P1311

DTC P1311 ION Sensing Module SEC line 1 Circuit Fault




Circuit Description
- The Power Control Module (PCM) will compare the secondary current reading to a predetermined maximum and minimum thresholds.
If the secondary current signal pulse width is out of the predetermined range, the fail counter will be incremented. If the failure counter exceeds the calibration, then the PCM is complete and a failure will be reported. If the sample counter threshold is reached before the failure threshold, then the PCM is complete and pass will be reported.
This PCM will detect an open/short circuit in the secondary current sense input circuit, misfire on the entire bank for the secondary current sense input circuit, coil failure, and same internal Ignition Current Sense System (ICSS) module faults.

Conditions for setting the DTC
- Ignition voltage is between 10 volt and 16 volts.
- MAP sensor signal is between 26 kPa and 100 kPa.
- Fuel level is more than 10%.
- Engine speed is between 650 rpm and 6500 rpm.
- ION Sensing Module circuit is open or shorted signals on the SEC 1 line.

Action Taken When the DTC Sets
- The PCM will illuminate the malfunction indicator lamp (MIL) the first time the fault is detected.
- The PCM calculates an air flow value based on Idle air Control valve position, throttle position, RPM and barometric pressure.
- The PCM will store condition which were present when the DTC was set as Freeze Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC
- The PCM will turn the MIL "OFF" on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
- A history DTC P1311 will clear after 40 consecutive trip cycle during which the warm up cycles have occurred without a fault.
- DTC P1311 can be cleared using the Tech 2 "Clear Info" function or by disconnecting the PCM battery feed.

Diagnostic Aids
An intermittent may be caused by the following:
- Poor connections.
- Mis routed harness.
- Rubbed through wire insulation.
- Broken wire inside the insulation. Check for the following conditions:
- Poor connection at PCM - Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness - Inspect the wiring harness for damage. If the harness appears to be OK, observe the moving connectors and wiring harnesses related to the sensor.
- A change in the display will indicate the location of the fault. If DTC P1311 cannot be duplicated, the information included in the Failure Records data can be useful in determined vehicle mileage since the DTC was last set.
- If it is determined that the DTC occurs intermittently, performing the DTC P1311 Diagnostic Chart may isolate the cause of the fault.

Steps 1 - 5:

Steps 6 - 10:

Step 11:

Test Description