Test Dg: Knock Sensor: Testing

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION table of fault code setting condition.

FAULT CODE SETTING CONDITION

Fault Code	KOER	Continuous Memory
P0325	DG1	DG1
P0326	DG1	DG1
P0327	DG1	DG1
P0328	DG1	DG1

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

1) KOER & Continuous Memory DTCs P0325, P0326 (KS1), Or P0330 & P0331 (KS2): Check Voltage On Knock Sensor PID
DTCs P0325, P0326, P0330 and P0331 indicate spark knock voltage exceeded maximum calibrated limit. DTC P0325 and P0326 are for knock sensor No. 1 (cylinder bank that includes cylinder No. 1). DTCs P0330 and P0331 are for knock sensor No. 2. Possible causes for these faults are.
- Open In KS Circuit
- KS Circuit Shorted To PWR Or GND
- Faulty Knock Sensor
- Faulty Powertrain Control Module (PCM)
Turn ignition switch to OFF position. Ensure knock sensor is connected. Perform DRIVE CYCLE PROCEDURE under DIAGNOSTIC MONITORS. Ensure COMPREHENSIVE COMPONENT MONITOR is performed. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, access KS PID from PID/DATA MONITOR & RECORD menu. If PID voltage is less than 3 AC volts, go to next step. If PID voltage is 3 AC volts or more, go to step 6).

2) Check KS Circuit For Intermittent Fault

Using a DVOM, observe voltage while wiggling small sections of wiring harness starting at the knock sensor and working toward PCM. Lightly tap on PCM and KS connectors if possible. A fault will be indicated by a sudden change in voltage. If fault is indicated, isolate fault and repair as necessary. If no fault is indicated, go to next step.

3) Check Knock Sensor Resistance

Turn ignition switch to OFF position. Disconnect KS connector. Using a DVOM, measure resistance between appropriate KS connector terminals. If resistance is 4.39-5.35 megohms, go to step 7). If resistance is more than 5.35 megohms, go to next step. If resistance is 4.39 megohms or less, go to step 5).

4) Check For Open KS Circuit

Disconnect PCM connector(s). Using a DVOM, measure resistance of KS (+) and KS (-) circuits between PCM harness connector and knock sensor harness connector. See KNOCK SENSOR CIRCUIT PCM TERMINAL IDENTIFICATION table. If all resistance measurements are less than 5 ohms, replace knock sensor. If any resistance measurement is 5 ohms or more, repair open in affected circuit.

KNOCK SENSOR CIRCUIT PCM TERMINAL IDENTIFICATION

Application	PCM KS (-) Terminal No.	PCM KS (+) Terminal No.
Continental & Mustang 4.6L (4V)
Bank 1	32	57
Bank 2	23	102
Cougar & Escape 2.0L	87	57
Escort	91	57
Explorer/Mountaineer & LS V8
Bank 1	C42	C51
Bank 2	C43	C52
Focus	87	57
LS V6	C42	C51
All Others	32	57

5) Check KS Circuits For Short To Ground In Harness

Ensure ignition switch is turned to OFF position. Using a DVOM, measure resistance between chassis ground and KS (+) and KS (-) circuits at KS harness connector. If resistance is 10 k/ohms or less, repair short to ground in affected circuit. If resistance is more than 10 k/ohms, go to next step.

6) Check KS Circuits For Short To Power

Turn ignition switch to OFF position. Disconnect PCM connector(s). Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and KS (+) circuit at PCM harness connector. See KNOCK SENSOR CIRCUIT PCM TERMINAL IDENTIFICATION table. If voltage is less than .5 volt, replace PCM. If voltage is .5 volt or more, repair short to power.

7) Check Internal PCM Resistance

Disconnect PCM connector(s). Using a DVOM, measure resistance between PCM connector KS (+) and KS (-) terminals. If resistance is more than 10 k/ohms, replace knock sensor. If concern is still present, replace PCM. If resistance is 10 k/ohms or less, replace PCM.