The car

MY93 WRX saloon

The problem...

Right then, here goes...........

Turn igmition on, no check engine light, no cat on fire light....

Changed Main Relay, twice, fuel pump relay once, ecu once

Checked voltage on the loom for the main relay. The two pins that receive power direct from the fuse box are both circa 11 - 12v. The pin that receives power from the ecu (Pin 5, D44) is only reading 9.** Volts. Did a continuity test on this pin between the main realy and the ecu, everthing good.

Hooked Main relay upto the battery, directly (as per workshop manual) Hear clicking noise presume thats ok.

All fuses have been checked.

Anything I've missed???

Mike

 

Hi Mike. I had the exact same problem recently. Turned out to be the green 30 amp fuse in the engine bay fuse box. The rear most one. I checked mine three times with a multimeter and it checked out fine every time. Changed it and my scooby fired up straight away and no problems since. Give it a go. Cheers. Mark.

 

Cheers for the reply, I've swapped it for another one, but still no joy. Where did you get your replacement?

Mike

 

???????????

 

I wish i could help Mike...... any advances..??

 

11-12V is not good enough for a 12V relay, 12V relays require 12V as a MINIMUM to power the electromagnet enough to pull the contact across. I have had this before on a bike I worked on. The regulator/rectifier was not charging the battery properly and, as a result, the battery output voltage was less than 12V. The relay would not work properly until a proper 12V was applied to it. The relay may be fine when 12V is applied to it but the supply to it from the battery may be resistive (corroded wire, dirty contact etc) and dropping the voltage below the magic 12V.

I'd check your battery output and, if necessary, charge it, then check that your alternator is putting a decent charge across the battery. 14.5V approximately.

Cheers

Grim

 

Strange one

Ok is the car starting/driving?

Does thje car have an aftermarket alarm immoboliser?

Has this problem suddeny occured,or after something was tampered with?

Not being funny but are you sure the bulbs are ok?

hope you got hte problem fixed

 

have you checked the loom earth to the manifold and the engine loom connectors by the battery. Both would give these symptoms

Rob

 

Cheers for the response guys.

The car was running fine until it completed a rolling road session a couple of weeks ago. On the way home, five minutes after leaving (prob an hour after being on the rollers as it was a power run group type thing) there was a couple of load bangs, followed by a bit of black smoke and a flame. Tried to restart but noticed the check engine light and cat on fire light were both inop. Had the car brought home by the AA and here we are...

Rob

I'll be checking that this morning, thanks

 

Looked into this a bit more now.

It seems the main relay gets its switch feed from the ecu. The manual says that it is the 'self shutdown control' Measureds the voltage coming out of this and it doesnt seem to go over 9.97V? Obviously the relay needs at least 10 to work.

Anyone every heard of this self shutdown control? What would cause it to malfunction?

Mike

 

Still struggling

 

Update

I've now put a seperate 12v feed (from an ignition switched live) to the relay.

I know get all four lights (cof, oil, batt, cel) engine turns over, but wont fire??

Any ideas now????????

 

possible ecu fried?

remove and check the board for problems.. and check the wiring from ecu.

Simon