DTC 43: KNOCK SENSOR WITHOUT SPARK MODULE (SINGLE SENSOR) Chevrolet Chevy Van G3500

DTC 43: KNOCK SENSOR WITHOUT SPARK MODULE (SINGLE SENSOR)

Note. Test numbers refer to test numbers on diagnostic chart.

1. Code 43 will set when vehicle reaches normal operating temperature (but not overheating), high engine load is indicated by MAP sensor and voltage on sensor signal circuit is greater than 3.5 volts DC or less than 1.5 volts DC. This step determines if system is functioning properly at current time.
2. This step determines state of 5-volt reference signal applied to sensor.
3. Checks knock sensor internal resistance.

Control module applies and monitors a 5-volt DC signal to knock sensor. Internal knock sensor circuitry pulls this DC signal down to about 2.5 volts. When knock sensor detects detonation, it generates an AC signal which rides back on DC signal to control module. Knock signal intensity is dependent upon knock signal level.

Code 43 Schematic (5.7L) Knock Sensor Without Spark Module (Single Sensor). Scheme 357

Code 43 Flow Chart (5.7L) Knock Sensor Without Spark Module (Single Sensor). Scheme 358