First thing is to see if the crank position sensor is sending a signal. without that signal there is no spark and no fuel injector operation.

With so many diverse codes, there maybe a wiring issue. PCM replacement is only after everything else is ruled out.

 

Thanks for the advice. I will research on how to check this sensor.

 

. . . . have the following codes, P1192, P1496, P0107, P0117
I can clear the codes with my scanner and as soon as I just turn the key on they all return immediately. . . . .

You did not indicate the specific engine in your vehicle. Is it a 2.4 liter 4 cylinder naturally aspirated or 2.4 liter turbo engine? It makes a difference when reviewing engine wiring diagrams.

First thing to try is to open the air intake near the throttle body. Inject a 5 second squirt of starting fluid into the throttle body with the throttle butterfly valve open. Engage the starter. If the engine starts, runs a few seconds and then dies you know timing is correct and valves functioning and spark is present. The issue is fuel delivery from the tank through the fuel injectors. If the engine does not start and run a few seconds then it is incorrect valve timing or lack of spark or other.

These are code interpretations.

P1192 CHRYSLER - Inlet Air Temperature Sensor Circuit Low Condition

Possible causes
· Faulty Inlet Air Temperature Sensor

· Inlet Air Temperature Sensor harness is open or shorted

· Inlet Air Temperature Sensor circuit poor electrical connection


P1496 CHRYSLER - 5 Volt Supply Voltage Low Condition
Possible causes
· Shorted sensor

· Sensor harness is open or shorted

· Sensor circuit poor electrical connection

· Faulty Powertrain Control Module (PCM)



P0107 CHRYSLER - Manifold Absolute Pressure Sensor Circuit Low


Possible causes

Faulty Manifold Absolute Pressure sensor Manifold Absolute Pressure harness is open or shorted Manifold Absolute Pressure sensor circuit poor electrical connection Faulty Engine Control Module (ECM)



P0117 CHRYSLER - Engine Coolant Temperature Sensor Circuit Low

Possible causes
· Low engine coolant level

· Faulty Engine Coolant Temperature (ECT) sensor

· Faulty engine coolant thermostat

· Engine Coolant Temperature (ECT) sensor harness is open or shorted

· Engine Coolant Temperature (ECT) sensor circuit poor electrical connection

 

2002 turbo was not available, yet. My daughter's 2002 just died yesterday, the belt tensioner broke from the sounds of it.

With yours, definitely a wiring issue to be the first thing to look at. There is a wire connector behind the radiator, you get to it from underneath, that may be a good place to look for damage of some sort. You can check to see if the timing belt is still functioning properly by looking into the hole in the timing belt cover, have someone turn the engine over and look through the hole, make sure the camshaft sprockets are turning. Turn the engine over a couple seconds to make sure the belt isn't just chattering a little bit.

 

Thanks AlanC for that info.

I installed a new timing belt when I replaced the head gasket and tested the smooth operation of the cams and belt before covering it all back up and all was good.
I just went out and cranked the engine once again watching the tach and there was no indication of any rpm on the tach while cranking.

Next will be get it jacked back up and start checking the wiring underneath at the crank sensor and behind the radiator.

 

I see a lot of codes that could be because of a missing or low 5 volt sensor power supply. Do you have 5 volts out of the PCM?
If the 5 volt line is shorted to ground somewhere, the PCM will shut down the supply for protection. Once the short is removed and the key cycled (off-on), then the 5 volts should come back. Shorts can be intermittent.
The 2001 PT powertrain diagnostic manual should be the same for 2002. Look up the Possible Causes for each code to see what cause(s) they may have in common.
Connector pinouts, wire colors and simple wiring diagrams are at the back of the manual:
http://oskin.ru/pub/chrysler-dodge/manuals/Service Manuals/2001_PT_PTCruiser/01PTEP.PDF
Was it running before the head gasket and timing belt work?

 

I also tried the starter fluid test and there was no fire.

 

No, it was not running before the head gasket replacement.

 

Thanks for the link to the manual. I will see what I can figure out.

 

I seem to remember that the ign coil pack and the MAP sensor used the same style black plastic 3-pin connector and could reach either component.
It was easy to swap them mistakenly after engine work was performed and of course the vehicle wouldn't start afterwards. Check your wire colors.

 

The coil pack and MAP sensors are properly plugged in according to the wire colors.
If I clear the codes only p0107, p0122 and p0117 only come back with just the key on.
I have 5v at the supply line going to the map sensor. When I crank the engine the others come back.

The p0117 code gets me as the sensor is new and the thermostat is new and the wires look good and are still flexible.

The absence of a signal to the tachometer when cranking the engine is confusing me.

 

. . . . If I clear the codes only p0107, p0122 and p0117 only come back with just the key on.
I have 5v at the supply line going to the map sensor. When I crank the engine the others come back. . . . .

