Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Hello and welcome! My name is ***** ***** I can assist you with your question. Have you checked injector pulse using a noid light while cranking? Does the noid light blink while cranking?
Thank you for that information. Sorry I missed that part. What is the TPS voltage at key on engine off and while cranking?
NO, I am talking about the signal voltage. Not the reference voltage
The reason I ask is because you might just have a bad throttle position sensor.
I do believe it will be the gray and white wire. You will need to have the key turned ON, connector plugged into the TPS and back problem the gray/white wire to get a reading.
Is the throttle plate closed all of the way?
Normal closed throttle voltage of the TP sensor should indicate 0.6-1.1 volts. If the throttle plate is open or if the signal is too high when cranking, the PCM will put the engine in clear flood mode and it will not pulse the injectors. Was the TPS replaced? How about the PCM?
If your sure that the 5 volt reference is not shorted to ground, I would suspect a faulty input to the PCM. Did you check the powers and grounds?
If not, that would be your next step.
You can check the powers and grounds right at the PCM. I can send this information over shortly
The red wire going into pin 71 and dark green/orange wire going into pin 55 should have FULL battery voltage on them with the key on.
Would you be willing to speak on the phone?
I think this would be easier over the phone.. but there is an additional cost.
So no injector pulse and no power to the fuel pump while cranking.. correct?
Was the CCRM replaced?
I dont believe so. It is the contsant control relay module. Do you have power on the red wire going to the idle air control motor with the key on and cranking?
Ok no problem. In addition, if that checks out good, I want to see if the gray/red wire has power on it coming out of the CCRM with the engine cranking over.
I suspect thats our problem. Both need to have power leaving the CCRM when cranking provided I am reading the diagram correctly. Keep in mind, it needs to have the correct powers going into it in order to work.
There should be 6 wires going into the CCRM that have FULL battery voltage with the KEY ON
You want a picture of the CCRM?
Here is a pic of the CCRM
2 Dark blue wires, Orange wire, 2 Dark green/orange wires, and the white/light blue wire should all have battery FULL battery voltage on them with the key on.
Checking the inputs is going to be the next step.
Ok sounds good. Thank for checking for me. Was the CCRM replaced? It might just be bad..
Ok then you will need to figure out why that wire coming out of the CCRM does not have power on it while cranking
Try powering up that wire gray/red wire leaving the CCRM on pin 5 and see if the fuel pump comes up.
Hello and sorry for the delay! Does the engine start and run when you power up pin number 5 at the CCRM?
Ok, thank you for that information. The next step is to check all other inputs to the CCRM with the key on and while cranking.
Ok I will have to do some digging and post this information here in the morning.
You are welcome!
Just a heads up! I will have to do some digging monday morning and reply back then as my findings need to be during normal business hours. Talk to you monday!
Hello and sorry for the delay! Can you tell me if the PCM is activating the fuel pump relay when turning the key on or when cranking?
Right, thats what I want to see. The PCM is responsible for this. But you said it was replaced?
And is it installed in the vehicle?
But you can still access all of the wires going into the CCRM. That where we need to check.
Then we need to check that light blue and orange wire for a signal when turning the key on and while cranking.
With a voltmeter or a test light.
IT should change from 12 volts to ground or from ground to 12 volts as the key is turned on.
YES please verify all of the powers going into the module again as well as all of the grounds.
I would like you to check this and report back a to what you have found.
Here is a complete wiring diagram of the CCRM
So what does the blue/orange wire have on it key on and cranking? Power or ground?
So your saying that you grounded this wire and the fuel pump ran? Was the key on when you did this test?
The fuel injectors get a signal from the PCM.
YES, you need a scan tool that can read live data to see if there is engine rpm while cranking.
Does the check engine light STAY ON or GO OFF while cranking?
Are you sure about that?
The only other sensor that could cut off injector pulse while cranking that I am aware of would be a bad mass air flow sensor.
You cant really test it if the engine is not running. I would just try a new one
Or maybe disconnecting it.
Are you sure the anti theft or security light is on on or flashing when trying to start the engine? No anti theft codes in the computer?
Have you tried using another ignition key?
It should come on with the key on for a bulb check. Maybe the bulb is burned out
NO, no relearn procedure. The PCM needs to ground that light blue/orange wire (that I had you test earlier) when the key is turned on. If not, the PCM is at fault or there is a security issue going on. Hands down.
The dash should still have a theft light built into it. It should come on with the key on for a bulb check.
The PCM cuts the fuel pump and injectors when the anti theft is triggered.
Hello, my name is***** and thanks for your question.
All 97 Sables came with passive anti - theft. If the led is dead then that issue needs to be addressed before anything else, most likely the cause of the entire problem. Start by checking fuses 23 and 10 in the interior fusebox for power on both sides key in the run position. If those fuses have power on both sides then I would replace the PATS module located behind the radio panel. After replacement the keys will need to be programmed at the dealer or by using the method below:
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Passive Anti-Theft System (PATS) Control Module
Disconnect battery ground cable (14301). Refer to Section 14-01.
Remove integrated control panel. Refer to Section 12-03B.
Remove screw retaining passive anti-theft system control module to instrument panel (04320).
Disconnect electrical connector and remove passive anti-theft system control module.
Install passive anti-theft system control module. Tighten retaining screws to 3.4-4.8 Nm (30-42 lb-in).
Install an encoded ignition key (with correct vehicle mechanical key cut) into ignition switch and turn to RUN position to program the first key into control module using the 45 minute method.
To program additional keys, follow Spare Key Programming procedure as described.
It sounds like you have the problem under control and don't need expert advice. Though seeing that the pats led works when bypassed and both fuses that power the pats module have power has pretty much condemned the pats module in every way would lead me to replace it. If you want to continue down this road of replacing and substituting parts without any solid diagnosis then by all means continue on and best of luck!
If you had no power to the fuses then that would warrant further investigation as to why. You have a theft problem being that the light never works unless you jumper it. If the module has failed how can it light the light to indicate a problem?
new fuel pump-new spark plugs and wires
EEC box replaced, no change-ECM replaced with known good unit, no change
See diagram at link below.
Must of been a late build 96