V08423 Knock Sensor 1
GRECM
KNK
E1 12
E6
WIRING DIAGRAM
Wiring Diagram
This shows a wiring diagram of the circuit.
Use this diagram together with ELECTRICAL
WIRING DIAGRAM to thoroughly understand the
circuit.
Wire colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
O = Orange, W = White, GR = Gray, P = Pink,
Y = Yellow, SB = Sky Blue
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe.
DTC P0325Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric element which
generates a voltage when it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If engine
knocking occurs, ignition timing is retarded to suppress it.
DTC No. DTC Detecting Condition Trouble Area
P0325No knock sensor 1 signal to ECM with engine speed,
1,200 rpm or more. Open or short in knock sensor1 circuit
Knock sensor 1 (looseness)
ECM
If the ECM detects the above diagnosis conditions, it operates the fall safe function in which the corrective retard angle
value is set to the maximum value.
Diagnostic Trouble Code No. and Detection Item
Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained.
Indicates the diagnostic trouble code, diagnostic
trouble code set parameter and suspect area of
the problem.
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±33
33 Author: Date:
2005 SEQUOIA (RM1146U)
6. CIRCUIT INSPECTION
How to read and use each page is shown below.
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±757
951 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1751/51 Continuous Electric Current To Height Con-
trol Compressor
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1751/51*1With the AIR SUS relay activated, the vehicle does not go up
to the standard vehicle height after the 90 sec. have elapsed.
Height control compressor assy
Height control compressor circuit
Height control sensor circuit
Height control sensor sub±assy
Relief valve
AIR SUS relay circuit
Air leakage from the air tube or each valve
Clogging in the air tube or each valve
Suspension control ECU
*1: The compressor motor operates continuously to raise vehicle height and allows electric current flow to
the AIR SUS relay for 90 seconds or more under the following conditions:
Vehicle height control is attempted on a steep slope when the vehicle is overloaded.
The compressor remains on for an excessive period of time or repeatedly turns on and off because
of continuous height control switch operation.
If the compressor remains on because the vehicle is jacked up, the vehicle height is set at a position
lower than normal while the engine is running and then the vehicle height control function raises the
vehicle.
Thus DTC C1751/51 may be output and vehicle height control may be suspended. (This is not electrically
abnormal.) In this case, however, the vehicle height operation is resumed approx. 10 min. after the ignition
switch is turned ON after the ECU detects the first error. If ECU detects another error, it takes 70 minutes
until control is resumed.
WIRING DIAGRAM
See page DI±752.
DIDDV±01
