Unable to start the car

Tiny
MAMIRORO SMITH
  • MEMBER
  • 2002 FORD FOCUS
  • 2.0L
  • 4 CYL
  • AUTOMATIC
  • 150,000 MILES
After I ground the valves, I could start the car. I attempt to carry out scanning but failed to communicate. PCM is not communicating with scanner. The major issue. Thanks
Friday, October 6th, 2023 AT 9:46 AM

68 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,217 POSTS
Hi,

Does the scan tool power up when connected to the DLC? Was this an issue prior to the valve job?

As far as the communication issue, first, check pin 16 in the DLC for battery voltage. It should be present at all times.

If that is good, check pins 4 and 5 in the DLC for a ground path (continuity to ground).

See pic below of the DLC. I highlighted the connectors to check.

Let me know what you find.

Take care,

joe

See pic below.
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Sunday, October 22nd, 2023 AT 9:24 PM
Tiny
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Good day, thanks very much for the kind assistance. I tried to measure the 5v ref of the TPS and the value fluctuates between 0.22 to 0.24. I checked for battery voltage pin 16 and got 0.02. When I plugged in the scanner, it powered up but reads linking error, failed to communicate. When I turned the ignition, the attached video was displayed on the cluster panel. What should I do next?
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Thursday, October 26th, 2023 AT 9:37 AM
Tiny
JACOBANDNICKOLAS
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Hi,

Pin 16 should have 12v (B+ voltage). Did you check the fuse? It is fuse 48 in the central junction box inside the vehicle. See pics below. That power is sent to the DLC directly from the fuse, so there isn't a module controlling it. If you only have 0.02v, that is a problem.

Let me know about the fuse.

Take care,

joe

See pics below.
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Thursday, October 26th, 2023 AT 7:32 PM
Tiny
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Good day sir, I guess I wasn't doing it right before now. So, I got 12.4 volts at pin 16 of the DLC. As for checking for the grounds in pin 4 and 5, I disconnected the battery and turned the knob to 2k 20k 200k 2M ohms. I was getting varying fluctuating values in all of them. I don't know which of them will produce accurate value or how to test for ground (continuity). The 5v ref remains at 0.22 to 0.27 thanks for your assistance. I am glad you help. What should I do next?
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Friday, October 27th, 2023 AT 10:03 AM
Tiny
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I also don't know how to use the voltmeter to test fuse because none of the fuse I tested produce any value when the knob was turned to 20 mA except just one. Which is 0.03.
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Friday, October 27th, 2023 AT 10:10 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

If you are checking power at the fuses, you can use a test light. If you do use a multimeter, it shouldn't be set on mA. That is milliamps. That is for a much lower voltage. Set it on a standard amperage setting. Check the setting at the battery. When you find the setting that shows 12v, that is the one to use.

Also, here is a link that explains how to test a fuse. It will help you through the process.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

As far as the TPS voltage, it shouldn't be that low. Take a look at pic 1 below and let me know if you are comfortable performing it. It explains how to test for voltage at the connector itself. I also attached the connector pinout, so you know which ones to check.

Let me know.

Joe

See pics below.
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Friday, October 27th, 2023 AT 8:47 PM
Tiny
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Greetings,

I appreciate all you do. In testing for the 5v ref, I placed the red lead in the SIG RTN and VREF, got same value. The value is even dropping. I use the chassis as ground, same response. I might be getting the testing right. I think that is where the issue lies. The PCM not communicating with the DLC. What are the possible test I can do to detect this short. What should I be looking at. I believe this the image of the TPS. Thank you very much for your concern and help.
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Sunday, October 29th, 2023 AT 11:00 PM
Tiny
MAMIRORO SMITH
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The TPS please.
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Sunday, October 29th, 2023 AT 11:06 PM
Tiny
JACOBANDNICKOLAS
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Hi,

First, I attached a pic below showing where to check for a 5v reference signal. See pic 1. Use your multimeter and connect one probe to one pin and the other probe to the other pin. With the key in the run position (engine off), see how much voltage is present. It should be between 4v and 6v. If it still is very low, then either we have a wire issue, a connector problem, or the PCM is faulty.

Pic 2 is from what you sent me. Have you tried cleaning it? I ask because the throttle body. Bore and the throttle plate have a special coating applied during manufacture which should not be removed. It looks exceptionally dirty, and it also appears there are two bolts missing (circled with blue) (TPS circled with red).

Let me know.

