BMW 1999-2005 M3 Service Manual page 114

On-Board Diagnostics
BMW P-code
code
245 P1423
246 P1421
247 P1432
248 P1184
249 P1185
250 P0440
20 of 20
Fault type and Signal type and
function range
Secondary air Input analog
injection (Bank 1), (0-5V)
flow too low
Secondary air Input analog
injection (Bank 2), (0-5V)
flow too low
Secondary air Input analog
valve stuck open (0-5V)
Post-cat sensor; Input analog
signal after decel (0-5V)
phase not
plausible; (Bank 1)
Post-cat sensor; Input analog
signal after decel (0-5V)
phase not
plausible; (Bank 2)
Functional check Input analog
purge valve (0-5V)
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Explanation
Checks to see if oxygen
sensor reacts to increase in
unmetered airflow generated
by secondary air pump
operation. Oxygen sensor
must sense lean condition or
fault will set.
Checks to see if oxygen
sensor reacts to increase in
unmetered airflow generated
by secondary air pump
operation. Oxygen sensor
must sense lean condition or
fault will set.
Checks to see if oxygen
sensor reacts to increase in
unmetered airflow generated
by secondary air pump
operation. Oxygen sensor
must sense lean condition or
fault will set.
Signal is checked for a lean
signal in decel and a
transition between lean to rich
after decel
Signal is checked for a lean
signal in decel and a
transition between lean to rich
after decel
This functional check looks
for reaction of oxygen sensor
signal during canister
purging. Oxygen sensor, air
flow meter and RPM values
must react to purging of
canister.
2/25/2009 11:23 PM