Description

DATA TROUBLE CODE: 52, 53 and 55

SYSTEM: Knock Sensor Circuit

CIRCUIT DESCRIPTION



Knock sensors are fitted one each to the front and rear of the left side 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
52 - No.1 (front) knock sensor signal not sent to ECM for 4 crank revolutions with engine speed between 2,050 rpm and 5,950 rpm.
53 - Malfunction in ECM knock control function at engine speed between 650 rpm and 5,200 rpm.
55 - No.2 (rear) knock sensor signal not sent to ECM for 4 crank revolutions with engine speed between 2,050 rpm and 5,950 rpm.
NOTE: If the ECM detects the above conditions, it operates the fail safe function in which the corrective retard angle value is set to maximum.

TROUBLE AREA
52 - Open or short in No.1 (front) knock sensor circuit.
- No.1 knock sensor (looseness).
- ECM.

53 - ECM.

55 - Open or short in No.2 (rear) knock sensor circuit.
- No.2 knock sensor (looseness).
- ECM.

DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN



Purpose of the driving pattern
- To simulate diagnostic trouble code detecting condition after code is recorded.
- To check that the malfunction is corrected when the repair is completed confirming that diagnostic trouble code is no longer detected.