You did not report code P0122 previously? Is this a new code that has appeared since you started your diagnosis? Have you checked all fuses in the PDC (power distribution center) for continuity and none have failed?

Code P0122 indicates low voltage at the throttle position sensor and is a common theme among all the diagnostic codes. So I am thinking that there is a short to ground in the power source wires to various sensors, the PCM is sensing this and disabling circuits to prevent internal circuitry damage.

Why did you replace the TPS (throttle position sensor)? Look at the attached images that show various sensor circuits. I would unplug the throttle position sensor and see if the engine will start.

Do you have 8 volts at PCM connector C2 pin #44 when starter is engaged? That pin provides power to the crankshaft position sensor and camshaft position sensor.

Do you have 5 volts at PCM connector C2 pin #61 when starter is engaged? Do you hear the fuel pump power up for 1 - 2 seconds and then stop running when turning the ignition key switch from OFF to RUN?

 

I looked back through photos I took of the codes before I started the head gasket repair and yes P0122 was there and that is why I changed the TPS sensor. The fuel pump does operate when the key is turned to run and then shuts down as it should.

What's the best way to get to the outputs to check the voltages you listed? Do I need to unwrap the harness and then pin the wires or is there a better way? I'm comfortable with mechanical but I've never had to deal with digging into the wiring end of it much.

 

. . . . The fuel pump does operate when the key is turned to run and then shuts down as it should. . . . .

The fact that the PCM can control the fuel pump is encouraging. That means the ASD relay and fuel pump relay are functioning. Try this test. Area around the vehicle as quiet as possible. Engage the starter for 5 seconds and then release ignition key to RUN position. Do NOT turn of OFF. Do you hear the fuel pump continue to run for 1 - 2 seconds and then stop?
If YES then the PCM is receiving a proper signal from the crankshaft position sensor that the crankshaft is rotating and the PCM energizes the ASD relay which provides power to the fuel injectors and ignition coil.

If NO then there is a problem with the crankshaft position sensor and / or the wiring to the crankshaft position sensor.

. . . .What's the best way to get to the outputs to check the voltages you listed? Do I need to unwrap the harness and then pin the wires or is there a better way?. . . ..

The best way is check terminals at electrical connectors is to use different size T pins that are designed for such testing. You can probably substitute various diameter paper clips. You insert the straighten paper clip on the back side of the terminal you want to test. You have to make sure you do not not damage the individual electrical receptacle and have good contact. Make sure the improvised T pin does not contact an adjacent pin or a ground on the engine. Use a volt - ohm meter to check voltage on the T pin.

Here is a link to a video that shows how to back probe electrical connectors.

View: https://www.youtube.com/watch?v=g2ST8w_0w-Q

 

Thanks AllanC. I'll have to see what the weather is like tomorrow. Everything is done outside, no garage available.

 

The wiring harness that runs under the early PT's was held up by cheap plastic keepers. These were known to break and allow the harness to drop down and rub against the passenger side axle. I'd look at that and see if maybe that's what happened. Even if it's not dragging now, it could have been improperly repaired by someone in the past and the repair has failed. At least you don't have to worry about a faulty TIPM. Those came into the PT's in 06 and are not cheap to replace. Check all of your ground connections on the driver side fender too. You'll need to remove the air box in order to see them. Should be 7 different grounds attached at 2 places there.

 

Latest update.

I installed a new crankshaft sensor and the computer is reading it. I tried cranking the engine and when I stop I can now hear the fuel pump running for a second after the cranking stops.

I pulled both connectors from the computer and started checking the sensor connectors for shorts. The MAP sensor connector is showing a short between the 5V supply and ground.

When it's not raining I will see if I can find where the short is located.

Thanks for all the help so far.

 

. . . I installed a new crankshaft sensor and the computer is reading it. I tried cranking the engine and when I stop I can now hear the fuel pump running for a second after the cranking stops.

I pulled both connectors from the computer and started checking the sensor connectors for shorts. The MAP sensor connector is showing a short between the 5V supply and ground. . . . .

Great follow up and getting some positive results to narrow the focus on the problem area.

Attached image shows the location of splice S108 that provides the 5 volt power to the MAP sensor and TPS. This may be of some help.

 

Well, it quit raining today so I started digging into the wiring harness. I separated a number of wires that were stuck together but didn't appear to be melted.

When I started this today I had the dead short on the map sensor until I unplugged the TPS and it went away. After inspecting wires now the dead short wont return but I am showing 5 ohms which disappears when I unplug the TPS. I checked the 5V to ground on the new and the old TPS and they both measure 5 ohms.

Should I be reading this resistance across the TPS?

 

. . . When I started this today I had the dead short on the map sensor until I unplugged the TPS and it went away. After inspecting wires now the dead short wont return but I am showing 5 ohms which disappears when I unplug the TPS. I checked the 5V to ground on the new and the old TPS and they both measure 5 ohms. . . . .

