P1361

DTC P1361:

Ignition & Fuel Injection Wiring Schematic:

CIRCUIT DESCRIPTION
Ignition control (IC) spark timing is provided by the Powertrain Control Module (PCM) on CKT 423. Inputs from a number of engine sensors allow the PCM to correctly calculate optimum spark timing. Engine load is calculated from the Mass Air Flow (MAF) sensor, engine RPM is derived from the 3X crankshaft position sensor, engine operating temperature from Engine Coolant Temperature (ECT) and Intake Air Temperature (IAT) sensors, and engine knock activity from the knock sensor. Other engine functions modify spark to a lesser degree such as Torque Converter Clutch (TCC) engagement and Exhaust Gas Recirculation (EGR) activity.

The bypass circuit controls an internal switch in the electronic Ignition Control Module (ICM). Unless the vehicle is in backup spark (base timing mode), the bypass circuit will have 5 volts applied to it. This 5 volt signal from the PCM allows a solid state switch to direct the IC timing pulses to the ICM for sequencing and energizing the coil packs. If the bypass circuit is not energized, the IC pulses from the ICM are shunted to ground and the electronic ICM uses it's own base timing schedule to time and energize the coil packs.

DIAGNOSTIC TROUBLE CODE (DTC) P1361 WILL SET WHEN
No pulses are detected on the IC circuit by the PCM.

ACTION TAKEN (PCM WILL DEFAULT TO)
The PCM will allow the electronic ignition control module to control timing using its own base timing schedule. The Malfunction Indicator Lamp (MIL) will become illuminated.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test confirms DTC P1361 and that the fault causing the DTC is present.
2. Checks for a normal IC ground path through the ignition control module. A DTC P1361 indicates the PCM has detected an open or short to voltage IC circuit, or the bypass circuit grounded or shorted to voltage. An IC CKT 423 shorted to ground will also read less than 500 ohms; however, this will be checked later.
3. As the test light voltage touches CKT 424, the module should switch causing the ohmmeter to "overrange" if the meter is in the 1000-2000 ohms position. Selecting the 10-20,000 ohms position will indicate above 5000 ohms. The important thing is that the module "switched."
4. The module did not switch and this step checks for:

^ IC CKT 423 shorted to ground.
^ Bypass CKT 424 open.
^ Faulty electronic ignition control module connection or module.

5. Confirms that DTC P1361 is a faulty PCM and not an intermittent in CKT 423 or 424.

DIAGNOSTIC AIDS
The Tech 1 scan tool does not have any ability to help diagnose a DTC P1361 problem.

Refer to "Intermittents," in Diagnosis by Symptom. - Intermittent Malfunctions

Electronic Spark Timing (EST) Line
When CKT 423 is shorted voltage or open during crank, will set DTC P1350 also if CKT 424 is shorted to voltage during crank DTC P1350 will set.

EST Bypass Line
During engine run operation, if CKT 424 opens or shorts to ground, DTC P1361 will set. When DTC P1361 is stored DTC P1350 will not be set. If DTC P1350 is stored DTC P1361 also can be set.