No power to coils and injectors?

Hi,

For the injectors to spray, they must be getting power and a ground path from the PCM.

When you turn the key to the run or start position, power should be present at each injector. To complete the circuit and actuate an injector, the powertrain control module (PCM) provides a brief ground path. If they are spraying all the time, power is present and it sounds like the PCM has failed and providing that ground at all times.

If you look at the pic below, it shows the injectors. Note that each injector has a brown wire with a white tracer. Once the key is on, there should be 12v present at each injector via those wires.

Let me know if that is what you have.

Take care,

joe

See pic below.

So, they do have power at the brown/white wire for about 2 seconds when I turn the key on. Injectors 2, 3, and 4 spray as soon as you turn the key to on then shut off after 2 seconds. I found a couple of possible shorts which I fixed. Injector 3 stopped spraying now it's just 2 and 4. Also someone replaced the transmission and now it won't start because of the open injectors.

Hi,

Where was the short? Also, power shouldn't stop at the injectors. It is supplied by the automatic shutdown relay (ASD). It is located in the under-hood fuse box.

Here is a thought. If this just started since the transmission was replaced, inspect the connectors at the totally integrated power module (TIPM) which is basically the under hood fuse box. They may have had things unplugged and damaged pins when they reconnected things. The connector pins at the TIPM are many and very small. The ASD relay and fuel pump relay are both located there. However, the fuel pump relay is integral to a printed circuit board and not serviceable.

Let me know.

Joe

There are 2 ASD fuses and an ASD relay. Both of the fuses get 12 volts for about 2 seconds also and then shut off. I switched out the relay to see if that was the problem, but it wasn't. Is it supposed to shut off like that?

Are you able to tell me where and how many main grounds there are on the body in the engine bay? I just want to make sure all of them are there and in the right spot.

Also, the lightning bolt light is on the dash. I looked it up and it said it could be the electronic throttle control system? The wires before the connector to the throttle body are connected with wire connectors like someone put a new connector on it. Should I take them off and solder the wires together, would that help? Sorry about all the questions.

Hi,

I have a feeling I know what is happening. This vehicle has a totally integrated power module (TIPM). They have connectors that have (as far as I'm concerned) too many pins. As a result, the pins are small and prone to damage, corrosion, and breakage. I suspect that is where the short is.

The idea that you get power for a couple seconds and then lose it to the ASD is likely being caused by a poor connection that can't handle a load.

So, the TIPM is basically the power distribution box under the hood. Under the fuses are the modules. We need to check the connectors for damage or corrosion.

Before you start, disconnect the negative battery terminal. There are several different connectors. I attached several pics below. Primarily, we are looking for the connectors related to the ASD. I highlighted the connector numbers, the pin locations in the connectors, and a legend showing the purpose of the pin.

I suspect the TIPM is going to need to be replaced. A power supply that drops off is a common symptom with these when they fail. But the best thing to do is confirm there is an issue. It isn't a cheap part.

Let me know what you find.

Take care,

Joe

See pics below.

Would that cause 2 of the injectors to spray as soon as the key is in the on position then shuts off when the ASD shuts off?

If there is a short to ground via the PCM, that could cause it as well. However, the PCM doesn't explain why you lose power to the ASD.

If possible, check the affected fuel injector wiring to see if there is constant continuity to ground when the key is on. Make sure the connector is disconnected to prevent the injector from actuating while the ASD powers on. If you have constant ground, then we need to check for a short in the wiring to ground or at the PCM connector. Also, the PCM may be shorted internally, so this technique will get us moving in the right direction.

Let me know.

Joe

Okay, I will do that. Is there a diagram for the PCM connector to find the grounds? Thank you

And also, a diagram for the CKS connector someone replaced the connector and I just want to make sure the wires are connected correctly. Thank you again.

Hi,

Absolutely! If you look below, the first two pics are for the crankshaft position sensor. The remaining pics are for the powertrain control module. (PCM)

There are 4 connectors at the PCM. Following the pics in order, I first attached the connector identification, the connector pinout, and then what each pin is for. Following them in order you will go each connector one at a time.

