remember i checked the grounds on this. and I found out one was 12, and 2 were 8 volts. if there were 3 grounds, it was 2 days ago and was getting dark
I will double check tomorrow all grounds should be 12 when plugged to a 12v power correct?