Home ReviewsRefund
Home/Lexus/IS/Lexus IS II facelift (2008-2010)/Repair manual/Gauges & Instrument Panels/Meter (Diagnostics): Overview
Contents Wiring diagrams Section: Gauges & Instrument Panels All sections

Meter (Diagnostics): Overview Lexus IS II facelift

Gauges & Instrument Panels 21 illustrations ~2895 words

DESCRIPTION

  1. This circuit is the power source circuit for the meter.
  2. This circuit provides two types of power sources; one is a constant power source mainly used as a backup power source, and the other is a power source mainly used for signal transmission. The constant power source is mainly used as a backup power source of the meter CPU, however, it is also used for communication.
  3. If a voltage of 12 V is not applied to terminal IG+ when the engine switch is on (IG), the indicator will not operate.

Scheme 55

Scheme 55: WIRING DIAGRAM
Scheme 55: WIRING DIAGRAM

Scheme 56

Scheme 56: PROCEDURE
Scheme 56: PROCEDURE
  1. INSPECT COMBINATION METER ASSEMBLY Disconnect the J34 connector. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition J34-1 (E2) - Body ground Always Below 1 ohms J34-13 (ES) - Body ground Always Below 1 ohms Measure the voltage according to the value(s) in the table below. Standard voltage Tester Connection Condition Specified Condition J34-12 (IG+) - Body ground Engine switch on (IG) 10 to 14V J34-23 (B) - Body ground Always 10 to 14 V J34-24 (B) - Body ground Always 10 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE COMBINATION METER ASSEMBLY
  1. The meter CPU receives vehicle speed signals from this circuit.
  2. The vehicle speed sensor detects the voltage that varies according to the vehicle speed.
  3. The skid control ECU supplies power to the vehicle speed sensor.
  4. The skid control ECU detects vehicle speed signals based on the pulses of the voltage.
  5. The skid control ECU transmits vehicle speed signals as pulses to the meter CPU.
  6. The meter CPU calculates the vehicle speed converting 4 pulses to 1 revolution

Scheme 57

Scheme 57: WIRING DIAGRAM
Scheme 57: WIRING DIAGRAM
  1. The meter CPU receives engine speed signals from the ECM in this circuit.
  2. The ECM transmits engine speed signals as pulses to the meter CPU.
  3. The meter CPU calculates the engine speed converting 3 pulses to 1 revolution.

Scheme 58

Scheme 58: WIRING DIAGRAM
Scheme 58: WIRING DIAGRAM

Scheme 59

Scheme 59: PROCEDURE
Scheme 59: PROCEDURE

Scheme 60

Scheme 60
Scheme 60

Scheme 61

Scheme 61
Scheme 61
  1. PERFORM ACTIVE TEST USING TECHSTREAM (TACHO METER OPERATION) Connect Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester ON. Enter the following menus: Body Electrical / Combination Meter / Active Test. Check the operation by referring to the values in the table below. COMBINATION METER: Tester Display Test Part Control Range Diagnostic Note Tacho Meter Operation Tachometer 0, 1000, 2000, 3000, 4000, 5000, 6000, 7000 (rpm) - OK Needle indication is normal. NG --> REPLACE COMBINATION METER ASSEMBLY OK: Go to next step
  2. READ VALUE USING TECHSTREAM (ENGINE RPM) Connect Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester ON. Enter the following menus: Body Electrical / Combination Meter / Data List. Check the values by referring to the values in the table below. COMBINATION METER: Tester Display Measurement Item/Range Normal Condition Diagnostic Note Engine Rpm Engine speed/Min.: 0 rpm, Max.: 12750 rpm Almost same as actual engine speed (When engine is running) If data received from the ECM exceeds the range that can be displayed on the meter, the meter continues to display the maximum value of the range. OK Engine speed displayed on the tester is almost the same as the actual engine speed. NG --> See step 3 OK --> REPLACE COMBINATION METER ASSEMBLY
  3. READ VALUE USING TECHSTREAM (ENGINE SPEED) Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester ON. Enter the following menus: Powertrain / Engine and ECT / Data List. Check the values by referring to the table below. ENGINE AND ECT: Tester Display Measurement Item/Range Normal Condition Diagnostic Note Engine Speed Engine speed/Min.: 0 rpm, Max.: 16383.75 rpm Almost same as actual engine speed (When engine is running) - OK Engine speed displayed on the tester is almost the same as the actual engine speed. NG --> GO TO SFI SYSTEM OK: Go to next step
  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) Disconnect the A6 and J34 connectors. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition A6-16 (TACH) - J34-16 (S) Always Below 1 ohms A6-16 (TACH) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  5. INSPECT COMBINATION METER ASSEMBLY Check the input signal waveform. Disconnect the J34 connector. Reconnect the A6 connector. Connect the oscilloscope to the terminal J34-16 (S) and body ground. Start the engine. Check the signal waveform according to the condition(s) in the table below. Item Condition Tool setting 5 V/DIV., 10 ms./DIV. Vehicle condition Engine idle speed OK The waveform is displayed as shown in the illustration. OK --> REPLACE COMBINATION METER ASSEMBLY NG --> REPLACE ECM
  1. The meter CPU receives fuel level signals from this circuit. The fuel sender controls the resistance value in accordance with changes in sender gauge position. The meter CPU detects the fuel level from the transformed voltage. The meter CPU outputs a constant voltage of 12 V to the fuel sender. In the fuel sender, the voltage is changed due to the resistance. The changed voltage is output from the fuel sender to the meter CPU, thus the fuel level is determined by fuel injection signals transmitted using the BEAN lines.

