DTC P1350 Bypass Line Monitor
Refer to Ignition Control
, Knock Sensors .
The Ignition Control Module (ICM) sends signals that the PCM requires for fuel control
and spark advance calculations. At the start of engine crank, the ICM controls spark advance (Bypass mode.) When the second 3X reference pulse is recognized by the PCM, the PCM applies 5 volts to the Bypass circuit, commanding the ICM to switch spark advance to PCM control (IC mode). An open in the IC circuit
or a short to voltage in the Bypass circuit at startup will cause the PCM to monitor IC pulses during crank, when the ICM should be grounding the IC circuit. This condition will set DTC P1350. The engine may be started but will run on Bypass mode timing.
Conditions for Setting the DTC
The PCM monitors IC pulses during crank while Bypass mode spark advance is commanded
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
Conditions for Clearing the MIL/DTC
The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using the scan tool.
Check for the following conditions:
Poor connection at the PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection
. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the ICM, turn the ignition ON and observe a digital multimeter connected between the IC circuit and B+ while moving connectors and wiring harnesses
related to the ICM. A change in voltage will indicate the location of the malfunction.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Number(s) below refer to the step number(s) on the Diagnostic Table.
This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.