- With the exhaust valve not activated, an open signal of the exhaust valve is detected for 1 second or more.
- With the exhaust valve activated, a short signal of the exhaust valve is detected 8 times successively.
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Suspension | Section: Suspension Control System | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000001N95003X |
| Title: SUSPENSION CONTROL: AIR SUSPENSION SYSTEM (w/o AVS): DESCRIPTION (2008 Sequoia) | ||
|
DTC |
C1745 |
Exhaust Solenoid Valve Circuit Malfunction |
DESCRIPTION
The suspension control ECU operates the exhaust solenoid valve (No. 1 height control compressor), releases the air from the height control cylinder assembly (pneumatic cylinder), and lowers vehicle height.
When the vehicle height is lowered, the suspension control ECU opens the height control valve and then operates the exhaust solenoid valve to release the compressed air to the outside.
The exhaust solenoid valve is on the compressor unit and has only one valve.
|
DTC Code |
Detection Condition |
Trouble Area |
|---|---|---|
|
C1745 |
When either of the following is detected: |
|
HINT:
- Once the ECU stores DTC C1745 in the memory, the vehicle height control is suspended until a normal signal is input to the ECU from the exhaust solenoid valve. However, control is resumed if the ignition switch is turned off, then to ON again.
-
Malfunction in the exhaust solenoid valve:
The height control indicator light "N" comes on or blinks, and "HI" and "LO" do not come on by operating the height control switch "UP" or "DOWN".
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
-
If DTC C1781 (ECU malfunction) and/or C1782 (power source circuit) is displayed, perform the inspection necessary for DTC C1781
and/or C1782
first.
- If DTC C1781 and the C1782 are output at the same time, perform the inspection necessary for DTC C1782 first.
PROCEDURE
|
1. |
PERFORM ACTIVE TEST USING TECHSTREAM (EXHAUST SOLENOID) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON, and turn the Techstream main switch on.
(c) Enter the following menus: Chassis / Air suspension / Active Test.
Air Suspension
|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Exhaust Solenoid |
Exhaust solenoid valve |
ON or OFF |
Operation sound of solenoid (clicking sound) can be heard |
OK:
Operation of solenoid (clicking sound) can be heard
Result
|
Result |
Proceed to |
|---|---|
|
NG |
A |
|
OK (When troubleshooting according to the Problem Symptoms Table) |
B |
|
OK (When troubleshooting according to the DTC Chart) |
C |
|
|
2. |
INSPECT NO. 1 HEIGHT CONTROL COMPRESSOR (EXHAUST SOLENOID VALVE) |
|
(a) Turn the ignition switch off. |
(b) Disconnect Q3 solenoid valve connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1(B) - 2 (L) |
20°C (68°F) |
10 to 14 Ω |
(d) Connect the battery positive (+) lead to terminal 1 and the negative (-) lead to terminal 2 of the solenoid valve connector. Then check that the valve makes an operating sound.
OK:
Operation of solenoid (clicking sound) can be heard
|
|
3. |
CHECK HARNESS AND CONNECTOR (EXHAUST SOLENOID VALVE - ECU AND BODY GROUND) |
|
(a) Disconnect the O19 ECU connector. |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
Q3-1 (B) - O19-1 (SLEX) |
Always |
Below 1 Ω |
|
Q3-1 (B) or O19-1 (SLEX) - Body ground |
Always |
10 kΩ or higher |
|
Q3-2 (L) - Body ground |
Always |
Below 1 Ω |
|
|
|