HINT

The fuel level warning light will come on when the fuel level is below 11.0 liters (9.7 US qts, 11.6 lmp qts).

Scheme 62

Scheme 62: WIRING DIAGRAM
Scheme 62: WIRING DIAGRAM

Scheme 63

Scheme 63: PROCEDURE
Scheme 63: PROCEDURE

Scheme 64

Scheme 64
Scheme 64

Scheme 65

Scheme 65
Scheme 65
  1. CHECK CAN COMMUNICATION SYSTEM Check if CAN communication DTC is output. Refer to «DIAGNOSIS SYSTEM»(ref-387391-S05169532582011022400000). RESULT Result Proceed to DTC is not output A DTC is output B B --> REPAIR CIRCUITS INDICATED BY OUTPUT DTCS A: Go to next step
  2. CHECK MULTIPLEX COMMUNICATION SYSTEM Check if MULTIPLEX communication DTC is output. Refer to «DTC CHECK / CLEAR»(ref-387386-S41628963162011022400000). RESULT Result Proceed to DTC is not output A DTC is output B B --> REPAIR CIRCUITS INDICATED BY OUTPUT DTCS A: Go to next step
  3. PERFORM ACTIVE TEST USING TECHSTREAM (FUEL METER OPERATION) Connect Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester ON. Enter following menus: Body Electrical / Combination Meter / Active Test. Check the operation by referring to the table below. COMBINATION METER: Tester Display Test Part Control Range Diagnostic Note Fuel Meter Operation Fuel receiver gauge EMPTY, 1/2, FULL - OK Needle indication is normal. NG --> REPLACE COMBINATION METER ASSEMBLY OK: Go to next step
  4. READ VALUE USING TECHSTREAM (FUEL INPUT) Connect Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester ON. Enter following menus: Body Electrical / Combination Meter / Data List. Check the values by referring to the table below. COMBINATION METER: Tester Display Measurement Item/Range Normal Condition Diagnostic Note Fuel Input Fuel input signal Min.: 0, Max.: 255 Fuel gauge indicates (F): 35 Fuel gauge indicates (1/2): 145 Fuel gauge indicates (E): 205 - OK Fuel value signal displayed on the tester is almost the same as needle indication. NG --> See step 5 OK --> REPLACE COMBINATION METER ASSEMBLY
  5. INSPECT FUEL SENDER GAUGE ASSEMBLY Disconnect the connectors from the fuel sender gauges. Measure the resistance according to the value(s) in the table below. Standard resistance: Fuel sender gauge (Main) Tester Connection Condition Specified Condition Q14-2 (S) - Q14-3 (FE) Always 6.5 to 242.6 ohms Standard resistance: Fuel sender gauge (Sub) Tester Connection Condition Specified Condition P10-1 (FS) - P10-2 (E) Always 6.5 to 171.9 ohms NG --> REPLACE FUEL SENDER GAUGE ASSEMBLY OK: Go to next step
  6. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - FUEL SENDER GAUGE ASSEMBLY) Disconnect the fuel tank wires from the fuel sender gauge assembly. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition J34-19 (FR) - Q14-2 (S) Always Below 1 ohms Q14-3 (FE) - P10-1 (FS) Always Below 1 ohms P10-2 (E) - J34-2 (FE) Always Below 1 ohms Q14-2 (S) - Body ground Always 10 kohms or higher P10-1 (FS) - Body ground Always 10 kohms or higher J34-2 (FE) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  7. INSPECT FUEL SENDER GAUGE ASSEMBLY Disconnect the fuel sender gauge connector. Inspect the fuel sender gauge assembly (main). Remove the fuel sender gauge assembly (main). Check that the float moves smoothly between F and E. Measure the resistance between the terminals 2 (S) and 3 (FE) of connector according to the value(s) in the table below. Standard resistance Main Float Level Resistance (ohms) F 6.5 to 8.5 Between E and F 6.5 to 242.6 (Gradually changes) E 237.6 to 242.6 Inspect the fuel sender gauge assembly (sub). Remove the fuel sender gauge assembly (sub). Check that the float moves smoothly between F and E. Measure the resistance between the terminals 1 (FS) and 2 (E) according to the value(s) in the table below. Standard resistance Sub Float Level Resistance (ohms) F 6.5 to 8.5 Between E and F 6.5 to 171.9 (Gradually changes) E 167.9 to 171.9 NG --> REPLACE FUEL SENDER GAUGE ASSEMBLY OK: Go to next step
  8. REPLACE COMBINATION METER ASSEMBLY Replace the combination meter assembly to a new one or a known normal one. OK The operation of the combination meter assembly returns to normal. NG --> REPLACE ECM OK --> END
  1. In this circuit, the meter CPU receives engine coolant temperature signals from the ECM using the CAN lines.
  2. The meter CPU displays engine coolant temperature that is calculated based on the data received from the ECM.

