[garson]

hi all
recently purchased this neon lx 2l problem is i cannot get it to even crank was able to bypass relay it did crank what i disd see it is as if there is no power to pcm because cannot even get any dtc. checked all fuses and relays have verified good grounding, please help

 

[ImperialCrown]

Welcome to Allpar. This PCM wiring diagram should be similar.
The Rd/Wt wire at the PCM should have battery 12v power.
The Dk.Bu/Wt should have ignition on 12v power.
There are distributed (Bk/Wt and Bk/Tn) grounds to body ground.
In the top, left corner more PCM pin outs are shown including your starter relay with the Bn/Yl ground return wire.
This isn't a Chrysler wiring diagram and no year is stated, but I hope it is accurate.
If a 5 volt or 8 volt sensor supply voltage (Bk/Lt.Bu or Or) is shorted to ground, the PCM will go into 'protection' with no 'ck eng' light or scan tool communication. This short can be at the wiring harness (cuts and rub-throughs against a sharp corner were fairly common) or the sensor short-to-ground itself. You can unplug one sensor at a time followed by a key cycle (reset) until the PCM resumes operation. Or possibly the PCM itself is failed.

Engine_Electrical.jpg

 

[Bob Lincoln]

Check fuses, both underhood and in the interior.

 

[garson]

Hi
thanks for the reply ihave checked all fuses and relays
will check the pcm out



hi me again just want to know if there is a way of testing the pcm.
thanks

 

[ImperialCrown]

The only testing that can be done is by making sure that everything external to the PCM is in order first (voltages, inputs, outputs, etc.) then start looking into what the PCM itself is seeing or not seeing. This could be displayed on a good scan tool under a sensor/input/output menu display. A good diagnostic tool would be the factory DRB III (or equivalent).
Faulting the PCM itself is the last house on the block in any diagnosis, except maybe fault code P0601 (internal ram failure), but I usually like to erase that fault once to see if it comes back.
There may be no fault code for not cranking. Make sure that the PCM sees a Park or Neutral switch input and can ground the starter relay when asked. Does the car have an aftermarket alarm or remote start system?

 

[garson]

Hi
no it has the original system .will do some testing today will keep you informed

Thanks

 

[garson]

hi
checked all wires going to pcm i am getting 12v where applicable
what i have noticed is the clutch interlock is missing and the red, black and yellow wires are terminated together not sure if that will bypass the interlock or not( manual gearbox)

 

[ImperialCrown]

Sorry, didn't realize this was a stick-shift. The clutch switch may be a 2-stage switch and it may be required. Jumping it may not solve the no-crank.