Let me know if this helps.

Take care,

Joe

See pics below.

So, I did I continuity test on all the injector wires and connectors and all of them are good but when I do it on the PCM pin out I get a reading on the multimeter, but it doesn't beep? Do you think it's the PCM then?

Hi,

If the PCM isn't providing a ground path when the engine is cranking, yes, it is likely the problem. However, if you are checking it without cranking the engine, there will not be a ground path.

Keep in mind that the connector at the PCM may be a problem, so make sure you check that as well.

Let me know what you find.

Take care,

Joe

I checked the continuity on the injector pinouts on the PCM and 3 of the 6 have continuity without cranking.

If you have a constant ground path at the PCM, it has an internal short. Just make sure the connector isn't the issue. If it isn't, replace the PCM.

If you look below, I provided the directions for the removal and replacement of the PCM.

Also, the new PCM will need to be programmed.

Let me know if this helps or if you have other questions.

Take care,

Joe

So, I got a new computer and that fixed the injector problem. The car starts now but the idle surges and jumps up and down. The lightning bolt light is on the dash and the throttle body starts clicking when I turn the key on. Could the throttle body be bad?

Hi,

We need to scan the computer (can-bus) to retrieve codes. The lightning bolt indicates an issue with the throttle control circuit. Could it be the throttle body? Anything is possible. However, it could be a throttle position sensor, wiring, accelerator position sensor, and so on.

When I say scan the can-bus, that refers to the Controller Area Network. Basically, the different modules are tied together via a few wires and communicate with each other. This type of scan will retrieve codes regardless of the module storing them. By doing this, it will help point us in the right direction. Otherwise, it will become a guessing game which can get expensive.

Here is a link that explains how it's done:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Let me know if that is something you can do or have done.

Take care,

Joe

Where is the throttle position sensor located? And I have an obd2 scanner, but I don’t think it has the can option on it. The check engine light is on, but no codes are popping up on the scanner. And also, I found that the charcoal evap canister is completely melted and the lines going to it were melted off I’m assuming from the exhaust. Whoever owned it before cutting off the mufflers. Would that canister cause any issues? And thank you for responding.

Hi,

The canister will cause evaporative emission system problems. Also, I suspect the vacuum hoses to it were melted as well, so that would have caused drivability issues as well.

The idea that the check engine light is on with no codes indicates either your scanner can't read the code type or there is a breakdown in communications between the modules and data link connector.

When the exhaust was modified, where was it cut? Are the catalytic converters still on the vehicle?

Let me know.

Joe

Yes, the vacuum hoses to it were melted also. The cats are still on they cut the mufflers off.

This is what the canister looks like.

Now that the canister is discontinued it's not revving so high and I have a code of p0204 injector circuit open cylinder 4.

Hi,

Wow, that is a mess. The part that is badly melted is the Evaporative System Integrity Monitor (ESIM). The ESIM mounts directly to the canister. It allows air to vent during refueling. During refueling, pressure is built up in the evaporative system. When the pressure reaches approximately 5 inches of water, the large check valve unseats and pressure vents to the fresh air filter.

This isn't causing the electrical issues, but it does add some insight into the vehicle's prior use. The exhaust being modified does as well.

Check closely for melted or damaged wiring. I have a feeling that is what is going to be causing the issues.

Joe

I have good news. I found that the egg valve pipe going from the intake was leaking and causing a vacuum leak. It runs now but have a code P0344 camshaft circuit intermittent. Do you have a diagram of the camshaft position sensor plug with the wire colors? Thank you for all the help.

Hi,

That's good news. As far as the sensor wiring, I attached it below for you. Let me know if that is what you need. Also, just out of curiosity, do you mean EGR valve? I'm not familiar with an EGG valve. I suspect that was a typo, but anymore, I never know. LOL

Let me know.

Take care,

Joe

See pics below.

Lol yes the EGR valve. Thank you