How to Cure 205 Code 54 Post FMIC Install

Cure 205 Code 54 Post FMIC Install

What are you going on about?

Code 54 - this is an error code the stock ECU generates to say that it isn't happy with the intercooling system. Click here for an article on how to check for 205 error codes.

FMIC - this is a replacement for the stock WTA intercooling system on the 205. This system is much more efficient as dispersing heat than the stock system, especially when the turbo is worked hard for a sustained period of time.

Note - properly fitting a FMIC to a 205 requires considerable effort, time and money to get the job done correctly...

Ok, big picture what has to be done?

The ECU is informed of an error by the water level sensor in the intercooler or from the intercooler water pump activation circuitry. A fault detected in either of these two areas causes the ECU to show a code 54 and the car slows down...

Therefore both these items need to be addressed:

Water level sensor - simply bridge the connections on the plug connecting to the intercooler

Pump - install 2 resistors as per the "How to..." below.

Note - I consider this to be the best method since you can remove the pump in it's entirety, unlike some other methods e.g. looping the output of the pump.

What are the benefits of this method over some others?

This method allows you to remove the intercooler system as a complete unit i.e. intercooler, pipe work and pump.

Also worth noting is that the electrical load placed on the car is less since the intercooler pump will not require powering...dependant upon voltage supplied this will save the alternator from producing ~3.5 Amps

Why all the fuss!?! It's easy on a 165 and 185!

The 205 is wired differently and the pump is not just simply connected to a relay and powered on and off like on the 165 and 185...


This picture here shows all the connections for the intercooler pumps available for GT4s. Note the number of pins for the 205 pump connection 165 - 2 185 CS - 2 205 - 5	Picture of the rear of the 205 connector	The wiring within the mini-loom for the pump is not straightforward. Note the resistance wire and several of the wires are joined together with the loom	However, as you would expect there is only 2 wires powering the pump

Ok, what is the circuit diagram so I can see what's going on a little better?

ORIGINAL WIRING

Note the resistance wire of 4.5Ω

MODIFIED WIRING

The modified circuit, clearly showing that the pump and resistance wire has been replaced with two 1kΩ resistors. Note that this is not in direct proportion to the original resistances, but these values work great and clear the code 54...

What tools do I need?

1 x spade end crimp - to bridge the intercooler level sensor
2 x 1kΩ resistors. You can get these from e.g. rswww.com or www.maplin.co.uk
Soldering iron
Heat shrink

How did you get rid of that pesky code 54 on a 205?

The job took ~2 hours including pump removal...

Note this is applicable to a 205 with a 205 wiring loom, NOT a 165/185 running a 205 ECU and loom
See below for the wiring for a 205 ECU in a 165 or 185

	The easiest part is to bridge the connector for the intercooler water level sensor. Unplug the intercooler and connect a spade end crimp into the loom
	Remove the pump from the car, and it looks something like this...
	Bare back some of the insulation material to reveal some of the wiring - note here the cover over the impellor has been removed, this is not necessary unless you want to see what is going on inside the pump
	Next, chop back the wiring so it looks like this - note I have already soldered the black yellow and white wires together
	Then solder on two 1kΩ resistors as shown - this was my prototype, note that you should insulate the bare soldered connections; sliding on a piece of heat shrink prior to soldering on the resistors is a good idea - don't use insulating tape!
	The finished prototype complete with heat shrink

What if I don't want to chop the plug off my pump?

Some chopping is going to happen somewhere! Either remove the engine bay loom plug for the pump or the plug from the end of the pump...unless someone has a better idea?

What if I have been clever and put a 205 engine with loom and ECU in my 165 or 185?

Do not follow the solution for 205 owners above,

165 & 185 ECU WIRING

Note the addition of a relay and two 1kΩ resistors

Any questions or comments then please feel free to e-mail me

Other jobs to do at the same time?

Not really

Disclaimer
This article is intended as a helpful guide and shows how I cured the error code 54 on a 205 fitted with a FMIC. If you are in any doubt, or not qualified, do not undertake this modification, consult a qualified mechanic. Always consult the manufacturer's manual. Alterations away from the manufacturer's specifications are not recommended.

Thanks to Scotthaniel for the circuit diagram for 185 owners