Ecu Reset Procedure

[Guest Citroen CT]

hello all i work in the dealer network and upon reading alot of the posts you may find this info useful

 

How to reset all ecu's

 

this procedure is called a power latch

 

firstly turn on the ignition not engine running,

open bonnet remove battery positive lead and then turn off ignition.

then touch the positive lead to earth,this powers down all ecus and resets erasing intermittent faults in the process.then reconnect the battery lead.

if the vehicle doesnt start straight away leave the ignition on for 2-3 mins as it has gone into anti scanning mode.

 

IMPORTANT PLEASE READ CAREFULLY

upon starting the vehicle DO NOT TOUCH THE THROTTLE allow vehicle to idle until cooling fans cut in to allow the engine ecu to reset correctly and reprogramme the learning curve,then drive in all gears upto 4,000 rpm accellerating steadily.

 

as stated this resets all ecus so any electrical faults caused by conflict errors in programming will be erased and fixed.if the fault is still evident there is a problem that will need further diagnosis

[safari]

Do you mean touch the postive lead onto the negative lead? Won't this fry the alternator or electrics? Sounds dangerous -

 

Presumably you touch it very quickly so as not to cause any probs.

[Randombloke]

Do you mean touch the postive lead onto the negative lead? Won't this fry the alternator or electrics? Sounds dangerous -

 

The engine is not running and the battery is totally disconnected.

 

You are touching -ve to+ve to remove and remaining voltage held up by capacitance and guarantee total clearing of all old values AIUI.