Joe

See pics below.
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Monday, October 30th, 2023 AT 6:06 PM
Tiny
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Good morning, sir,

At your suggestion, I have gotten a new PCM with programmed keys. However, I want to find out the cause of the short first before installing it in order to avoid damaging the new one. I don't think at any time I have cleaned the throttle body. Should I do that because I have intentions of detailing the whole engine if the car can start running. I want to get the service of a technician that might assist. My major concern now is the wires. I also observed that I can't remove the key after I turned on the ignition until I disconnect the battery. There is box I don't know its functioning but looks like the security. I don't know if it is contributing to the issue. Thanks very for the keen interest and God bless you richly.
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Monday, October 30th, 2023 AT 11:09 PM
Tiny
JACOBANDNICKOLAS
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Hi,

In your last picture, where is that located? It looks like someone wired that in place using electrical tape.

As far as the short, before you remove the PCM, locate the power supply connector at the module and check if power is present at the module. If it isn't, I suspect the short is internal in the module itself.

Let me know.

Joe

See pic below.
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Tuesday, October 31st, 2023 AT 6:07 PM
Tiny
MAMIRORO SMITH
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The car has active antitheft. There is a small button I used to click and then turn on the ignition before I start the car. I don't know if this antitheft comes with all model of the car or the dealer I bought the car from install it himself. I think the click button is wired to this box but don't know where this box is wired to. Can I ask what is pin on the PCM to check the power supply. Thanks very much for your concern and time. God bless you in many ways
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Tuesday, October 31st, 2023 AT 11:48 PM
Tiny
JACOBANDNICKOLAS
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Hi,

The switch wouldn't be a factory option. Someone added that to the vehicle. As far as a power supply to the ECM/PCM, it is provided via fuse 20 in the battery junction box. It is a 10-amp fuse.

I attached the wiring between the ECM/PCM and that fuse. The connector pin is 55 in connector C. The wire is red in color.

Let me know.

Joe

See pics below. Note: Fuse 20 should have battery voltage at all times.
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Wednesday, November 1st, 2023 AT 5:57 PM
Tiny
MAMIRORO SMITH
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Good day sir, I can now test the fuses using voltmeter, fuse 20 is okay. Fuse 30 and 40 didn't give any reading. I couldn't locate pin 55 on the PCM. Still thinking about the possible cause of the short. If the 5v ref is so low, maybe injector or ETC won't get any. Thanks very much for your efforts, I still look forward to your contributions. Thanks once again and God bless you
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Saturday, November 4th, 2023 AT 10:31 AM
Tiny
JACOBANDNICKOLAS
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Hi,

Fuses 30 and 40? One is the light switch, and the other is the back-up lamps. (CJB). See pic below.

As far as pin 55, does the connector look differently than the one I attached above?

Let me know.

Joe

See pic below.
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Saturday, November 4th, 2023 AT 8:19 PM
Tiny
MAMIRORO SMITH
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Greetings boss, the fuse 30 and 40 I am referring to is in the BJB. Maybe that is the rating. What I mean by locating the pin 55 is if it could be cycle on the image just like the pin 16 of DLC for easy identification. I can't place the transceiver ring round the key cylinder. Does it in any way affect the readings and output at the PCM. As part of the development of the whole problem. When the low oil pressure and battery charging was indicating in the cluster illumination. The headlamps stopped working. I experienced hard starting then. As of now, I feel it was because of the short issue, they stopped working and radiator fans weren't working then too. I would like to resolve those issues as well. I contracted a technician who will be on ground on Tuesday. I also want to be guided to avoid repeated flaws. Thanks once again and I remain grateful.
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Sunday, November 5th, 2023 AT 12:23 PM
Tiny
MAMIRORO SMITH
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Circle it on the image of the PCM connector.
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Sunday, November 5th, 2023 AT 12:51 PM
Tiny
JACOBANDNICKOLAS
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Hi,

I copied my pic from above. Let me know if that helps.

Take care,

Joe
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Sunday, November 5th, 2023 AT 8:58 PM
Tiny
MAMIRORO SMITH
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Good day sir, there is light at the end of the tunnel. I tested fuse 30 and 40 in CJB. One is okay while the other reading maximum reading is 0.18 volt. The fog light turned on, a glimpse of hope. I tried the test at the pin 55 of the PCM, no reading at all. If it happens that the wire is the issue going by this, what should I do? What are the grounds and splices attached to the PCM harness that could be a possible source of short. Why is there no reading? Is it that I didn't perform it correctly? I didn't place the transceiver ring, but I did it with ignition off and on. Thank you very much and God bless you.
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Monday, November 6th, 2023 AT 11:33 AM
Tiny
MAMIRORO SMITH
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The fog light.
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Monday, November 6th, 2023 AT 11:45 AM

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