Scheme 66

Scheme 66: WIRING DIAGRAM
Scheme 66: WIRING DIAGRAM
  1. The meter CPU receives signals for adjusting illumination on the meter and instrument panel from this circuit
  2. The meter CPU detects the illumination level selected by the user according to the position of the rheostat knob.

HINT

  1. This model is equipped with an Optitron meter, therefore the meter illuminates even in the daytime.
  2. The meter illumination level can be adjusted by turning the rheostat.
  3. The meter illumination dims when the light control switch is turned to the TAIL or HEAD position at night.
  4. Turning the rheostat knob fully clockwise cancels the above dimmer control.
  5. During light control switch TAIL/HEAD position, turn the rheostat knob fully counterclockwise, then the meter illumination turns off.

Scheme 67

Scheme 67: WIRING DIAGRAM
Scheme 67: WIRING DIAGRAM

Scheme 68

Scheme 68: PROCEDURE
Scheme 68: PROCEDURE

Scheme 69

Scheme 69
Scheme 69

Scheme 70

Scheme 70
Scheme 70

Scheme 71

Scheme 71
Scheme 71
  1. SYSTEM CHECK Result Result Proceed to Meter illumination does not change when operate the light control rheostat knob A Dimmer cancel does not operate B B --> See step 7 A: Go to next step
  2. READ VALUE USING TECHSTREAM (RHEOSTAT VALUE) Connect Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester ON. Enter the following menus: Body Electrical / Combination Meter / Active Test. Check the values by referring to the table below. COMBINATION METER: Tester Display Measurement Item/Range Normal Condition Diagnostic Note Rheostat value Light control rheostat/Min.: 0%, Max.: 100% Light control rheostat switch is Dark (0%) --> Bright (100%) - OK The value displayed on the tester gradually changes as the actual rheostat operation. NG --> See step 4 OK: Go to next step
  3. READ VALUE USING TECHSTREAM (TAIL CANCEL SW) Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester ON. Enter the following menus: Body Electrical / Combination Meter / Data List. Check the values by referring to the table below. COMBINATION METER: Tester Display Measurement Item/Range Normal Condition Diagnostic Note Tail Cancel SW Tail cancel switch is OFF/ON OFF: Light control rheostat position is except below - ON: Turn the Light control rheostat knob fully upwards - OK Condition displayed on the tester is the same as the actual rheostat position. NG --> See step 7 OK --> REPLACE COMBINATION METER ASSEMBLY
  4. INSPECT LIGHT CONTROL RHEOSTAT Remove the light control rheostat with the connector still connected. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition E (J15-1) - RV (J15-4) Turn the rheostat knob fully clockwise 8 to 12 kohms E (J15-1) - RV (J15-4) Rheostat knob is between MIN. and MAX. The value changes gradually (Between approx. 0 to 8 kohms) E (J15-1) - RV (J15-4) Turn the rheostat knob fully counterclockwise Approx. 0 ohms NG --> REPLACE LIGHT CONTROL RHEOSTAT OK: Go to next step
  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT) Disconnect the J34 and J15 connectors. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition J34-14 (ET) - J15-1 (E) Always Below 1 ohms J34-9 (ILL+) - J15-3 (T) Always Below 1 ohms J34-21 (TR) - J15-4 (RV) Always Below 1 ohms J15-1 (E) - Body ground Always 10 kohms or higher J15-3 (T) - Body ground Always 10 kohms or higher J15-4 (RV) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE COMBINATION METER ASSEMBLY
  6. READ VALUE USING TECHSTREAM (TAIL CANCEL SW) Connect Techstream to the DLC3. Engine switch on (IG). Turn the tester ON. Enter the following menus: Body Electrical / Combination Meter / Data List. Check the values by referring to the table below. COMBINATION METER: Tester Display Measurement Item/Range Normal Condition Diagnostic Note Tail Cancel SW Tail cancel switch is ON/OFF ON: Light control rheostat turns fully clockwise OFF: Light control rheostat position is except above. - OK Rheostat position displayed on the tester is same as the actual rheostat position. NG --> See step 7 OK --> REPLACE COMBINATION METER ASSEMBLY
  7. INSPECT LIGHT CONTROL RHEOSTAT Remove the light control rheostat with connector still connected. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition TC (J15-2) - T (J15-3) Turn the rheostat knob fully counterclockwise Below 1 ohms TC (J15-2) - T (J15-3) Turn the rheostat knob fully clockwise 10 kohms or higher NG --> REPLACE LIGHT CONTROL RHEOSTAT OK: Go to next step
  8. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT) Disconnect the J34 and J15 connectors. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition J34-8 (TC) - J15-2 (TC) Always Below 1 ohms J15-2 (TC) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE COMBINATION METER ASSEMBLY
  1. In this circuit, the meter CPU receives auto dimmer signals from the main body ECU RH using the BEAN lines.
  2. When the meter CPU receives an auto dimmer signal, it dims the meter illumination.
  3. The main body ECU RH determines whether it is daytime, twilight, or nighttime based on the waveform transmitted from the automatic light control sensor.
  4. If the main body ECU RH determines that it is daytime, the ECU does not send auto dimmer signals.
  5. Therefore, the meter illumination (warning and indicator lights) will not dim even if the driver accidentally turns the light control switch to the TAIL or HEAD position in daytime.

