The MIL, the DTC, the Temporary DTC, and the freeze frame data can be cleared by using the scan tool Clear
command or by disconnecting the battery.
DTC P0172 (45): ADVANCED DIAGNOSTICS
DTC P0172: FUEL SYSTEM TOO RICH
Fig. 38: Air/Fuel Ratio - Graph
General Description
The engine control module (ECM)/powertrain control module (PCM) detects the oxygen content in the exhaust
gas from the air/fuel ratio (A/F) sensor (sensor 1) signal voltage, and it uses fuel feedback control to maintain
the optimal air/fuel ratio. The air/fuel ratio coefficient for correcting the amount of injected fuel is the short term
fuel trim. The ECM/PCM varies short term fuel trim continuously to keep the air/fuel ratio close to the
stoichiometric ratio for all driving conditions. Long term fuel trim is computed from short term fuel trim and is
used to regulate long term deviation from the stoichiometric air/fuel ratio, which occurs when fuel metering
components deteriorate with age or system failures occur. In addition, long term fuel trim is stored in the
ECM/PCM memory and is used to determine when fuel metering components malfunction. When long term
fuel trim is higher than normal, which is about 1.0 (0 %), the amount of injected fuel must be increased, and
when lower than normal, it must be decreased. If long term fuel trim is lower than normal (too rich), a
malfunction in the fuel metering components is detected and a DTC is stored.
Monitor Execution, Sequence, Duration, DTC Type, OBD Status
MONITOR DESCRIPTION
Enable Conditions
Execution
Once per driving cycle
(1)
Sequence
None
Duration
11.2 seconds
DTC Type
Two drive cycles, MIL ON
OBD Status
N/A
(1)
The malfunction judgment is cleared when it is judged as normal under the same driving conditions
in which the malfunction is detected.
2007 Honda Element EX
2007 ENGINE PERFORMANCE Advanced Diagnostics - Element