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DTC 522636 Short Term Fuel Lean, Bank 1
Conditions for Setting the DTC
The short term fuel correction has a range of ± 25%. If the correction reaches the upper or lower limit, it will
then try an additional 2% change to watch for an O2 switch. If the sensor switches with the additional 2%, a
short term fuel correction code will be set. If the sensor does not switch with the additional 2% change, the
system will set a code for a sensor that fails to switch rich or lean.
Circuit Description
The system monitors the O2 sensor to ensure that the fuel control is functioning properly. The HEGO
sensor is mounted in the exhaust system downstream of the engine. The HEGO sensor is used to meas-
ure the amount of oxygen present in the exhaust stream and communicates that to the ECM via an
electrical signal. The amount of oxygen present in the exhaust stream indicates whether the fuel air ratio is
rich or lean. If the HEGO sensor signal indicates that the exhaust stream is rich, the ECM will decrease or
lean the fuel mixture by reducing the short term fuel correction value which reduces the injector on-time
supplying less fuel. If the mixture is lean, the ECM will richen the mixture or increase the short term fuel
correction value which will increase the pulse width to the injectors. Under normal steady operation the
short term fuel correction value should move up and down approx. 5%. This 5% movement may range
within a plus 25 to minus 25 percent window. The ECM continuously monitors the HEGO sensor output. If
a rich or lean condition is present for an extended period of time and if the ECM cannot correct the condi-
tion, the ECM will set a diagnostic code and turn on the MIL light in the dash. NOTE: The HEGO sensor is
sensitive to silicone and silicone-based products and can become contaminated. Avoid using silicone sea-
lers or hoses treated with silicone lubricant in the air stream or fuel supply lines.
Diagnostic Aids
Low fuel pressure
Partially blocked fuel injectors
Manifold vacuum leaks
Defective O2 sensor
A misfire on one or more cylinders
Exhaust leak ahead of the O2 sensor
Faulty MAP sensor
Содержание 3.0L GM
Страница 4: ...4 ...
Страница 5: ...5 General Information ...
Страница 9: ...9 Maintenance ...
Страница 16: ...16 ...
Страница 17: ...17 LPG Fuel System ...
Страница 18: ...18 LPG FUEL SYSTEM OPERATION ...
Страница 25: ...25 LPG Closed Loop Schematic ...
Страница 26: ...26 ...
Страница 27: ...27 LPG System Diagnosis ...
Страница 35: ...35 Fuel Symptom Diagnostics ...
Страница 51: ...51 Electrical Section ...
Страница 52: ...52 ...
Страница 53: ...53 DST Diagnostic Scan Tool ...
Страница 59: ...59 Select the USB button then click the OK box Click on the Search attached device box ...
Страница 67: ...67 When connected the live data stream appears in the Value column ...
Страница 78: ...78 ...
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Страница 81: ...81 Engine Wire Schematic ...
Страница 82: ...82 2011 3 0L GM Engine IMPCO Emission Certified LPG Fuel System ...
Страница 83: ...83 ...
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Страница 85: ...85 Engine Wire Harness Repair ...
Страница 89: ...89 Diagnostic Trouble Codes DTCs ...
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Страница 237: ...237 Servicing the Fuel System ...
Страница 254: ...254 ...
Страница 255: ...255 LPG Parts Diagram ...
Страница 256: ...256 THROTTLE BODY ASSEMBLY ...
Страница 258: ...258 FUEL RAIL INJECTORS ...
Страница 260: ...260 REGULATOR ASSEMBLY ...
Страница 262: ...262 HOSE ASSEMBLIES COOLANT VACUUM FUEL ...
Страница 264: ...264 THERMOSTAT HOUSING ...
Страница 266: ...266 ENGINE CONTROL MODULE ...
Страница 267: ...267 ENGINE CONTROL MODULE Item Description Qty IMPCO Part Number 1 ECM Liugong 1 A11 173 ...
Страница 268: ...268 SENSORS 4 1 3 6 5 2 7 ...
Страница 270: ...270 DISTRIBUTOR ...
Страница 272: ...272 FUSE BOX BRACKET ...
Страница 274: ...274 IGNITION COIL ...
Страница 275: ...275 IGNITION COIL Item Description Qty Part Number 1 Coil Ignition 1 7245530 ...
Страница 276: ...276 MANIFOLDS ...
Страница 278: ...278 WIRE HARNESS FUSES FUSE BOX COVER Fuse Box Layout 4 ...
Страница 280: ...280 PCV VENT VALVE ...
Страница 282: ...282 MISCELLANEOUS ENGINE ...
Страница 284: ...284 ALTERNATOR ...
Страница 286: ...286 STARTER ...
Страница 291: ...291 ...
Страница 292: ...292 3 0L UPPER ...
Страница 294: ...294 3 0L LOWER ...
Страница 298: ...298 ...
Страница 299: ...299 Labor Time Guide ...
Страница 317: ...317 Definitions ...
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Страница 323: ...323 Appendix ...
Страница 327: ...327 DTC SPN FMI Chart ...