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4x4jeep

4x4jeep 6/23/2020

2002 Jeep Grand Cherokee Laredo 6 Cyl 4.00L

Engine

Cannot I fix code p0204

This is a 2002 4x4 Laredo 6 cylinder 4.0.. this site will NOT let me choose that engine
I cannot get rid of this code I replaced the PCM with one I got from eBay , spark plugs, coil, the injectors ... I removed the wiring harness and checked it. I have put a new fuel pump into this thing
if I unplug number 4 injector wire it flashes a noid light but t will not fire an injector I hold in my hand... if I plug an injector into one of the other plugs I can feel the pulse in my hand , number 4 injector wire puts out approximately 11 volts if I switch number 3 and 4 injector wires the code stays with cylinder number 4
I had to buy a PCM pigtail and solder it in because I messed up the original PCM plug I did one wire at a time and made sure everything was done correctly with solder and heat shrink tubing
I have no idea what is going on with this thing I cannot afford to bring it to a shop I just want to sell it and get rid of it if anyone knows how I can fix this please tell me..

2 Answers


Jimm

Jimm 6/24/2020

P0204 = Injector Circuit Malfunction - Cylinder 4

You will need electrical repair training and tools: volt-ohm meter, scan tool (for freeze frame data), noid light, wiring diagram / schematic, repair manual.
Plus the skills and training in wire harness and connector testing (pinout / wringing / continuity)

1) Learn the basic electrical theory, system and knowledge (ohms law for example).

2) Start with these components - harness, injector, connection, ECM

What causes the P0204 code?
Open or shorted wiring harness,
Failing cylinder 4 injector,
Poor electrical connection,
ECM is faulty.

Diagnose the issue in the order shown.

How does a mechanic diagnose the P0204 code?
Hooks up a scan tool into the diagnostic link connector (DLC) port on the car and pulls all codes that are stored in the system

Observes the freeze frame data associated with the codes (each one tells the technician when the code was triggered and what the vehicle was doing).

Clears all the codes and performs a test drive under similar conditions obtained from the freeze frame data

Performs a visual inspection if the P0204 code returns

Uses the scan tool to check for proper ECM readings coming from the injector circuit cylinder 3,

Checks the voltage with a multimeter at cylinder 3 fuel injector

If needed, installs a noid light between the fuel injector and its wiring (noid lights measure the voltage pulse width which tells technicians if the injector is opening for long enough)

Performs a test of the ECM if none of the other tests offer anything conclusive.

Read more: https://www.autocodes.com/p0204_jeep.html

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Jimm

Jimm 6/24/2020

P0204 = Injector Circuit Malfunction - Cylinder 4

You will need electrical repair training and tools: volt-ohm meter, scan tool (for freeze frame data), noid light, wiring diagram / schematic, repair manual.
Plus the skills and training in wire harness and connector testing (pinout / wringing / continuity)

1) Learn the basic electrical theory, system and knowledge (ohms law for example).

2) Start with these components - harness, injector, connection, ECM

What causes the P0204 code?
Open or shorted wiring harness,
Failing cylinder 4 injector,
Poor electrical connection,
ECM is faulty.

Diagnose the issue in the order shown.

How does a mechanic diagnose the P0204 code?
Hooks up a scan tool into the diagnostic link connector (DLC) port on the car and pulls all codes that are stored in the system

Observes the freeze frame data associated with the codes (each one tells the technician when the code was triggered and what the vehicle was doing).

Clears all the codes and performs a test drive under similar conditions obtained from the freeze frame data

Performs a visual inspection if the P0204 code returns

Uses the scan tool to check for proper ECM readings coming from the injector circuit cylinder 3,

Checks the voltage with a multimeter at cylinder 3 fuel injector

If needed, installs a noid light between the fuel injector and its wiring (noid lights measure the voltage pulse width which tells technicians if the injector is opening for long enough)

Performs a test of the ECM if none of the other tests offer anything conclusive.

Read more: https://www.autocodes.com/p0204_jeep.html

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0

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