DTC P0571 (Flash Code 26) Brake Switch Circuit (RZ4E-TC)

For the diagnostic type, refer to the diagnostic type list in the DTC description.

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Diagnostic system check-engine controls".

2. Stoplight switch 1 signal check

1) Connect the scan tool.

2) Turn ON the ignition switch.

3) While observing the Brake Pedal Switch 1 parameter on the scan tool, fully depress and release the brake pedal repeatedly. Is Applied displayed when the brake pedal is depressed and Released when it is released?

Yes

=>Go to Stoplight switch 2 signal check.

No

=>Go to Inspection for open circuit in stoplight switch 1 power supply circuit.

3. Inspection for open circuit in stoplight switch 1 power supply circuit

1) Turn OFF the ignition switch.

2) Disconnect the stoplight switch harness connector (C69).

3) Connect a test lamp between the ignition power supply circuit (pin 3 of C69) and the body ground.

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Turn ON the ignition switch. Does the test lamp illuminate?

Yes

=>Go to Stoplight switch 1 signal check using fused jumper wire.

No

Repair the open circuit or high resistance in the stoplight switch 1 ignition power supply circuit between the ENGINE(IG1) 5A fuse and the stoplight switch (pin 3 of C69). Inspect the ENGINE(IG1) 5A fuse first.

=>Go to Repair verification.

4. Stoplight switch 1 signal check using fused jumper wire

1) Turn ON the ignition switch.

2) Observe the Brake Pedal Switch 1 parameter on the scan tool while momentarily connecting a fused jumper wire to the stoplight switch 1 circuit (pins 3 and 4 of C69). Does the scan tool display Applied when the circuits are connected with a jumper wire, and display Released when the circuits are not connected?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Stoplight switch harness connector inspection.

No

=>Go to Inspection for open circuit and short circuit in stoplight switch 1 signal circuit.

5. Inspection for open circuit and short circuit in stoplight switch 1 signal circuit

1) Inspect the stoplight switch 1 signal circuit between the ECM (pin 45 of C7) and the stoplight switch (pin 4 of C69) for the following. Is the result normal?

  • Open circuit
  • Short to ground
  • High resistance

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM harness connector inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

6. Stoplight switch 2 signal check

1) Connect the scan tool.

2) Turn ON the ignition switch.

3) While observing the Brake Pedal Switch 2 parameter on the scan tool, fully depress and release the brake pedal repeatedly. Is Applied displayed when the brake pedal is depressed and Released when it is released?

Yes

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(RZ4E-TC) intermittent conditions of engine".

No

=>Go to Inspection for open circuit in stoplight switch 2 power supply circuit.

7. Inspection for open circuit in stoplight switch 2 power supply circuit

1) Turn OFF the ignition switch.

2) Connect a test lamp between the battery power supply circuit (pin 1 of C69) and the body ground.

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

3) Turn ON the ignition switch. Does the test lamp illuminate?

Yes

=>Go to Stoplight switch 2 signal check using fused jumper wire.

No

Repair the open circuit or high resistance in the stoplight switch 2 battery power supply circuit between the STOP(+B) 10A fuse and the stoplight switch (pin 1 of C69). Inspect the STOP(+B) 10A fuse first.

=>Go to Repair verification.

8. Stoplight switch 2 signal check using fused jumper wire

1) Turn ON the ignition switch.

2) Observe the Brake Pedal Switch 2 parameter on the scan tool while momentarily connecting a fused jumper wire to the stoplight switch 2 circuit (pins 1 and 2 of C69). Does the scan tool display Released when the circuits are connected with a jumper wire and display Applied when the circuits are not connected?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Stoplight switch harness connector inspection.

No

=>Go to Inspection for open circuit and short circuit in stoplight switch 2 signal circuit.

9. Inspection for open circuit and short circuit in stoplight switch 2 signal circuit

1) Inspect the stoplight switch 2 signal circuit between the ECM (pin 27 of C7) and the stoplight switch (pin 2 of C69) for the following. Is the result normal?

  • Open circuit
  • Short to ground
  • High resistance

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM harness connector inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

10. Stoplight switch harness connector inspection

1) Inspect for poor connections at the stoplight switch harness connector (pins 1, 2, 3, and 4 of C69). Is the connection status normal?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Stoplight switch inspection.

No

Repair the connections as necessary.

=>Go to Repair verification.

11. Stoplight switch inspection

1) Remove the stoplight switch.

Refer to "4.Brakes 4B.Brake System stoplight switch removal".

2) Inspect the stoplight switch. Is the result normal?

Refer to "4.Brakes 4B.Brake System stoplight switch inspection".

Yes

=>Go to ECM harness connector inspection.

No

Replace the stoplight switch.

Refer to "4.Brakes 4B.Brake System stoplight switch removal".

Refer to "4.Brakes 4B.Brake System stoplight switch installation".

=>Go to Repair verification.

12. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pins 27 and 45 of C7). Is the connection status normal?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM replacement.

No

Repair the connections as necessary.

=>Go to Repair verification.

13. ECM replacement

Note

  • Perform programming after replacing the ECM.

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM setting".

Procedure completion

=>Go to Repair verification.

14. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool.