Briggs & Stratton VANGUARD 810 EFI Repair Manual page 21

Section 2: Troubleshooting DTCs
Step
1. Disconnect and reconnect O
(Black) connectors.
2. Turn Ignition ON, Engine OFF.
1
3. Clear codes.
4. Turn Ignition OFF, and then back ON.
5. Does DTC return?
1. Turn Ignition OFF.
2. Back probe (using fused patch cord) terminal A (Red
wire) on engine side of O
3. Connect terminal A back probe to red meter test
lead on DVOM.
4. Back probe terminal D (Brown wire) on engine side
2
of O sensor connector.
2
5. Connect terminal D back probe to black meter test
lead on DVOM.
6. Set DVOM to read volts DC.
7. Turn Ignition ON, Engine Off.
8. Does DVOM read 12.2-13.5 volts DC?
1. Turn Ignition OFF.
2. Remove probe from terminal A, and back probe
terminal B (White/Green wire) on engine side of O
3
sensor connector.
3. Turn Ignition ON, Engine OFF.
4. Does DVOM read 12.2-13.5 volts DC?
1. Turn Ignition OFF.
2. Remove probe from terminal B, and back probe
4 ECM connector terminal J2-07 (White/Green wire).
3. Turn Ignition ON, Engine OFF.
4. Does DVOM read 12.2-13.5 volts DC?
Are both O
5
mated?
A B C D
A B D
Figure 2-6 O Sensor Connector.
2
DTC P0031 Oxygen Sensor (HO
Scan and Non-Scan Diagnostics
Action
sensor and ECM J2
2
sensor connector.
2
sensor and ECM J2 connectors fully
2
1
10
Figure 2-7 ECM J2 Connector (Black).
) Heater
2
Yes
Go to step 2.
Go to step 3.
2 Go to step 4.
Both EFI wire
harness and O
sensor are good.
Repair or replace
EFI wire harness.
9
18
J2-07
No
Problem
corrected.
Perform visual and
continuity check of
Main Power Relay
and 20 amp
Battery fuse (Yel-
low).
Either there is no
power from fuse
block or not getting
ground thru 5 volt
return circuit.
Replace O sensor.
2
Go to step 5.
2
Connect
connectors.
Main Power Relay
Battery Fuse
Figure 2-8 Fuse/Relay Block.
17