Pinpoint Tests AM: The Check Fuel Cap Message Center Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test AM: The Check Fuel Cap Message Center Indicator Is Never/Always On

Normal Operation

The PCM continuously monitors the fuel level and retains the last updated value prior to the ignition switch being placed in the OFF position. After the ignition switch is placed in the ON position a new fuel level is taken and compared to the level recorded at ignition off. If the fuel level has increased, a flag sets in the PCM indicating the vehicle was refueled. If the Evaporative Emission (EVAP) monitor detects a gross leak while the refueling flag is set, a loose fuel filler cap or an incorrectly sealed fuel tank filler pipe (if equipped) is suspected and the PCM sets DTC P0457. When the PCM sets the DTC, the PCM sends the Instrument Panel Cluster (IPC) a check fuel cap message center indicator on request.

If the check fuel cap request is missing for less than 5 seconds, the check fuel cap message center indicator remains in the last indication state (on or off), based upon the last known message received. If the check fuel cap request is missing for more than 5 seconds or more, the IPC sets DTC U0100:00 in continuous memory and defaults the check fuel cap message center indicator inactive (off).

NOTE: If DTC U0100:00 sets in the IPC, other observable symptoms may be an inoperative speedometer, tachometer or odometer.

This pinpoint test is intended to diagnose the following:

- Message center concern
- Evaporative emission system concern
- PCM
- IPC

PINPOINT TEST AM: THE CHECK FUEL CAP MESSAGE CENTER INDICATOR IS NEVER/ALWAYS ON

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AM1 VERIFY THE OPERATION OF THE DOOR AJAR MESSAGE CENTER WARNING INDICATOR

- Close all doors then open the LH front door.
- Ignition ON.

- NOTE: If multiple warnings are present, the message center cycles through each of the warning indicators. Allow the displays to cycle through each display while determining whether the door ajar message center warning indicator is active.

- Observe the message center.
- Is the door ajar message center telltale warning indicator active?

Yes
GO to AM2.

No
GO to Pinpoint Test AN. Pinpoint Tests AN: The Door Ajar Message Center Warning Indicator Is Never/Always On

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AM2 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST

- Check for recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.
- Is PCM DTC P0457 recorded?

Yes
If the check fuel cap message center indicator is always on, REFER to Computers and Control Systems. If the check fuel cap message center indicator is never on, GO to AM3.

No
If the check fuel cap message center indicator is always on, INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation. If the check fuel cap message center indicator is never on, the system is operating normally at this time. If the fuel cap was left off and the check fuel cap message center indicator did not turn on, driving conditions may not have allowed for the PCM to confirm an EVAP leak and message the IPC to turn on the check fuel cap message center indicator.

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AM3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST

- Check for recorded IPC DTCs from the self-test.
- Is DTC U0100:00 recorded?

Yes
GO to Pinpoint Test BA. Pinpoint Tests BA: DTC U0100:00

No
INSTALL a new PCM. REFER to Electronic Engine Controls - Gasoline Engines Service and Repair. TEST the system for normal operation.

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