Fault Code Cross-Reference Help Required

addo · Unread post by **addo** » 04 Jan 2010, 06:07

Among others described more explicitly, I've logged the following codes, according to the newer scan tool (Autel MaxiDiag):

250016
25001B
250020

All say to see the manufacturer for more info!

Car is stumbling and throwing a regular code "Richness regulation fault" that it describes as intermittent. It also logged in capitals, RICHNESS ADAPTATION (ADDITIVE) - any help on this? I'm thinking the O2 sensor is one culprit, at 155000km.

A semi-related aspect: The auto trans throttle position sensor readout I get from the scanner (not the regular TPS readout) goes from 9% (restive pedal) to 88% (pedal fully depressed, HARD). Anyone else have a similar reading on their auto trans throttle pot?

Thanks, Adam.

Edited to correct spelling of title!

DickieG · Unread post by **DickieG** » 04 Jan 2010, 06:24

Adam, what car/engine are you talking about?

addo · Unread post by **addo** » 04 Jan 2010, 06:32

Sorry; heatstroke!

'99 Xantia Break 2.0 16V w/Bosch MP5.2 and AL4.

DickieG · Unread post by **DickieG** » 04 Jan 2010, 21:16

Those fault code numbers aren't listed in the Citroën diagnosis manual but what the manual does state is that the ECU must be re-initialised after any of the following;
disconnection of the battery,
disconnection of the ECU or the supply relays,
replacement of the idle regulation stepper motor or throttle potentiometer.

Failure to re-initialise the ECU causes the following running problems, engine snatching,
engine stalling on returning to idle
engine stalls on starting

To re-initialise the ECU switch off the ignition, then switch it on.
wait 3 seconds before starting the engine.

Also auto-adaptation of the richness.
engine hot +60°C
road test the vehicle for a minimum of 15 minutes, making use of the various engine speeds, in particular,
from 2500 to3500 rpm.
idling speed
full throttle (for 2 seconds)

The above is worth a try before delving deeper or spending money, Citroën must state it for a reason.

BTW "Heatstroke" are you having a laugh? It was -7°C outside my place this morning

addo · Unread post by **addo** » 04 Jan 2010, 21:49

Should have said - I do the ECU thing (key on, wait, then start) as a matter of course every few days.

Having trouble holding a signal from the engine ECU to my scanner - it seems to either not connect fully, or soon drop out. Wanted to get some live data screenshots.

Another Lexia vs "MaxiDAS" quessie: When I put the AL4 into gear (other than N or P) the reading for AT input speed nulls, but RPM are still displayed. Do you see that same quirk?

Regards, Adam.

DickieG · Unread post by **DickieG** » 04 Jan 2010, 22:09

addo wrote:Another Lexia vs "MaxiDAS" quessie: When I put the AL4 into gear (other than N or P) the reading for AT input speed nulls, but RPM are still displayed. Do you see that same quirk?

Can't say I've noticed or looked for it TBH.