Mazda B-Series 1997 Workshop Manual page 448

ON-BOARD DIAGNOSIS SYSTEM
FT
. .
~ e y ON.
Is fuel pump off?
STEP INSPECTION
10 Key ON. Wait five seconds.
/
No Go to step 23.
1
Repair short to power in power-to-pump or
FPM circuit.
Go to step 23.
11
Key OFF.
Install breakout box, leave PCM disconnected.
Disconnect fuel pump relay.
Measure resistance between FPM test pin 40 at breakout
box and power-to-pump pin at fuel pump relay connector
on power distribution box.
Is resistance less than 5.0 ohms?
Is fuel pump off?
Listen for motor noise from fuel pump.
Go to next step.
- -
Kev OFF. Disconnect fuel pump relay.
Yes Replace PCM.
Go to step 23.
Repair open circuit.
Go to step 23.
Key OFF. Yes Go to next step.
Disconnect inertia fuel shut-off switch.
- -
- -
Measure resistance between C and NC pins of switch.
No
1
Replace or reset inertia fuel shut-off switch.
Is resistance less than 5.0 ohms?
I
Go to step 23.
Key OFF.
Leave inertia fuel shut-off switch disconnected.
Disconnect fuel pump relay.
Measure resistance of power-to-pump between fuel pump
relay connector on power distribution box and inertia fuel
shut-off switch connector.
Is resistance less than 7.0 ohms?
Key
OFF.
Leave inertia fuel shut-off switch disconnected.
Disconnect fuel pump.
Is resistance between fuel pump motor ground circuit at
fuel pump connector and chassis ground less than
5.0 ohms?
Yes Reconnect fuel pump relay.
Go to next step.
Repair open in power-1.0-pump circuit
between inertia fuel shut-off switch and FPM
connection to circuit.
Go to step 23.
Yes Go to next step.
Repair open in fuel purnp ground circuit,
Go to step 23.
Key OFF.
Leave fuel pump and inertia fuel pump shut-off switch
disconnected.
Is resistance of power-to-pump circuit between inertia fuel
pump shut-off switch connector and fuel pump connector
less than 5.0 ohms?
Yes Go to next step.
I
Repair open circuit.
Go to step 23.
Key OFF.
Leave fuel pump and inertia fuel pump shut-off switch
disconnected.
Is internal resistance of fuel punip motor less than
10.0 ohms?
1
Yes
Fuel pump circuit is OK.
I
Replace fuel pump
Go to step 23.
Key OFF.
Disconnect fuel pump relay.
Is voltage between B+ circuit at fuel pump relay connector
on power distribution box and chassis ground greater than
10.5 volts?
Yes Go to next step.
I
Check fuse for B+ supply to fuel pump relay.
If
OK,
repair open in
B.+
circuit.
Go to step 23.
Is resistance between power-to-pump circuit at fuel pump
relay connector on power distribution box and battery
negative terminal less than 10.0 ohms?
1
19
1
Key OFF. Leave fuel pump relay disconnected.
/
Yes
Go to step 23.
Repair open in
between FPM splice and fuel pump relay.
Replace fuel pump relay.
I
I 1
Yes
20
Isolate fault and repair as necessary.
Go to step 23.
1
Key ON, engine off. Access FPM PID.
Perform FPM PID while performing the following:
Note: FPM PID will turn on when open or short to
power is detected.
-
Shake, wiggle, bend power-to-pump circuit between
pump relay and fuel pump, pump ground circuit, or
time. Go to "Intermittent Concerns."
FPM circuit to PCM.
=
page FT-69
-
Lightly tap pump, relay and inertia fuel shut-off switch.
I
1
Go to step 23.
I
1
Is fault indicatedtfound?
1 1