DTC P0320 [MZI-3.7]


id0102d2820300

DTC P0320

Ignition/distributor engine speed input circuit

DETECTION CONDITION
•  The ignition engine speed sensor input signal to the PCM is continuously monitored.
•  The test fails when the signal indicates that 2 successive erratic PIP pulses occurred.
POSSIBLE CAUSE
•  Damaged CKP sensor and/or external trigger wheel
•  Loose wires/connectors.
•  Arcing secondary ignition components (coil, wires or plugs)
•  On-board transmitter (2-way radio)
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
VERIFY RELATED PENDING CODE OR STORED DTCs
•  Turn the ignition switch off then to the ON position (Engine off).
•  Verify related pending code or stored DTCs.
•  Are other DTCs present?
Yes
Go to the appropriate DTC troubleshooting.
No
Go to the next step.
4
INSPECT CKP SENSOR SIGNAL SENT TO PCM
Note
•  The battery should be fully charged and the starting system should be functioning properly.
•  Disable the inertia switch.
•  Turn the ignition switch to the ON position (Engine off)
•  Access the PCM and monitor the RPM PID.
•  Crank the engine.
•  Is the engine speed more than 150 rpm?
Yes
Go to Step 13.
No
Go to the next step.
5
INSPECT TIMING COVER, CKP SENSOR AND EXTERNAL TRIGGER WHEEL (OUTSIDE TIMING COVER) FOR OBVIOUS PHYSICAL DAMAGE
•  Visually check the timing cover, CKP sensor and external trigger wheel (outside the timing cover) for obvious physical damage.
•  Do any parts appear physically damaged?
Yes
Repair if necessary. Then go to Step 13.
No
Go to Step.
6
INSPECT FOR PROPER CKP BIAS VOLTAGES IN PCM
•  Disconnect the CKP sensor connector.
•  Turn the ignition switch to the ON position (Engine off)
•  Measure the voltage between:
―  CKP sensor terminal A on the wiring harness side and battery negative
―  CKP sensor terminal B on the wiring harness side and battery negative
•  Are the voltages between 1—3 V?
Yes
Go to the next step.
No
Go to Step 8.
7
INSPECT CKP SENSOR
•  Inspect the CKP sensor.
•  Is there any malfunction?
Yes
Replace the CKP sensor. Then go to Step 13.
No
Go to the next step.
8
INSPECT CKP WIRING HARNESS SHIELD CIRCUIT FOR SHORT TO GROUND
Note
•  The wiring harness shield protects the CKP signal from electrical noise and is grounded at one end, typically near the PCM.
Note
•  Perform the following resistance measurement between the CKP shield and the ground.
•  Measure the resistance between:
―  CKP_SHLD assembly connector wiring harness side and ground
•  Is the resistance less than 5 ohms?
Yes
Go to the next step.
No
Repair the short circuit. Check for a poor ground. Then go to Step 13.
9
INSPECT FOR SHORT BETWEEN CKP (+) AND CKP (-) IN WIRING HARNESS
•  Turn the ignition switch off.
•  Disconnect the PCM connector.
•  Measure the resistance between:
―  CKP sensor terminal A and B on the wiring harness side
•  Is the resistance more than 10 kilohms?
Yes
Go to the next step.
No
Repair or replace suspected part, then go to Step 13.
10
INSPECT CKP CIRCUIT(S) FOR OPEN CIRCUIT IN WIRING HARNESS
•  Measure the resistance between:
―  CKP sensor connector A on the wiring harness side and PCM terminal 2P
―  CKP sensor connector B on the wiring harness side and PCM terminal 2T
•  Are the resistances less than 5 ohms?
Yes
Go to the next step.
No
Repair or replace suspected part, then go to Step 13.
11
INSPECT CKP CIRCUIT(S) FOR SHORT TO GROUND IN WIRING HARNESS
•  Measure the resistance between:
―  CKP sensor connector A on the wiring harness side and battery negative
―  CKP sensor connector B on the wiring harness side and battery negative
•  Are the resistances more than 10 kilohms?
Yes
Go to the next step.
No
Repair or replace suspected part, then go to Step 13.
12
INSPECT CKP CIRCUIT FOR SHORT TO VOLTAGE IN WIRING HARNESS
•  Turn the ignition switch to the ON position (Engine off)
•  Measure the voltage between:
―  CKP sensor connector A on the wiring harness side and battery negative
―  CKP sensor connector B on the wiring harness side and battery negative
•  Are any voltage present?
Yes
Repair or replace suspected part, then go to the next step.
No
Go to the next step.
13
VERIFY TROUBLESHOOTING OF DTC P0320 HAS BEEN COMPLETED
•  Verify that all disconnected connectors are reconnected.
•  Turn the ignition switch to the ON position (Engine off).
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine and run it at idle.
•  Retrieve DTCs using the M-MDS.
•  Is the PENDING CODE for this DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
14
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.