Description
DATA TROUBLE CODE: 55SYSTEM: Knock Sensor Circuit
CIRCUIT DESCRIPTION
Knock sensors are fitted one each to the right and left banks of 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.
DIAGNOSTIC TROUBLE CODE DETECTING CONDITION
- No No. 2 Knock Sensor signal to Engine Control Module for 4 crank revolutions with engine speed between 1,600 rpm and 5,200 rpm.
TROUBLE AREA
- Open or short in No. 2 Knock Sensor circuit.
- No. 2 Knock Sensor (looseness).
- Engine Control Module.
NOTE: If the Engine Control Module detects the above diagnosis conditions, it operates the fail safe function in which the corrective retard angle value is set to the maximum value.
DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern
To simulate Diagnostic Code detecting condition after Diagnostic Code is recorded. To check that the malfunction is corrected when the repair is completed confirming that Diagnostic Code is no longer detected.
Detection Driving Pattern
Malfunction: Open or Short in Knock Sensor,
1. Start the engine and warm up.
2. After the engine is warmed up, let it idle for 3 minutes.
3. With the A/C ON, perform quick racing (5,000 rpm) 3 times. (Rapidly depress the accelerator pedal and suddenly release it.)
NOTE: If the conditions in this test are not strictly followed, detection of the malfunction will not be possible. If a malfunction exists, the malfunction indicator lamp will light up when sudden racing is performed.
Malfunction Indicator Lamp
Normal Mode On
Test Mode N.A.