See attached image. From your description it appears there is a short between the signal wire terminal and the sensor ground terminal; #2 and #3 in the diagram.

. . . Should I be reading this resistance across the TPS? . . .

See notes on attached image.

 

Between 1-3 I have a constant .48 ohms
Between 1-2 I have a decrease from 4.88K - 360 ohms
Between 2-3 I have an increase from 62 ohms - 4.6K

No zero's anywhere.

 

0.48Ω would effectively be 0Ω.
The signal terminal should be from the wiper of the potentiometer as it varies with throttle opening. The 5 volts to ground potential is distributed across the TPS resistance shoe.

 

sorry the first should have read 5 ohms

 

Just discovered that my injectors are now firing but I'm still looking for spark.

 

Map sensor looks good. I measured resistance in all pin combinatons.

I was checking the ignition coil circuity and the asd relay is not being activated by the ECM to provide 12V to energize the coil. I ran the wiring to the ECM plug and it is good. I have continuity all the way to the ECM connector. With what I a have read I should have 12V to the coil with the key turned on. Is this correct?

 

. . . . Map sensor looks good. I measured resistance in all pin combinatons. . . . .

OK. You can rule out the MAP sensor as the source of the problem.

. . . .I was checking the ignition coil circuity and the asd relay is not being activated by the ECM to provide 12V to energize the coil. I ran the wiring to the ECM plug and it is good. I have continuity all the way to the ECM connector. With what I a have read I should have 12V to the coil with the key turned on. Is this correct? . . . .

The PCM only energizes the ASD and fuel pump relay if it receives a valid signal from the crankshaft position sensor that the crankshaft is rotating. So with key ON / RUN position but starter not engaged there will be no electrical power flow through the load side of the relay. This is a safety feature built into the PCM logic.

Try this test. Swap the ASD relay with the starter relay in the PDC. Engage the starter. See attached image. It is possible that there was a short in the wiring harness that you previously found and have inadvertently corrected. It is possible that the load side contacts are burned / pitted in the ASD relay and are now not providing adequate current flow to the fuel injectors and coil.

 

I plugged everything back in and swapped the relays.

I also checked the coil while cranking and the ASD was supplying the voltage as you stated it would.

I back probed the 5V supply to the MAP sensor and it was a steady 5V while cranking.

I'm still getting P0122, P0117, P0107 and P1192

The codes were clear when I started today as the battery was disconnected.

Thanks for the help as I really appreciate it.!

 

. . . I plugged everything back in and swapped the relays.

I also checked the coil while cranking and the ASD was supplying the voltage as you stated it would.

I back probed the 5V supply to the MAP sensor and it was a steady 5V while cranking. . . . .

OK. ASD relay is good and will pass adequate electrical current to fuel injectors and coil.

You need to check for 12 V power at fuel injector harness and at the coil. See attached image. CAUTION: use a test light with an LED bulb. Test lights with an incandescent bulb can draw 1 - 3 amps and this can damage control circuits in the PCM.

Check for 12 V power while engaging starter. Then check the PCM control circuits to the fuel injectors and coil. If you do not see a pulsing lamp when checking the control circuits then the PCM has failed and will need to be replaced.

Here is a video that shows how to use a test light to check pulsing at the fuel injector. Vehicle is a Honda but the principle shown is for many vehicles.

View: https://www.youtube.com/watch?v=pzeOz-seIQE


At time interval 5:40 the presenter shows how to check for proper voltage at the fuel injector harness. On the Honda the ignition key is in the ON / RUN position. On a Chrysler vehicle you will need to engage the starter so the crankshaft is rotating and the ASD relay closes to provide power to the injector and coil.

At time interval 6:22 the presenter shows how to check for proper ground at the fuel injector harness. Again engage the starter and you should see pulsing on the test lamp. That means the PCM can control and ground the fuel injector electrical circuit. No pulsing means the PCM has failed.

Do a similar test on the 2 control wires between the coil and PCM. Test lamp should show pulsing on coil control wires.

 

Thank you. I will get a test light tomorrow. Looks like Harbor Freight sells them.

Just an FYI, if the computer is damaged there is a company in Illinois that tests and repairs them and sends them back for $115 and they supposedly give a lifetime warranty on the repair. I found them on Ebay and used them to fix a Durango ECM a while back.

 

You are on the right track. Let's hope the PCM is not damaged but it is nice to know of a reliable and reasonably priced service if replacement is necessary.

 

Thanks again AllanC. Drove to the nearest Harbor Freight and got their computer safe LED test light and tested both the ignition and injector harness. Both had 12v but there was no life in the control circuits on either. I just unplugged one injector and the plug for the coil and tested them that way. Is that acceptable or do I have to leave them plugged in and back probe them?