Scheme 72

Scheme 72: WIRING DIAGRAM
Scheme 72: WIRING DIAGRAM
  1. In this circuit, the meter CPU receives auto dimmer signals from the main body ECU RH using the BEAN lines.
  1. When the meter CPU receives an auto dimmer signal, it dims the meter illumination.
  1. The main body ECU RH determines whether it is daytime, twilight, or nighttime based on the waveform transmitted from the automatic light control sensor.
  1. If the main body ECU RH determines that it is daytime, the ECU does not send auto dimmer signals.
  1. Therefore, the meter illumination (warning and indicator lights) will not dim even if the driver accidentally turns the light control switch to the TAIL or HEAD position in daytime.
  1. The meter CPU receives satellite switch signals from the satellite switch in this circuit.
  2. The meter CPU sends satellite switch signals to the tire pressure warning ECU, AFS ECU, clearance sonar ECU, driver side mirror ECU and passenger side mirror ECU using the BEAN lines. Each ECU controls every system based on these signals.

Scheme 73

Scheme 73: WIRING DIAGRAM
Scheme 73: WIRING DIAGRAM

Scheme 74

Scheme 74: PROCEDURE
Scheme 74: PROCEDURE

Scheme 75

Scheme 75
Scheme 75
  1. INSPECT SATELLITE SWITCH Disconnect the connector from the satellite switch. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition J16-2 (LSFT) - J16-5 (E) Satellite switch LH is pressed Below 1 ohms J16-2 (LSFT) - J16-5 (E) Satellite switch LH is not pressed 10 kohms or higher J16-3 (SET) - J16-5 (E) Satellite switch ON/OFF is pressed Below 1 ohms J16-3 (SET) - J16-5 (E) Satellite switch ON/OFF is not pressed 10 kohms or higher J16-4 (RSEL) - J16-5 (E) Satellite switch RH is pressed Below 1 ohms J16-4 (RSEL) - J16-5 (E) Satellite switch RH is not pressed Below 1 ohms NG --> REPLACE SATELLITE SWITCH OK: Go to next step
  2. CHECK HARNESS AND CONNECTOR (COMBINATION METER - SATELLITE SWITCH) Disconnect the J35 and J16 connectors. Measure the resistance according to the value(s) in the table below. Standard resistance Tester Connection Condition Specified Condition J35-5 (RSEL) - J16-4 (RSEL) Always Below 1 ohms J35-6 (LSEL) - J16-2 (LSFT) Always Below 1 ohms J35-7 (SET) - J16-3 (SET) Always Below 1 ohms J16-2 (LSFT) - Body ground Always 10 kohms or higher J16-3 (SET) - Body ground Always 10 kohms or higher J16-4 (RSEL) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE COMBINATION METER ASSEMBLY

See also:
• REMOVAL
• REMOVAL

More articles — Meter (Diagnostics)