Mazda B-Series 1997 Workshop Manual page 429

ON-BOARD DIAGNOSIS SYSTEM
(
STEP
I
INSPECTION ACTION
Key
ON,
engine running.
Access MAF V PID.
Is MAF V PID between 0.34 and 1.96 volts?
-
Yes Unable to identify fault at this time.
Go to "Intermittent Concerns."
MAF SIG or MAF RTN is open or shorted
together in PCM. Replace PCM.
Go to step 21.
Start engine and bring to idle.
Note: If a KOER DTC PO505 is present, go to DTC
charts. If stabilized idle is not at least 700 rpm, go to
Diagnostic Index.
For 2.3L A m If vehicle stalls and cannot maintain idle,
replace PCM.
Run at 1500 rpm for 5 seconds, and bring it back to idle.
Access MAF PID (MAF PID should be greater than
3.90V).
Key OFF.
Disconnect MAF sensor and jumper PWR GND (B) and
MAF RTN (TILB) pins at MAF sensor connector.
Key ON, engine running.
Again access MAF PID.
Did MAF PID drop from the previous reading to below
0.39 volts?
Yes MAF SIG shorted to VPWR in MAF sensor.
Replace MAF sensor. Remove jumper.
Go to step 19.
No
'
Remove jumper. Go to next step.
Key OFF.
MAF sensor disconnected.
Install breakout box, leave PCM disconnected.
Key ON, engine off.
Is the voltage between MAF SIG test pin 88 and PWR
GND test pin 24 or 103 at breakout box greater than
10.5 volts?
Key OFF.
Leave MAF and PCM disconnected.
Disconnect scan tool or NGS.
Is the resistance between MAF SIG test pin 88 and
VPWR test pin 71 or 97 at breakout box greater than
10,000 ohms?
Yes Repair short between MAF SIG and power in
circuit.
Go to step 21.
I
NO GO to next step.
Yes MAF SIG shorted to power in PCM.
Replace PCM and go to next step.
Repair short between MAF SIG and VPWR
in circuit.
Go to next step.
(
21
(
Perform After Repair Procedure to ensure customer's concern has been resolved.
6BUOFT-057
TEST PIN 24/51/76/77/103 BIW B PWRfGND VEHICLE
L
FROM POWER RELAY
r
1
-
HARNESS
CONNECTOR
TEST PIN 71/97 Q R EXTENSION
TEST PIN 88
0
LBlR MAF SIG
TO MASS AIR
FLOW (MAF)
SENSOR
TEST PIN 36
0
Tf LB MAF RTN CONNECTOR
(VIEW FROM PIN SIDE)
TEST PINS LOCATED ON BREAKOUT BOX