Suzuki GSX-R 1000 Service Manual: DTC “c46” (p1657-h/l or p1658): excv actuator circuit malfunction

Detected condition

Possible cause

Excva position sensor voltage low or high 0.14 V ≤ Sensor voltage < 4.9 V (without the above range) excva can not operate properly.

• Excva maladjusted.
•  Excva circuit open or short.
•  Excva motor malfunction.
•  Excva position sensor malfunction.
• Excva position sensor circuit shorted to vcc or ground circuit open.
•  Excva position sensor circuit open or shorted to ground or vcc circuit open.
•  Excva motor circuit open or short.
•  Excva motor malfunction.

Excva can not operate properly.

when using the multi-circuit tester, do not strongly touch the terminal of the ecm coupler with a needle pointed tester probe to prevent terminal damage.

after repairing the trouble, clear the dtc using sds tool. Refer to “use of sds diagnosis reset procedures” .

Step

Action

Yes

No

1

1. Turn the ignition switch off.
2.  Remove the left side cowling. Refer to “exterior parts removal and installation” in section 9d .
3.  Check the excva coupler (1) for loose or poor contacts.

4. Turn the ignition switch on.
5.  Check the operation of the excva.

   (Excva operation order: full close → full open → approx. 80% Open)

Is the operation ok?

Step

Action

Yes

No

1

1. Turn the ignition switch off.
2.  Remove the left side cowling. Refer to “exterior parts removal and installation” in section 9d .
3.  Check the excva coupler (1) for loose or poor contacts.

   If ok, then check the excva position sensor lead wire continuity.

4. Disconnect the excva coupler.
5.  Check the continuity between r wire and y wire.

   If the sound is not heard from the tester, the circuit condition is ok.

Special tool
(a): 09900–25008 (multi
circuit tester set)

Tester knob indication continuity ( )

6. Disconnect the ecm couplers.
7.  Check the continuity between y wire and terminal “14”.
8. Also, check the continuity between b/br wire and terminal “35”.

Special tool
(a): 09900–25008 (multi
circuit tester set)
(b): 09900–25009
(needle-point probe set)

Tester knob indication continuity ( )

Excva lead wire continuity continuity ( )

Ecm couplers (harness side)

Is the continuity ok?

Step

Action

Yes

No

1

1. Turn the ignition switch off.
2.  Remove the left side cowling. Refer to “exterior parts removal and installation” in section 9d .
3.  Check the excva coupler (1) for loose or poor contacts.

   If ok, then check the excva position sensor lead wire continuity.

4. Disconnect the excva coupler.
5.  Check the continuity between y wire and ground.
6.  Also, check the continuity between y wire and b/br wire.

   If the sound is not heard from the tester, the circuit condition is ok.

Special tool
(a): 09900–25008 (multi
circuit tester set)

Tester knob indication voltage ( )

7. Disconnect the ecm coupler.
8. Check the continuity between y wire and terminal “14”.
9. Also, check the continuity between r wire and terminal “7”.

Special tool
(a): 09900–25008 (multi
circuit tester set)
(b): 09900–25009
(needle-point probe set)

Tester knob indication continuity ( )

Excva lead wire continuity continuity ( )

Ecm couplers (harness side)

Is the continuity ok?

Step

Action

Yes

No

1

1. Turn the ignition switch off.
2.  Remove the left side cowling. Refer to “exterior parts removal and installation” in section 9d .
3.  Check the excva coupler (1) for loose or poor contacts.

Is the connection ok?

2

1. Turn the ignition switch off.
2.  Check the installation of excv cables. If it is necessary, adjust the excv cables. Refer to “excv cable removal and installation” in section 1k .

3. Disconnect the excva coupler (1).

4. Turn the ignition switch on.
5.  Measure the voltage between the r wire and ground.
6.  If ok, then measure the voltage between the r wire and b/br wire.

Special tool
(a): 09900–25008 (multi
circuit tester set)

Tester knob indication voltage ( )

Excva position sensor input voltage 4.5 – 5.5 V ((+) terminal: r – (–) terminal: ground) ((+) terminal: r – (–) terminal: b/br)

Is the voltage ok?

• Loose or poor contacts on the ecm coupler (terminal “7” or “35”).
•  Open or short circuit in the r or b/br wire.

3

1. Turn the ignition switch off.
2.  Check the continuity between y wire and ground.

Special tool
(a): 09900–25008 (multi
circuit tester set)

Excva position sensor continuity ∞Ω¶ (infinity)

3. If ok, then measure the excva position sensor resistance.
4.  Connect the excva coupler and set the excva to adjustment position. Refer to “excv cable removal and installation” in section 1k .
5.  Disconnect the excva coupler and measure the resistance between y and w wires.

Special tool
(a): 09900–25008 (multi circuit tester set)

Tester knob indication resistance (Ω)

Excva position sensor resistance at adjustment position approx. 3.1 KΩ ((+) y – (–) w)

Is the resistance ok?

4

1. Turn the ignition switch off.
2.  Connect the excva coupler.
3.  Set up the sds tools. Refer to “self-diagnostic procedures” .
4.  Turn the ignition switch on.
5.  Click “exhaust valve operating control” (1).

6. Click “full closed” (2).

7. Insert the needle pointed probes into the back side of the excva coupler (3). ((+) Y – (–) w)
8.  measure the excva position sensor output voltage at excv fully closed position.

Special tool
(a): 09900–25008 (multi
circuit tester set)
(b): 09900–25009
(needle-point probe set)

Tester knob indication voltage ( )

Excva position sensor output voltage excv is fully closed: 0.45 – 1.4 V ((+) y – (–) w)

9. Click “full opened” (4).

10. Measure the excva position sensor output voltage at excv fully opened position.

Special tool
(a): 09900–25008 (multi
circuit tester set)
(b): 09900–25009
(needle-point probe set)

Excva position sensor output voltage excv is fully opened: 3.6 – 4.55 V ((+) y – (–) w)

Is the voltage ok?

5

1. If the excva position sensor output voltage is 0.45 V and less at excv fully closed position, adjust the output voltage to the specified value by turning the no. 1 Cable adjuster (1). Refer to “excv cable removal and installation” in section 1k .
2.  Repeat the procedure in step 4 until the output voltage is set within the specified value. (If c46/p1657 code is indicated after adjusting the voltage, increase the voltage to 0.9 V).

3. If the excva position sensor output voltage is 4.55 V and more at excv fully opened position, adjust the output voltage to the specified value by turning the no. 2 Cable adjuster (2). Refer to “excv cable removal and installation” in section 1k . Repeat the procedure in step 4 until the output voltage is set within the specified value.

Excva position sensor output voltage excv is fully closed: 0.45 ≤ Output voltage ≤  1.4 Excv is fully opened: 3.6 ≤ Output voltage ≤ 4.55

Is the voltage ok?

6

1. Turn the ignition switch off.
2.  Disconnect the excva coupler (1).

3. Apply 12 v to the terminals and check the operation of excva.

4. Then, switch the wires supplied 12 v and check the operation of excva. (Check the operation of excva in both way.)

Is the operation ok?

• Loose or poor contacts on the excva or ecm coupler (terminal “13” or “1”).
•  Open or short circuit in the b/r wire or r/b wire.
•  If wire and connection are ok, intermittent trouble or faulty ecm.
•  Recheck each terminal and wire harness for open circuit and poor connection.
•  Replace the ecm with a known good one, and inspect it again.

• Replace the excva with a new one.
•  Inspect that the excv and two cables move smoothly.