Category talk:S1
Misfire Detection Module (VVC)
In 2001 there was a factory recall to fit a misfire detection module to VVC engined S1 111S models.
The purpose of this module is to detect the presence of a misfire, and prevent overheating of the catalyst by turning off the injectors of the affected cylinders.
A problem occurs when this system detects what it thinks is a misfire, and turns it into a bigger misfire, thereby masking the actual misfire it detected - if in fact one actually existed.
This article will cover how to replace the detection module with a bypass connector, temporary preventing phantom misfires, or allowing diagnosis of an actual misfire.
It is important that is you are still running the catalyst, and chose to bypass the misfire detection, that the car is NEVER run with an actual misfire present, or fire might happen...
The kit of parts consisted of (amongst various screws and clips) a detection module, and a 'jump wiring harness'.
The detection module was fitted to the left-hand side wall of the boot box compartment.
The jump wiring harness basically routed the ECU connections to the injectors, coil packs, and O2 sensor through the detection module, where it could chose to interrupt them or not.
This was achieved by unplugging the relevant engine harness connector, plugging the ECU end of it into the jump harness, then the other end of the jump harness into the engine end of the engine harness - if that makes sense.
Complete removal of the system is simply a case of removing this jump harness, and re-connecting the engine harness connectors into their pre-recall positions.
I would not suggest complete removal, but a temporary/diagnostic bypass connector to replace the detection module would be of use (to me at any rate)...
First we need a connector, which can be had here for a massive £1.18:
Stock number 673-7799
OK its a PCB mountable connector, but it seems to be the only type available.
Next we need to connect the right pins together...
- Off to work this bit out - update in the next day or two**