WADVR

So long story short: jumper cables went on backwards and am trying to get this thing going again.

The ASD relay isn't functioning properly as the ground signal from the PCM isn't either strong enough or not producing it. The meter shows no continuity to ground but does provide a ground path to show 12v when tested with the positive battery terminal. The relay shutters and will only allow 5 volts on the ASD output. I jumped the PCM supplied ground at the relay connector to negative battery post and the ASD works and the engine starts without issue. So this issue I need to find out why the PCM is not providing the ground signal. I have rung out this wire to the PCM connector and the 2 PCM ground wires to the coil mount and all are ok with solid continuity.

The alternator is pushing 16.9 volts continuously. The PCM regulates the voltage which sounds like yet another circuit from the PCM not pushing the ground to the alternator to regulate the alternators output. I am confused on this procedure so I might have it backwards and have wishfully thinking that both these problems have the same solution.

I have swapped the crank position sensor with a known good unit as well as the PCM with the same results. I also get a p1694 code and have tested the bus wires to the TCM and those are ok as well so is it possible a faulty TCM is creating this issue? Sometimes the check engine light is on and others not. I was able to drive it with these issues but it took some effort to start and keep going for the 1st few minutes each time. Once it is running it runs fine without any issues other than when I figured out it was being overcharged(gauge on dash was still reading just slightly higher than 14)

Any idea where to go from here?

CCKen

Lots of data to absorb there mate...

1st, Jumping the battery wrong has cooked PCMs and diode packs in alternators.

Did you say you replaced the PCM?

Voltmeter on instrument cluster reading just above 14 volts is okay provided the reading comes down to just above 13 volts after the battery gets charged.

You can check the ground cicuit for the ASD relay (and other relays) control coil in the following manner (refer to the relay base image):

Remove the relay and using a voltmeter, measure the voltage from relay pin cavity 85 to battery ground - with key OFF, you should see approximately 0.02 volts, and with key in RUN (engine off) you should see approximately 0.02 to 0.03 volts. This is the PCM idle voltage. It equals the difference between the CCD Data Bus (+) circuit and the (-) circuit. The (+) circuit should be around 2.49 volts and the (-) circuit should be around 2.51 volts. If you don't see the 0.02 volts the PCM driver for the ASD control coil circuit may be dead. You can verify the idle voltage at the Fuel Pump relay in the same manner if you like. Avoid jumping the ASD relay power contacts (Cavities 30 to 87) unless you are using a switch in the jumper that you can turn off while connecting the jumper, then turn on when needed, then turn off when disconnecting. The PCM frowns on ASD jumping. Cavity 30 is hot off the battery.



DTC P1694 with CEL is No CCD Messages received from PCM - Bus communication failure to PCM. P1694 without CEL is Fault in companion Module (TCM) but I think you've figured that out.

You may want to check your CCD Data Bus. Refer to the data link/CCD Data Bus image below.

You'll be looking for 2.49 volts on the (+) circuit and 2.51 volts on the (-) circuit. These voltage reading will vary but note that if the CCD Data Bus voltage is above 2.8 volts or below 1.8 volts communication on the Bus stops or is invalid.

Access the Data Link Connector. Use a digital voltmeter. Use a stong flashlight to see the pin cavities. Refer to the Data Link Connector pinout in the image. Ignition switch to RUN (engine off).

Measure the voltage between pin cavity 3 and cavity 4 and/or 5, you should see 2.49 volts.

Measure between pin cavity 11 and 4 and/or 5, you should see 2.51 volts.

If you get high or low readings on any of the Bus cavities, the CCD Data Bus is corrupted. Disconnect the TCM and see if the readings change. As you can see on the image of the Bus there are lots of modules that can affect the Bus. From what I can gather, the Instrument Cluster is the bias module (it creates 5 VDC on the bus) and the PCM is the termination modules (it converts the bias voltage to the 2.49 and 2.51 voltages.

You can check the termnation resistors by disconnectingthe battery negative cable, and using an Ohmeter, measure the resistance between pin cavities 3 and 11. The resistance should be close to 120 Ohms. If not, the wiring to the PCM or the PCM is bad.

Check these things out and get back.

CCKen

I thought I'd ask: Why did you have to jumper your battery? Was it Dead? Why was it dead? How old is your battery? - Batteries are only good for around three to five years. Have you had the battery capacity checked at a shop or store?

Have you cleaned all the ground points in your engine bay?

WADVR

Thanks for the detailed reply. I have a couple of those things to check but, I have already done a couple of them.

Yes I replaced the PCM with no change to the symptoms.

To clarify I jumped 85 on the relay to ground to activate the relay and connect 30-87 as designed. I have not checked the voltage between 85 and ground(negative battery post) but will do so in the morning.

I have checked the DLC voltage at pins 3 and 11 to be 2.41v across to pins 4,5 and also to the chassis ground. This voltage was the same with or w/o the engine running. I will measure the resistance and post my findings.

I have cleaned and inspected the PCM grounds at the coil and they are solid as well as the ones by the PCM. The battery terminals are clean and voltage drop between the posts and PDC, starter, chassis etc are well within spec. The voltage is 12.8 with the engine off and has a drop to 11.8 when cranking. Seems a little weak but not beyond the specs I have been told are acceptable. I have also jump started it to see if that would change anything with a 14 volt feed, but it did not help.my battery is an Optima red top that is about 3 years old. It was pretty solid prior to this accident.

The battery was dead from the dome light being left on for a week or two.

CCKen

2.41 volts at pins 3 and 11 is a bit low but that's not the problem; pin cavity 3 should be 2.49 +/- and pin socket 11 should be higher at around 2.51 volts. There should be a difference in the +/- circuits of around 0.02 volts (as created by the termination resistors in the PCM). Both reading the same may mean the CCD Bus wiring to the PCM is bad or the PCM is bad. Checking for 120 Ohms between 3 and 11 will tell the story. And, checking the voltage at the ASD relay socket pin cavity 85 will also check the +/- idle voltage difference.

With the engine running, the voltage readings should be cycling around showing that the modules are trying to take their turn communicating with the PCM.

You may want to disconnect the TCM and try 3 and 11 again and see if it makes a difference. That P1694 code is telling you something.

Normal procedure for problems on the CCD Data Bus is to disconnect modules (shown on the schematic) to see if the problem goes away. Disconnecting the instrument cluster would probably kill the CCD Data Bus.

Do you have a Security Key Immobilizer system? Do you have an overhead console? If so, these woud be next in line to disconnect after the TCM.