Description
Flat type knock sensors (non-resonant type) have structures that can detect vibrations over a wide band of frequencies: between approximately 6 khz and 15 khz.
A knock sensor is fitted onto the engine block to detect engine knocking.
The knock sensor contains a piezoelectric element which generates a voltage when it becomes deformed.
The voltage is generated when the engine block vibrates due to knocking. Any occurrence of engine knocking can be suppressed by delaying the ignition timing.
Hint:
When any of dtcs p0327 and p0328 are set, the ecm enters fail-safe mode. During fail-safe mode, the ignition timing is delayed to its maximum retardation. Fail-safe mode continues until the ignition switch is turned off.
Reference: inspection using an oscilloscope
Monitor description
If the output voltage transmitted by the knock sensor remains low or high for more than 1 second, the ecm interprets this as a malfunction in the sensor circuit, and sets a dtc.
The monitor for dtcs p0327 and p0328 begins to run when 5 seconds have elapsed since the engine was started.
If the malfunction is not repaired successfully, either dtc p0327 or p0328 is set 5 seconds after the engine is next started.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Typical malfunction thresholds
Wiring diagram
Inspection procedure
Hint:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
Standard: the values change.
Hint
Hint:
The knock feedback value change can be confirmed by running the engine at high load, for example, by activating the air conditioning system and revving up the engine.
Standard
Standard voltage
Notice:
Fault may be intermittent. Check the wire harness and connectors carefully and retest.
Standard resistance
Fuel pressure regulator
Components
Removal
Remove fuel tank assembly
Remove the fuel tank (see page fu-39).
Remove fuel tank main tube sub-assembly
Remove the joint clip and fuel tank main tube.
Caution:
Before removing the tube joint clip, check for
foreign matter around the cli ...
Air fuel ratio sensor
Components
On-vehicle inspection
Check air fuel ratio compensation system
Connect the intelligent tester to the dlc3.
Turn the ignition switch on.
Select the following menu items: data list / a/fs b1
s1 and o2s b1 s2.
Warm up the a/f sensor with the engine speed at
2,500 ...
If your vehicle needs to be
towed
If towing is necessary, we
recommend having your
vehicle towed by your
Toyota dealer or commercial
towing service, using a
wheel-lift type truck or flatbed
truck.
Use a safety chain system
for all towing, and abide by
all state/provincial and local
laws.
Situations when it is necessary
to contact d ...