Purge Flow Sensor (Pf) Circuit Malfunction - Mazda B-Series 1997 Workshop Manual

FT
ON-BOARD DIAGNOSIS SYSTEM
Diagnostic trouble code
No. P1444, P1445
Symptom
PURGE FLOW SENSOR (PF) CIRCUIT MALFUNCTION
PF circuit voltage high or low.
STEP
1
INSPECTION
I
ACTION
Key OFF.
/
For DTC P1444:
Inspect for damaged or pushed out pins, corrosion, loose
1
Go to next step.
wlres at PCM or purge flow sensor connector. Repair or
1
For DTC P1 445:
replace if necessary.
Go to step 6.
1
2
3
Follow direction in Action.
Key ON, engine off.
Is PF PID voltage less than 0.14 volts or greater than 4.89
volts?
Key OFF.
Disconnect purge flow sensor connector.
Is resistance between PF SIG (pin 2) and PWR GND
Yes
4
- - ~ -
Go to next step.
. - . .-
~-
(pin 3) on sensor less than 25.50 ohms?
No
,
Go to next step.
I
K e y
Disconnect purge flow sensor connector.
I
Install breakout box, leave PCM disconnected.
No
1
Repair short between PF SIG and PWR GND.
Is resistance between PF SIG test pin 11 and PWR GND
i
(
Go to step 13.
test pin 241103 at breakout box greater than 10,000 ohms?
- - -
I _ - -
~. . -
No
!
Go to step 5.
-
Yes Replace sensor.
Go to step 13.
-
~
- ~ - - -
5
1
Key ON, engine off. Yes
;
Isolate fault and repair as necessary.
6
7
8
Access PF PID.
;
Go to step 13.
Is fault indicated while performing the following?
- Lightly tap on sensor or wiggle PF sensor connector
Is voltage between PF SIG circuit at sensor and battery
ground terminal greater than 10.5 volts?
9 Key OFF.
Leave PF sensor disconnected.
Install breakout box, leave PCM disconnected.
Key ON, engine off.
/
Is voltage between PF SIG test pin 11 and PWR GND test
pins 2411 03 at breakout box greater than 10.5 volts?
No
I
Unable to duplicate andlor identify fault at this
No
I
G~
to
step
1
Yes
/
Repair short between PF SIG and VPWR
!
j circuit.
I
/
Go to step 13.
No
I
Replace PCM.
Go to step 13.
I
and vehicle harness. A fault is indicated by a sudden
j
time.
change in PF PID voltage (less than 0.14 volts).
Go to "Intermittent Concerns."
I
@
page FT-69
10
.
-
11
12
13
Key ON, engine off.
Access PF PID.
Key OFF.
j
Yes Go to next step.
Disconnect PF sensor connector.
I
Install breakout box, leave PCM disconnected.
Measure resistance between PF SIG test pin 11 at
/
No Repair open in PF SIG circuit.
breakout box and PF SIG circuit at sensor.
Go to step 13.
Is resistance less than 5.0 ohms?
I
--- -
- . .-
~
~-
Key OFF.
Leave PF sensor and PCM disconnected.
Replace PCM.
~
Go to step 13.
Is the resistance between PWR GND test pins 2411 03 at
b -
~
-
breakout box and PWR GND circuit at sensor connector
No Repair open in PWR GND circuit.
less than 5.0 ohms?
I
Go to step 13.
Key ON, engine off.
Yes Isolate fault and repair as necessary.
Access PF PID.
(
Go to next step.
Is a fault indicated while performing the following?
- Lightly tap on PF sensor or wiggle sensor connector
No Go to "Intermittent Concerns."
and vehicle harness.
I
e
page FT-69
Perform After Repair Procedure to ensure customer's concern has been resolved.
Yes Go to next step.
MF1859-C 6BUOFT-088
FT-136
Is PF PID voltage greater than 4.89 volts?
I
No Go to step 12.
.
-
-
~
Key OFF. Yes
,
Go to next step.
Disconnect PF sensor connector.
Measure resistance between PF SIG (pin 2) and VPWR
I
(pin 1) on purge flow sensor at room temperature
No
I
Replace sensor.
(55 to 80°F [I31 to 176"CI).
I
Go to step 13.
Is resistance between 60 and 200 ohms?
1
Leave PF sensor disconnected.
1
Key ON, engine off.
Yes
:
Go to next step.