DTC P0568 Cruise Control Set Signal (4JJ3 with DPD)

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(4JJ3 with DPD) Diagnostic system check-engine controls".

2. Current DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to Cruise control set switch operation signal input check.

No

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(4JJ3 with DPD) intermittent conditions of engine".

=>Go to Repair verification.

3. Cruise control set switch operation signal input check

1) Turn OFF the ignition switch.

2) Disconnect the cruise control steering wheel switch harness connector (B34).

3) Connect a fused jumper wire between the signal circuit and the low reference circuit of the cruise control switch (pins 1 and 12 of B34).

4) Turn ON the ignition switch.

5) Observe the Cruise Set/Coast Switch parameter on the scan tool. Does the scan tool display ON when the circuits are connected with a jumper wire, and display OFF when the circuits are not connected?

Yes

Replace the cruise control steering wheel switch.

Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment cruise control steering wheel switch removal".

Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment cruise control steering wheel switch installation".

=>Go to Repair verification.

No

=>Go to Inspection for short to ground in cruise control switch signal circuit.

4. Inspection for short to ground in cruise control switch signal circuit

1) Inspect the cruise control switch signal circuit between the ECM (pin 30 of C10) and the cruise control steering wheel switch (pin 12 of B34) for the following. Is the result normal?

Yes

=>Go to ECM harness connector inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

5. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pin 17 of C9, and pin 30 of C10). Is the connection status normal?

Yes

=>Go to ECM replacement.

No

Repair the connections as necessary.

=>Go to Repair verification.

6. ECM replacement

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM setting".

Procedure completion

=>Go to Repair verification.

7. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Turn ON the ignition switch.

4) While observing the Cruise Set/Coast Switch parameter on the scan tool, operate the switch. Is ON displayed when the switch is operated and OFF when it is released?

Yes

Observe the DTC information with a scan tool.

No

=>Go to Cruise control set switch operation signal input check.