Kawasaki Z1000SX - Service manual > Main Throttle Sensor (Service Code 11)

The main throttle sensor is a rotating variable resistor that change output voltage according to throttle operating. The ECU senses this voltage change and determines fuel injection quantity, and ignition timing according to engine rpm, and throttle opening.

Input Terminal [A]
Output Terminal [B]
Ground Terminal [C]

Main Throttle Sensor Removal/Adjustment

NOTICE Do not remove or adjust the main throttle sensor [A] since it has been adjusted and set with precision at the factory.

Never drop the throttle body assy especially on a hard surface. Such a shock to the main throttle sensor can damage it.

Main Throttle Sensor Input Voltage Inspection

NOTE

• Be sure the battery is fully charged.

 

• Turn the ignition switch OFF.
• Remove the right lower fairing (see Lower Fairing Removal in the Frame chapter).
• Disconnect the main throttle sensor connector and connect the harness adapter [A] between these connectors.

  Special Tool - Throttle Sensor Setting Adapter: 57001 -1538

• Connect a digital meter to the harness adapter leads.

Main Throttle Sensor Input Voltage
 Connections to Adapter:
  Digital Meter (+) → W (sensor BL) lead
  Digital Meter (-) → BK (sensor BR/BK) lead

• Measure the input voltage with the engine stopped and with the connector joined.
• Turn the ignition switch ON.

Input Voltage
 Standard: DC 4.75 - 5.25 V

• Turn the ignition switch OFF.

  If the reading is within the standard, check the output voltage (see Main Throttle Sensor Output Voltage Inspection).

  If the reading is out of the standard, remove the ECU and check the wiring for continuity between main harness connectors.

• Disconnect the ECU and sensor connectors.

Wiring Inspection
 ECU Connector [A] ←→
  Main Throttle Sensor Connector [B]
   BL lead (ECU terminal 5) [C]
   BR/BK lead (ECU terminal 33) [D]

If the wiring is good, check the ECU for its ground and power supply (see ECU Power Supply Inspection).

If the ground and power supply are good, replace the ECU (see ECU Removal/Installation).

Main Throttle Sensor Output Voltage Inspection

• Measure the output voltage at the main throttle sensor in the same way as input voltage inspection, note the following.
  • Disconnect the main throttle sensor connector and connect the harness adapter [A] between these connectors.

Special Tool - Throttle Sensor Setting Adapter: 57001-1538

Main Throttle Sensor Output Voltage
 Connections to Adapter:
  Digital Meter (+) → R (sensor BL/W) lead
  Digital Meter (-) → BK (sensor BR/BK) lead

• Start the engine and warm it up thoroughly.
• Check idle speed to ensure the throttle opening is correct.

Idle Speed
 Standard: 1 100 +-50 r/min (rpm)

If the idle speed is out of the specified range, adjust it (see Idle Speed Inspection in the Periodic Maintenance chapter).

• Turn the ignition switch OFF.
• Measure the output voltage with the engine stopped and with the connector joined.
• Turn the ignition switch ON.

Output Voltage
 Standard:
  DC 1.02 - 1.06 V at idle throttle opening
  DC 4.22 - 4.42 V at full throttle opening (for reference)

NOTE

• Open the throttle, confirm the output voltage will be raise.
• The standard voltage refers to the value when the voltage reading at the Input Voltage Inspection shows 5 V exactly.
• When the input voltage reading shows other than 5 V, derive a voltage range as follows.

  Example:
  In the case of a input voltage of 4.75 V.
  1.02 × 4.75 ÷ 5.00 = 0.969 V
  1.06 × 4.75 ÷ 5.00 = 1.007 V
  Thus, the valid range is 0.969 - 1.007 V

 

• Turn the ignition switch OFF.

  If the reading is out of the standard, check the main throttle sensor resistance (see Main Throttle Sensor Resistance Inspection).

  If the reading is within the standard, remove the ECU and check the wiring for continuity between main harness side connectors.

  • Disconnect the ECU and sensor connectors.

Wiring Inspection
 ECU Connector [A] ←→
  Main Throttle Sensor Connector [B]
   BL/W lead (ECU terminal 26) [C]
   BR/BK lead (ECU terminal 33) [D]

If the wiring is good, check the ECU for its ground and power supply (see ECU Power Supply Inspection).

If the ground and power supply are good, replace the ECU (see ECU Removal/Installation).

Main Throttle Sensor Resistance Inspection

• Turn the ignition switch OFF.
• Disconnect the main throttle sensor connector.
  • Disconnect the main throttle sensor connector and connect the harness adapter [A] to the sensor connector only.

Special Tool - Throttle Sensor Setting Adapter: 57001 -1538

Main Throttle Sensor Resistance
 Connections to Adapter:
  Digital Meter (+) → W (sensor BL) lead
  Digital Meter (-) → BK (sensor BR/BK) lead

Standard: 4 - 6 kΩ

If the reading is out of the standard, replace the throttle body assy.

If the reading is within the standard, but the problem still exists, replace the ECU (see ECU Removal/Installation).

Main Throttle Sensor Circuit

1. ECU
2. Main Throttle Sensor

See also: