Toyota CH-R Service Manual: Precaution

PRECAUTION

FUEL RECEIVER GAUGE OPERATION

(a) OPERATION

The combination meter assembly uses the fuel injection volume signal from the ECM, fuel sender gauge assembly to detect the amount of fuel remaining in the fuel tank assembly. Each gauge assembly has a variable resistor whose resistance changes according to the amount of fuel remaining. The gauge assemblies receive voltage from the combination meter assembly and change the voltage based on the resistance that changes according to the amount of fuel remaining in the fuel tank assembly. The combination meter assembly receives a fuel injection volume signal from the ECM and detects the voltage between each variable resistor and each resistor in the combination meter assembly, and operates the fuel receiver gauge.

(b) FUEL RECEIVER GAUGE READING

(1) During normal driving:

As the fuel level in the fuel tank assembly changes when driving on a hill or applying brakes, the fuel receiver gauge reading is updated according to the fuel injection volume during normal driving. However, as the fuel injection volume measurement has a margin of error, the value is indicated after correction by input values from the fuel sender gauge assembly.

(2) During refueling:

The fuel level in the fuel tank assembly rises rapidly when fuel is added. If the averaging process that is used during normal driving is used in this case, the fuel receiver gauge reading cannot be updated promptly. Therefore, when it is judged that fuel is being added to the vehicle based on the shift lever position and changes in the fuel level, output values from the fuel sender gauge assembly are immediately reflected in the fuel receiver gauge reading. This control is called refueling judgment.

(c) REFUELING JUDGMENT CONDITIONS

NOTICE:

Add fuel with the ignition switch off to ensure safety and to enable refueling judgment so that an appropriate fuel receiver gauge reading is obtained. If it is necessary to add fuel with the ignition switch ON, stop the vehicle.

(1) Normal judgment condition (When normal refueling method is used)

With the ignition switch off, the fuel sender gauge assembly detect a change of 5.0 liters (5.3 US qts, 4.4 Imp. qts) or more in the fuel level.

(2) Other judgment conditions (When other refueling method is used)

Any of the following conditions is met:

(d) PRECAUTION FOR REFUELING

The fuel sender gauge assembly cannot detect changes in the fuel level within certain ranges (around points E and F). Therefore, even if 5.0 liters (5.3 US qts, 4.4 Imp. qts) or more of fuel is added, refueling judgment may not be performed and the fuel receiver gauge reading may not change when fuel level is within such ranges.

(e) FORCED RESET OF FUEL RECEIVER GAUGE

When driving at 1.8 km/h (1 mph) or more, if the output values from the fuel sender gauge assembly are different from the fuel receiver gauge reading by 15.0 liters (15.9 US qts, 13.2 Imp. qts) or more for approximately 2 minutes, output values from both gauge assemblies are immediately reflected in the fuel receiver gauge reading to compensate for a situation when refueling judgment cannot be made.

PRECAUTION WHEN REPLACING COMBINATION METER ASSEMBLY

(a) When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.

IGNITION SWITCH EXPRESSION

HINT:

The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section.

TIRE PRESSURE WARNING ECU AND RECEIVER EXPRESSIONS

HINT:

The type of tire pressure warning ECU and receiver used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section.