no start only signal from PCM on one cylinder

Hello,

It sounds like it could be the ASD relay. Here is some wiring diagrams and a guide so you can see how to test the wiring.

https://www.2carpros.com/articles/how-to-check-wiring

Please run some tests and get back to us so we can continue helping you.

Cheers, Ken

The crankshaft sensor is brand new, The camshaft sensor is brand new. Both sensors were tested for power (both were good), both were tested for grounds (both were good), both were tested for signal but cam back with no pulse/signal noted! All wires were tested for continuity and came back good.

The Coil Over Plugs - all 6 - coils were good for power, yet all 6 coils like that of the crankshaft sensor and camshaft sensor all came back with no signal/pulse noted. All the wires came back good for continuity.

The Fuel Injectors - all 6 - were good for power, yet all 6 fuel injectors like that of the crankshaft sensor and camshaft sensor all came back with no signal/pulse noted. All the wires came back good for continuity.

When trying to crank the car you can feel the ASD relay clicking and both fuse 24 and 25 in the Power Distribution Center show good and operating when cranked.

Likewise, I did change out the ASD relay with another relay in the Power Distribution Center just to make sure..... It made no difference!


The fuel pump can be heard engaging and one can even smell fuel being delivered up to the engine.


The following codes were able to be retrieved: P0123, P0320, P0340, P0353, P0645, P1282, P1388, and P1495.

Any ideas?

Gees, bunch of codes, Try to clear the codes and then try to start the engine and see what comes back, its sounding like you might have a bad computer.

Please let us know what you find ;)

Cheers, Ken

The only code after clearing the previous codes was code p1684 because of the battery having been disconnected to reset/clear the previous codes.

The rpm needle moves when cranking the engine.

How many cycles or engine being cranked does it take before new code(s) will be generated?

Only one code now..... P1684

That just means you have interrupted the power to the PCM. Here is an engine wiring diagram (BELOW) so you can check for power and computer reference volts among the sensors.

Here is a guide to ehlp you do some testing

https://www.2carpros.com/articles/how-to-check-wiring


Please run some tests and get back to us so we can continue helping you.

Cheers, Ken

The Cam Sensor, Crank Sensor, all 6 fuel injectors, all 6 coils, test good for power, and good for grounds on crank and cam sensors. Likewise, continuity check on all the wires for everything is good. Since resetting the PCM through disconnection of battery the car has been cranked a good 30 times with only the battery code showing up now. Prior to that, as stated, there was numerous codes. Still crank - no start. As stated the rpm needle does move to about 300-500 rpm when cranking.

As I stated before everything tests good accept for there is no signal pulse noted for the sensors, the injectors, or the coils.

We are missing something or the ECM is bad. Try disconnecting every non crucial sensor such as oxygen and mass tps to see if the injector pulse comes back.

Do you mean the PCM?

Which sensors are considered non crucial?

Give me a list and i'll disconnect them.

All O2's, TPS, MAF and coolant temperature.

Please let us know what you find, I am curious ;)

Cheers, Ken

The pcm reported code 118 and 123 as expected but still crank, no star, no signal pulse for the crank, cam, injectors, or coils

Forgot to mention the code p1684 code did not show when the codes p0118 and p0123 were found when at first cranking the engine without the non crucial sensors connected. However, now the p1684 code is back despite the pcm not being reset.

As the PCM and ECM are two separate boxes is there a way to test the ECM? How does the ECM work with the PCM?

Am I incorrect? Is the ECM and PCM one unit and the other box the TCM? How does one test the TCM?

What I thought was a separate ECM is actually the TCM. The PCM and the ECM are one unit on this car.

This sounds like a computer has gone bad in this car. Try to find a used one to plug in and try. Did you ever check the wiring from the diagrams I gave you?

This is the second PCM with the same issue noted with the original, the first replacement, and now this one. Yes, I used the diagrams. The grounds on the crank and cam sensors are grounded through the PCM. When cranking both the ASD and TCM relays are shown as good. Likewise, as they are operating accordingly and the rpm is seen as jumping to the 300-500 mark in the instrument cluster panel is an indicator that the PCM ground is good. Thus, is it possible that the TCM somehow is interfering with the PCM.... I.e. not providing signal to the PCM?

Is there a way to test the TCM?