Suzuki GSX-R 1000 Service Manual: DTC “c22” (p1450-h/l): ap sensor circuit malfunction

Detected condition

Possible cause

0.5 V ≤ Sensor voltage < 4.85 V

• Clogged vacuum passage with dust.
•  Ap sensor circuit open or shorted to ground.
•  Ap sensor malfunction.
•  Ecm malfunction.
• Ap sensor circuit is open or shorted to vcc or ground circuit open.
• Ap sensor circuit is shorted to ground or vcc circuit open.

L

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 front seat. Refer to “exterior parts removal and installation” in section 9d .
3.  Remove the starter relay from the bracket.
4.  Check the ap sensor coupler (1) for loose or poor contacts.

   If ok, then measure the ap sensor input voltage.

5. Disconnect the ap sensor coupler.
6.  Turn the ignition switch on.
7.  Measure the input voltage between the r wire and ground.

   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 ( )

Ap 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 couplers.
•  Open or short circuit in the r or b/br wire.

Step

Action

Yes

No

1

1. Turn the ignition switch off.
2.  Remove the front seat. Refer to “exterior parts removal and installation” in section 9d .
3.  Remove the starter relay from the bracket.
4. Check the ap sensor coupler (1) for loose or poor contacts.

   If ok, then check the ap sensor lead wire continuity.

5. Disconnect the ap sensor coupler.
6.  Check the continuity between the r wire and g/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 ( )

7. Disconnect the ecm couplers. Refer to “ecm removal and installation” in section 1c .
8.  Insert the needle pointed probes to the lead wire coupler.
9. Check the continuity between the g/y wire and terminal “20”.

   If ok, then check the continuity between the 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 test ( )

Ecm coupler (harness side)

Is the continuity ok?

Step

Action

Yes

No

1

1. Turn the ignition switch off.
2.  Remove the front seat. Refer to “exterior parts removal and installation” in section 9d .
3.  Remove the starter relay from the bracket.
4. Check the ap sensor coupler (1) for loose or poor contacts.

   If ok, then check the ap sensor lead wire continuity.

5. Disconnect the ap sensor coupler.
6. Check the continuity between the g/y wire and ground.

   Also, check the continuity between the g/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 continuity ( )

7. Disconnect the ecm couplers. Refer to “ecm removal and installation” in section 1c .
8.  Insert the needle pointed probes to the lead wire coupler
9. Check the continuity between the r wire and terminal “7”. Also, check the continuity between the g/y wire and terminal “20”.

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

Tester knob indication continuity ( )

Ecm coupler (harness side)

Is the continuity ok?

2

1. Connect the ecm couplers.
2.  Turn the ignition switch on.
3.  Measure the input voltage between the r wire and ground.

   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 ( )

Ap 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 couplers.
•  Open or short circuit in the r or b/br wire.

3

1. Turn the ignition switch off.
2.  Connect the ecm couplers and ap sensor coupler.
3.  Insert the needle pointed probes to the lead wire coupler.
4.  Run the engine at idle speed and measure the ap sensor output voltage between the g/y wire and b/br wire.

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

Tester knob indication voltage ( )

Ap sensor output voltage approx. 3.6 V at 100 kpa (760 mmhg) ((+) terminal: g/y – (–) terminal: b/br)

Is the voltage ok?

• Check the vacuum port for crack or damage.
•  Open or short circuit in the g/y wire.
•  If vacuum hose and lead wire are ok, replace the ap sensor with a new one. Refer to “ap sensor removal and installation” in section 1c .

4

1. Turn the ignition switch off.
2.  Remove the ap sensor. Refer to “ap sensor removal and installation” in section 1c .
3.  Connect the vacuum pump gauge to the vacuum port of the ap sensor.
4.  Arrange 3 new 1.5 V batteries in series (1) (check that total voltage is 4.5 – 5.0 V) and connect (–) terminal to the ground terminal “b” and (+) terminal to the vcc terminal “a”.
5.  Check the voltage between vout terminal “c” and ground. Also, check if voltage reduces when vacuum is applied up to 53 kpa (400 mmhg) by using vacuum pump gauge.

Special tool
(a): 09917–47011 (vacuum
pump gauge set)
(b): 09900–25008 (multi
circuit tester set)

Tester knob indication voltage ( )

Is the voltage ok?

• G/y, r or b/br wire open or shorted to ground, or poor “7”, “20” or “35” connection.
•  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. Refer to “ecm removal and installation” in section 1c .