Nissan Maxima Service and Repair Manual: Automatic speed control device (ASCD)

System Diagram

System Description

INPUT/OUTPUT SIGNAL CHART

*: This signal is sent to the ECM via the CAN communication line

BASIC ASCD SYSTEM

Refer to Owner's Manual for ASCD operating instructions.

Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/ h (25 MPH) and 144 km/h (89 MPH).

ECM controls throttle angle of electric throttle control actuator to regulate engine speed.

Operation status of ASCD is indicated by CRUISE lamp in combination meter. If any malfunction occurs in the ASCD system, it automatically deactivates control.

NOTE: Always drive vehicle in a safe manner according to traffic conditions and obey all traffic laws.

SET OPERATION

Press MAIN switch. (The CRUISE lamp in combination meter illuminates.)

When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89 MPH), press SET/COAST switch.

ACCELERATE OPERATION

If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until the switch is released or vehicle speed reaches maximum speed controlled by the system.

And then ASCD will maintain the new set speed.

CANCEL OPERATION

When any of following conditions exist, cruise operation will be canceled.

• CANCEL switch is pressed
• More than 2 switches on ASCD steering switch are pressed at the same time (Set speed will be cleared)
• Brake pedal is depressed
• Selector lever position is N, P or R
• Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
• TCS system is operated
• CVT control system has a malfunction. Refer to EC-437, "Description".

When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform the driver by blinking indicator lamp.

• Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may blink slowly.

When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/ ACCELERATE switch.If MAIN switch is turned to OFF while ASCD is activated, all of ASCD operations will be canceled and vehicle speed memory will be erased.

COAST OPERATION

When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the switch is released. And then ASCD will maintain the new set speed.

RESUME OPERATION

When the RESUME/ACCELERATE switch is pressed after canceling operation other than pressing the MAIN switch, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must meet following conditions.

• Brake pedal is released
• Selector lever position is other than P and N
• Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)

Component Parts Location

1. Intake valve timing control solenoid valve (bank 1)
2. Electronic controlled engine mount control solenoid valve
3. Exhaust valve timing control magnet retarder (bank 2)
4. Intake valve timing control solenoid valve (bank 2)
5. Knock sensor (bank 1 and 2)
6. Fuel injector (bank 2)
7. Ignition coil (with power transistor) and spark plug (bank 2)
8. Exhaust valve timing control position sensor (bank 2)
9. Crankshaft position sensor (POS)
10. Engine coolant temperature sensor
11. Camshaft position sensor (PHASE) (bank 2)
12. Transmission range switch
13. Refrigerant pressure sensor
14. ECM
15. Battery current sensor
16. Condenser-2
17. EVAP canister purge volume control solenoid valve
18. Mass air flow sensor (with intake air temperature sensor)
19. Camshaft position sensor (PHASE) (bank 1)
20. EVAP service port
21. Power valve actuator 2
22. Electric throttle control actuator
23. Exhaust valve timing control position sensor (bank 1)
24. Ignition coil (with power transistor) and spark plug (bank 1)
25. Fuel injector (bank 1)
26. VIAS control solenoid valve 1 and 2
27. Power valve actuator 1
28. Exhaust valve timing control magnet retarder (bank 1)
29. Power steering pressure sensor

1. Mas air flow sensor (with intake air temperature sensor)
2. Air cleaner case
3. Engine coolant temperature sensor (view with engine cover removed)
4. EVAP canister purge volume control solenoid valve (view with engine cover removed)
5. Power valve actuator 1 (view with engine cover removed)
6. VIAS control solenoid valve 1
7. VIAS control solenoid valve 2
8. Power valve actuator 2
9. Power steering pressure sensor
10. Tie rod (RH)
11. Camshaft position sensor (PHASE) (bank 1) (view with air cleaner case removed)
12. Exhaust valve timing control position sensor (bank 1)
13. Camshaft position sensor (PHASE) (bank 2) (view with air cleaner case removed)
14. Exhaust valve timing control position sensor (bank 2)
15. . Engine oil temperature sensor
    : Vehicle front

1. A/F sensor 1 (bank 1) (view with engine removed)
2. A/F sensor 1 (bank 2)
3. HO2S2 (bank 1) harness connector (view with engine removed)
4. HO2S2 (bank 2) harness connector
5. Front engine mount
6. Crankshaft position sensor (POS)
   : Vehicle front

1. Electronic controlled engine mount control solenoid valve (view with engine cover removed)
2. EVAP control system pressure sensor (view with rear suspension member removed)
3. EVAP canister vent control valve
4. EVAP canister
5. Fuel injector harness connector (view with intake manifold collector removed)
6. Exhaust valve timing control magnet retarder (bank 1) (view with engine removed)
7. Intake valve timing control solenoid valve (bank 1)
8. Intake valve timing control solenoid valve (bank 2)
9. Exhaust valve timing control magnet retarder (bank 2)
   : Vehicle front

1. Knock sensor (bank 2) (view with intake manifold removed)
2. Knock sensor (bank 1)
3. Transmission range switch (view with CVT removed)
4. Battery
5. IPDM E/R
6. ECM
7. Refrigerant pressure sensor (view with front grille removed)
8. Accelerator pedal position sensor
   : Vehicle front

1. Stop lamp switch
2. ASCD brake switch
3. ASCD steering switch

Component Description

Component Reference

• ASCD steering switch EC-426, "Description"
• ASCD brake switch EC-429, "Description"
• ASCD clutch switch EC-429, "Description"
• Stop lamp switch EC-448, "Description"
• Electric throttle control actuator EC-465, "Description"
• ASCD indicator