40 replies to this topic

[Sprocket]

Description of the relay pack control.

This is the likely scenario you will experience on the SPi engines, this however may differ slightly between years as Rover changed the wiring as far as i can see about 4 times. Slight changes may be experienced, but for the most its the same.

Coil side of relay pack (small connector)

+ve supply to the relay coils

The main relay is permenantly supplied with 12v (internal), the fuel pump relay is supplied with 12v from the IGN position on the key switch (white), the manifold heater relay coil is supplied with 12v when the main relay is energised (internal but common to brown pink), the starter relay coil has two options depending on year. One, the starter coil is supllied with 12v when the key switch is turnd to CNK (white with red). Two, the starter coil is supplied with 12v when the key switch is turned to CNK (white with pink). Note the latter, the wire from the starter switch is white with red, then changes to white with pink through the body to engine loom connector.

-ve supply to the relay coils.

The main relay is grounded by the ECU (white with pink), the fuel pump relay is grounded by the ECU (black with purple), the manifold heater relay is gounded by the ECU (black with pink), the starter relay has two options depending on year. One, the starter relay is grounded (black pin4). Two the starter relay is grounded by the alarm ECU ( white with red). Note the latter, the wire from pin4 of the relay pack changes from white with red to white with pink, through the body to engine loom connector.

Main switched power supply (large connector)

All four relays are fed with 12v from the battery (brown). Main relay switched live is brown with pink. Fuel pump switched live is brown with slate(grey). Manifold heater switched live is brown with blue. Starter switched live is brown with red.


Logic explained

When the key switch is turned to IGN 12v is supplied to the ECU on a white wire this powers the ECU. The ECU will then initiate the fuel pump for 10 seconds and then de activates it again if there is no further activity. Turn the key to CRK the starter is initiated (if the imobiliser/alarm is off, where fitted). Activity is recorded by the ECU on the Crank Position Sensor. The ECU then initiates the Main relay. This provides power to the ignition coil, stepper motor, purge valve solenoid, and ECU directly on the brown pink, and the injector via the ECU. The engine should now start. Once the RPM is above a predetermined RPM the manifold heater is initiated until the coolant temp measures 75c or more it is then de activated. The Main relay, and fuel pump relay, are the only ones to be energised when the engine is running and fully warmed up.

[seria]

Would it possible to post some pictures together with the explanation? I can take picture and send it to you if needed. So far i don't quiet follow as it involve so many relays.
Thanks.

[rocketbeta]

Description of the relay pack control.

This is the likely scenario you will experience on the SPi engines, this however may differ slightly between years as Rover changed the wiring as far as i can see about 4 times. Slight changes may be experienced, but for the most its the same.

Coil side of relay pack (small connector)

+ve supply to the relay coils

The main relay is permenantly supplied with 12v (internal), the fuel pump relay is supplied with 12v from the IGN position on the key switch (white), the manifold heater relay coil is supplied with 12v when the main relay is energised (internal but common to brown pink), the starter relay coil has two options depending on year. One, the starter coil is supllied with 12v when the key switch is turnd to CNK (white with red). Two, the starter coil is supplied with 12v when the key switch is turned to CNK (white with pink). Note the latter, the wire from the starter switch is white with red, then changes to white with pink through the body to engine loom connector.

-ve supply to the relay coils.

The main relay is grounded by the ECU (white with pink), the fuel pump relay is grounded by the ECU (black with purple), the manifold heater relay is gounded by the ECU (black with pink), the starter relay has two options depending on year. One, the starter relay is grounded (black pin4). Two the starter relay is grounded by the alarm ECU ( white with red). Note the latter, the wire from pin4 of the relay pack changes from white with red to white with pink, through the body to engine loom connector.

Main switched power supply (large connector)

All four relays are fed with 12v from the battery (brown). Main relay switched live is brown with pink. Fuel pump switched live is brown with slate(grey). Manifold heater switched live is brown with blue. Starter switched live is brown with red.


Logic explained

When the key switch is turned to IGN 12v is supplied to the ECU on a white wire this powers the ECU. The ECU will then initiate the fuel pump for 10 seconds and then de activates it again if there is no further activity. Turn the key to CRK the starter is initiated (if the imobiliser/alarm is off, where fitted). Activity is recorded by the ECU on the Crank Position Sensor. The ECU then initiates the Main relay. This provides power to the ignition coil, stepper motor, purge valve solenoid, and ECU directly on the brown pink, and the injector via the ECU. The engine should now start. Once the RPM is above a predetermined RPM the manifold heater is initiated until the coolant temp measures 75c or more it is then de activated. The Main relay, and fuel pump relay, are the only ones to be energised when the engine is running and fully warmed up.

I have a question, how would I test to see if one of the relays is not working? I pulled out the relay manifold and it smelled burnt. I'm asking the question because my 1996 Mini 1200cc (Fuel Injected, SPI) isn't starting and I wanted to confirm that the starter relay isn't out.

Thanks,

Anthony

[FlyingScot]

To help with the issues around the Relay Pack where it is maybe difficult to visualise.
 
