Dtc P0131 Signal Voltage Low (Non-Scan Diagnostics) - Briggs & Stratton VANGUARD M490000 Repair Manual

DTC P0131 Signal Voltage Low (Non-Scan Diagnostics)

Step
1 1. Disconnect and reconnect HO
connectors.
2. Turn Ignition ON, Engine OFF.
3. Clear codes.
4. Turn Ignition OFF, and then back ON.
5. Does DTC return?
2 1. Turn Ignition OFF.
2. Back probe terminal C (Grey/Black wire) of HO
connector.
3. Connect terminal C back probe to red meter test lead on DVOM.
4. Back probe terminal D (Brown wire) of HO
5. Connect terminal D back probe to black meter test lead on
DVOM.
6. Set DVOM to read volts DC.
7. Start and run engine for at least 2 minutes.
8. With engine running, observe voltage on DVOM.
9. Is reading 600 – 950 millivolts DC?
3 1. Turn Ignition OFF.
2. Remove probe from terminal C, and back probe ECM connector
terminal J2-17 (Grey/Black wire).
3. Start and run engine.
4. Observe voltage on DVOM.
5. Is reading 600 – 950 millivolts DC?
HO Sensor Connector
2
Action
sensor and ECM J2 (Black)
2
sensor
2
sensor connector.
2
Yes
Go to step 2.
HO sensor OK.
2
HO sensor OK.
2
ECM J2 (Black) Connector
No
Problem corrected.
2
Go to step 3.
Verify that both
HO sensor and ECM
2
J2 (Black) connectors
are fully mated.
NOTE: If reading is
below 300 millivolts DC,
inspect exhaust system
for cracks or leaks
between muffler and
cylinder head (gaskets).
If everything is OK,
replace HO sensor.
2
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