My car overheated and now im getting 21,34 for error codes...

[91SkylineGts-t]

OK i was driving my car home last night and the car over heated and shut off. apprently my temp gauge isnt working. i had my car towed home and left it over night. i found out this morning that the coolant line on my turbo had rotted and split open. i checked my coolant level and it was low. i replaced the coolant line refilled all coolant back up and tried to start it. now the engine turns over and dosent even sound like its trying to fire up. i checked my ecu for error codes and im getting codes 21 and 34. i looked up the codes and they are

21 Ignition circuit
34 Knock sensor

... What happened and how do I fix it?

[Skym]

Excessive heat in engine bay can affect the ignition module on top of back of engine. Excessive heat might have affected knock sensor as well, that's connected to shortblock. Replace both.

[91SkylineGts-t]

this happened to an r33 gtst. I have an r32 gtst parts car in my back yard are the ignition modules the same???

[judasentinel]

Ignition modules are not the same. The R33 modules are POS in my opinion. The ones on an RB20 are much better, as the wiring on the R33 one is different and there are more wires on it. But you cannot use the one from an RB20, unless you rewire it properly. If you want to use the stock harness, then you have to look for an RB25 (R33) ignitor.

Looks like you melted the ignitor or at least burned some wire or circuitry inside it. You may need to do a continuity test with a multimeter to find out where the fault lies. Any fault AFTER the ingition module up to the coils will not give you an error code. Code 21 flashes only when the ECU is unable to get a proper signal/connection with the ignitor.

Remember that all fault codes on our ECUs are sensor-related. They do not identify physical component damage, but an electrical fault, which could or could not be due to a faulty sensor or a damaged physical part.

As regards the knock sensor code, I would check both the sensors (I think there are two on the RB25DET), to see if the wires are melted or something due to overheating.

I can assure you that if you somehow get a replacement ignitor and install it, your car will fire up. But if there has been any catastrophic damage to the engine internals themselves due to overheating, it wont fire up even after replacing the ignitor. So start with the ignitor and then move to the knock sensors.

Keep us posted on what you find.

[91SkylineGts-t]

will do

[91SkylineGts-t]

Hmm skym and juda i switched my ignition module out with my buddies from his r33 and it was a no go. nothing happened except the starter spining. no spuddering or nothing. Im really stumped now. what should be my next step??

the ignition module is the electrical pice ontop of the coil coers near the firewall right??? with the 2 harness clips? cause thats what i switched out

[91SkylineGts-t]

bump i still need help

[judasentinel]

This is what you need to try out now:

1. Check your ECU for codes. Chances are that you may still be getting Code 21, which means that the error is not in the ignition module. To confirm this, take YOUR ignition module and put it on his friend's car. See if his car fires up. You need to do this in order to be sure wether your ignition module is F U C K E D or not. From what I am sensing, your ignition module should be ok.

2. If your car's friend fires right up with your ignition module, you will still be getting an error code 21 on your car. Now is the time to start looking for wiring damage due to overheating. Look for any wire melting or broken connections. You can also do a continuity test for all the 6-7 wires running from the ECU to the ignition module.

3. Check the connection of the ECU to the knock sensors. If due to overheating your sensor is fried, then you have to replace the sensor. I doubt your engine is dead, but then you never know.

4. Do a compression test and leakdown test on each cylinder to see if you damaged your internals.

5. Check the coils for spark one at a time when you turn the engine. If you are getting a spark in each coil with an ignition module, then you can rule out ignition problems.

6. Take your CAS out, hold it in your hand. Turn the key to ON position. Now slowly rotate the rod at the back of the CAS. You should hear a TICK 2-3 times with every single complete rotation of the CAS. This ticking sound is the opening up of the injectors. You need to make sure that your injectors are firing up, because if they dont, your car wont start up.

7. Check your intake and turbo piping for any leaks and/or open/loose hoses. If the air is leaking in or out, you may have a hard time starting the car.

8. Check the MAF plug as well

The above should get you going for a bit and you may find a problem.

[91SkylineGts-t]

hey juda could you pm me your number???

[91SkylineGts-t]

i was super busy last night so im gonna start going through all the electrical today.

[aman1515]

dose anyone know if s2 ecu will work on s1 rb25det?

[91SkylineGts-t]

I was talking with juda and im 99% sure he said there diffrent.

[Skym]

Series 2 R33 ECU has a coilpack shut off feature. Series 1 R33 ECU doesn't.

On Series 2 R33 engine the ignitors for coilpacks are built into coilpacks (for the coilpack shut off feature on ECU) and ignition module on back of engine is smaller due to this change.

On Series 1 R33 it's the same as R32 GTS-T, have to remove coilpack cover, unplug the coilpacks one at a time to check for faulty coilpack. Faulty coilpack usually doesn't affect engine.

Series 1 R33 is like R32 GTS-T. But Series 1 R33 has VVT on engine (and features on ECU to control it), onboard boost control on ECU.

[supersayianjim]

any updates on this??