Reset ECU Euro 4 Classic
Posted: Fri Sep 13, 2019 1:17 pm
While I had the engine side case off the other day to change the gearing I made the mistake of switching on to check the brake light as I was putting it back together.
I forgot that I had the O2 sensor disconnected so the MIL showed a fault and, of course, continued to show a fault even after I had re-connected the O2 sensor.
A lot of trawling the net came up with this fix which worked but I had to try a few times to get it to work.
The grounding jumper is near the ECU and is the one that's not connected to anything.
You have to release the throttle JUST before it starts blinking the code - time this a couple of times so you can get the timing right.
"Start with key off and set the kill switch to the run position . This is so when you do turn the key on, the Mil light comes on and the fuel pump as it normally would.
Connect a grounding jumper from the purple wire at the ECU to chassis ground.... to the motor or an unpainted area of the frame or to the negative side of the battery.
Fully open the throttle.
With the kill switch in the run position, turn the key on. At this point the Mil light and pump will come on as normal.
After the Mil light goes out, and BEFORE it comes back on, to start blinking the codes.... release the throttle. This period is more like ten seconds between the time the Mil light comes on initially and when the Mil light will start blinking it's codes. You have to release that throttle RIGHT before the Mil light starts going into the code blinks it seems.
The Mil light blinks a couple of times... and no more codes.
You can test to make sure the codes are gone, by simply turning the key back off. Disconnect the grounded purple wire, then..
Reattach the purple wire to chassis ground.
With the kill switch set to the run position, turn the key on.
The Mil light and fuel pump will come on as normal, then go back off.
Wait ten or more seconds , and if the mil light does not start blinking again, the codes are gone . If you had a code, that Mil light would start to blink again after 10-12 seconds. If it dosn't start blinking again after that time goes by ? You good it seems !!"
I forgot that I had the O2 sensor disconnected so the MIL showed a fault and, of course, continued to show a fault even after I had re-connected the O2 sensor.
A lot of trawling the net came up with this fix which worked but I had to try a few times to get it to work.
The grounding jumper is near the ECU and is the one that's not connected to anything.
You have to release the throttle JUST before it starts blinking the code - time this a couple of times so you can get the timing right.
"Start with key off and set the kill switch to the run position . This is so when you do turn the key on, the Mil light comes on and the fuel pump as it normally would.
Connect a grounding jumper from the purple wire at the ECU to chassis ground.... to the motor or an unpainted area of the frame or to the negative side of the battery.
Fully open the throttle.
With the kill switch in the run position, turn the key on. At this point the Mil light and pump will come on as normal.
After the Mil light goes out, and BEFORE it comes back on, to start blinking the codes.... release the throttle. This period is more like ten seconds between the time the Mil light comes on initially and when the Mil light will start blinking it's codes. You have to release that throttle RIGHT before the Mil light starts going into the code blinks it seems.
The Mil light blinks a couple of times... and no more codes.
You can test to make sure the codes are gone, by simply turning the key back off. Disconnect the grounded purple wire, then..
Reattach the purple wire to chassis ground.
With the kill switch set to the run position, turn the key on.
The Mil light and fuel pump will come on as normal, then go back off.
Wait ten or more seconds , and if the mil light does not start blinking again, the codes are gone . If you had a code, that Mil light would start to blink again after 10-12 seconds. If it dosn't start blinking again after that time goes by ? You good it seems !!"
