Mazda B-Series 1997 Workshop Manual page 460

ON-BOARD DIAGNOSIS SYSTEM
FT
TEST PIN 65 DPFE SIG
-
DIFFERENTIAL
TEST PIN 91 SIG RTN
-
PFE (DPFE)
TEST PIN 90 W V R E F
-
SENSOR
CONNECTOR
*TEST PINS LOCATED ON BREAKOUT BOX
(VIEW FROM PIN SIDE)
APPLY (VIEW FROM PIN SIDE)
VACUUM TO
TEST PINS LOCATED ON BREAKOUT BOX
MF1708-C
Diagnostic trouble
code No. PO402
1
EGR SYSTEM
Symptom
1
Self-test has detected EGR flow at idle.
STEP INSPECTION
Key OFF. Yes
Disconnect vacuum hose from EGR valve and plug hose.
~
Run KOER self-test.
Is KOER DTC PO402 output, or unable to run KOER
self-test due to engine stall or no start?
L-
-
ACTION
lnspect pressure hoses first for pinching and
icing. If OK, inspect EGR valve and hose for
signs of contamination, unusual wear, carbon
deposits, binding and other damage.
Go to step 13.
I
Reconnect vacuum hose.
1 1
/
Go to next steo.
EGR vacuum hose connected.
Run KOER self-test.
Is KOER DTC PO402 output or unable to run KOER
self-test due to engine stall or no start?
1
Yes
1
Go to next step.
No
I
lnspect pressure hose!; for pinching and icing.
)
If OK. go to step 9.
1
Yes
1
Go to next step. 3
1
Repair or replace hoses.
I
Go to step
13.
Are vacuum hoses OK?
Key OFF.
Disconnect pressure hoses at CIPFE sensor. Go to step 13.
Connect a hand vacuum pump to downstream pickup
marked "REF on DPFE sensor.
Key ON, engine off and access DPFEGR PID.
Apply 8-9 in-Hg vacuum to DPFE sensor.
+
-
PID voltage should be above 4.0 volts.
to DPFE sensor.
Quickly release vacuum from sensor.
Go to next step.
-
PID voltage should drop to less than 1 volt in less
than
3
seconds.
Does DPFEGR PID indicate a fault in DPFE sensor? - - -
FT-I 1 5