ECM SYSTEM
WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, DM
1-166
DTC 172-Adaptive Learn Bank1 Low (Gasoline)
Diagnostic Aids
• If any other DTCs are present, diagnose those first.
• Oxygen Sensor Wire - Sensor may be mispositioned contacting the exhaust. Check for short to ground between
harness and sensor and on sensor harness
• Injectors - System will be rich if an injector driver or driver circuit fails shorted-to-ground. The system will also be
rich if an injector fails in an open position or leaks.
• Fuel Pressure - System will be rich if fuel pressure is too high. Check fuel pressure in the fuel rail during key-on,
engine off and during normal operating conditions.
• System Electrical Grounding - ECM and engine must be grounded to the battery with very little resistance allowing
for proper current flow. Faulty grounds can cause current supply issues resulting in many undesired problems
(causing sensors to provide bad information to the ECM).
• Internal mechanical engine damage causing lower than normal intake manifold vacuum
• MAP sensor that indicates pressure higher than true pressure
• Coolant Temperature Sensor - A sensor that indicates the engine is colder than actual engine temperature
• If all tests are OK, replace the HO
2S sensor with a known good part and retest.
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