This is for model YWB10022 the so called Yellow sticker version for SPi.
 
Whats inside the black box?
 
 YWB10022 Inside view.jpg   52.5K   588 downloads
 
Wiring connections
 
 YWB10022 Wiring Pin out.jpg   48.13K   591 downloads
Note the bottom right hand control connection (small plug) is a thick cable white/pink or white/red cable depending on whether you have an immobiliser or not.
 
Hopefully when read with Sprockets earlier words this will help.
 
You can test across the relay coils with a multimeter set to Ohms once the unit is out of the cars wiring. If you ignore the shunt resistors the coils themselves should be about 66ohms. Obviously of there is no reading across the tops of the pins you know the coil is burnt out.
Likewise you can test the contacts by operating manually and measuring the resistance.
 
FlyingScot

Edited by FlyingScot, 24 January 2014 - 12:12 PM.

[Uxmini]

Is it possible to repair the SPI Relay box? Mine is ticking and the starter no longer turns and the fuel pump is not running.If repair is not considered feasible where can a replacement be found?

Edited by Uxmini, 07 October 2016 - 12:59 PM.

[Uxmini]

...and...where can I get a wiring diagram for a 1991 Cooper with air conditioning?

[FlyingScot]

Is it possible to repair the SPI Relay box? Mine is ticking and the starter no longer turns and the fuel pump is not running.If repair is not considered feasible where can a replacement be found?

Usual issue is earthing. It is possible repair by replacing the open frame relays if you can find a local supplier.
You can buy new from minispares

FS

[Uxmini]

Thank you, FlyingScot.

[Mini Stripey]

Hi sprocket
Just read your write up on the workings of the relay unit, Im not very technical but your description was brilliant and easy to understand, hoping you can help me, 2 days of a spi not running, basically most occasions on starting fuel relay isnt cutting in, if you push it with your finger runs fine, from your write up it gets a negative from the ecu, if I dab a negative on the black purple wire pump cuts in and runs fine, am I on the right track thinking my ecu isnt giving the negative signal for some reason? Really hope you can help 2 days tinkering in the rain getting nowhere
Many thanks in advance for any help you may be able to give mike

[Sprocket]

If the ECU is not grounding the fuel pump relay coil, first check the crankshaft sensor.
 

Does the fuel pump run for a second or two when the ignition is turned to position II (IGN)? If yes then the ECU is OK, and it's likely a crankshaft sensor problem.

 

One other thing to check, does the main relay also pull in when ignition is turned to Position II (IGN)?

 

Stepper motor will motor the throttle full closed and back open again when ignition key off. If it doesn't there is a more fundamental problem than just the fuel pump relay.

[Mini Stripey]

Sprocket
Thank you so much for taking the time to reply.... since we last spoke my situation has got worse and I've spent three solid days trying to rectify
Sometimes it stars and runs fine for a while other times no start
As said before pushing the relay or dabbing earth on purple black wire and everything if perfect, I've replaced the crankshaft sensor I've cleaned the earth point near ecu I've cleaned earth from bulkhead to engine, I've connected jumpleads from negative battery and connected to earth points, and still it will only pull the relay in when it feels like it, I've swapped the ecu and immobiliser in dash and exactly the same fault, so I believe relay pack is fine, ecru and immobiliser fine, and earth points fine, I'm going out of my mind, it just seems the ecru isn't getting a good earth but I don't know where the ecru gets its earth from, I've spliced the purple black wire at the ecu plug and dabbed a earth to check ecru purple black wire is ok and works fine, there just seems no pattern, I removed the 18 way fuse box from the bulkhead and wiggled all connections and it started fine but could have been a coincidence, when key is turned the relay box triggers the fuel pump for a few seconds but when you crank the fuel pump relay doesn't activate.... I'm thinking the ecu isn't getting a good enough earth but I'm one step away from putting a match to it... and currently has no mot so can't take to auto eclectician, yesterday it ran ok for two hours so parked it up had mot at 9;30 this morning and yep.. wouldn't start.. the only thing I'm left with is to fit a switch on the dash wiring a earth to the purple black and turning the switch off and on when I want to drive it, but that's ideal....really really would appreciate another reply with a suggestion. I took the manifold off today to check wiring loom for damage but all looked perfect. Please help me .. many thanks in advance sprocket

[Mini Stripey]

How can I see the stepper motor opening the throttle? Should it open the butterfly. Don't believe that's happening, I have a spare motor

[Mini Stripey]

Main relay pulls in on ignition 2 - yes

[Mini Stripey]

If you could let me know the stepper motor sequence I will concentrate on that next I guess, I don't Rember seeing it do much

[Sprocket]

Witnessed very similar problem only a few weeks back on an MPi. what we found in the end was the terminal in the small connector on the relay pack was damaged and not making contact.

 

Re stepper motor, you should hear the stepper motor clicking when you turn off the ignition as it drives the throttle full closed and then hear it gently open the throttle again. If you get someone to turn the ignition on and off again while you watch the throttle shaft and stepper motor actuator you should see it close the throttle and then open it again.