Circuit Description
The ignition system provides the spark to ignite the compressed air-fuel mixture in each cylinder at the right time. There are two ignition control assemblies located in the camshaft cover of each cylinder bank. Each assembly contains a control module, and four of the eight ignition coils. Each coil connects directly to a spark plug using a boot, thus eliminating the need for the secondary ignition wires. The assemblies receive ignition voltage from a fused circuit, and connect to chassis ground. Four of the eight ignition control (IC) circuits and a reference low circuit connect each module assembly to the PCM. The PCM uses the IC circuits to send timing pulses to the ignition control module. This signals the ignition module to trigger the coil and fire the spark plug.
The PCM checks the IC circuits for an improper voltage condition. The PCM is able to separately detect an IC circuit shorted to ground. However, the PCM cannot separately detect a short to voltage, or an open circuit. Therefore, the PCM checks the IC circuits for this condition in two groups. The two groups consist of every other cylinder in the engine firing order (that is: 1, 7, 4, 6 and 2, 3, 5, 8). If the PCM detects an improper voltage condition in the IC circuit group for #1, #4, #6, and #7 cylinders, DTC P1359 will set.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | During PCM power-up, the PCM detects an open circuit condition in the IC circuit group for #1, #4, #6, and #7 cylinders. |
| OR |
| • | The PCM detects a short to voltage condition in the IC circuit group for #1, #4, #6, and #7 cylinders. |
| • | The condition is present for less than 1 second. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails. |
| • | The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes. |
| • | 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 Clear DTC Information function. |
Diagnostic Aids
The Misfire Current Cyl # / Misfire History Cyl # displays on the scan tool provides information that may be useful in diagnosing DTC P1359. The Misfire Current Cyl # counter may normally display a small amount of activity (0-10 counts). However, the display should not increment steadily. If the Misfire Current Cyl # increments steadily for a single cylinder within the IC circuit group, the condition is isolated to the IC circuit for the specific cylinder. However, if the Misfire Current Cyl # increments randomly within the IC circuit group, the condition may be due to poor connections at the PCM or a faulty PCM. Also, if the Misfire Current Cyl # increments steadily for a cylinder bank, DTC P1360 may set. DTC P1360 may result from one of the following conditions:
| • | A loss of power or ground at the module assembly for the cylinder bank |
| • | A faulty or disconnected module assembly connector for the cylinder bank |
| • | A faulty ignition control module |
If the condition is intermittent, refer to Intermittent Conditions .
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||||||||
2 | Is DTC P1360 also set? | -- | ||||||||
3 | With the engine idling, observe the Misfire Bar Graph display on the scan tool. Is the Misfire Bar Graph incrementing for an even cylinders? | -- | ||||||||
4 | Is the Misfire Bar Graph Bar Graph incrementing for an odd cylinders? | -- | ||||||||
5 | With the engine idling, observe the Misfire Bar Graph display on the scan tool. Is the Misfire Bar Graph incrementing for two cylinders? | -- | ||||||||
6 |
Did you find and correct the condition? | -- | ||||||||
7 |
Did you find and correct the condition? | -- | ||||||||
8 | Are the incrementing cylinders even (cylinders 4 and 6)? | -- | ||||||||
9 |
Did you find and correct the condition? | -- | ||||||||
10 |
Did you find and correct the condition? | -- | ||||||||
11 |
Does the DMM display a frequency within the specified values? | 1-2 Hz | ||||||||
12 |
Did you find and correct the condition? | -- | ||||||||
13 |
Did you find and correct the condition? | -- | ||||||||
14 | Replace the appropriate ignition module. Refer to Ignition Control Module Replacement - Bank 1 or Ignition Control Module Replacement - Bank 2 . Did you complete the replacement? | -- | -- | |||||||
15 |
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | |||||||
16 |
Does the scan tool indicate that DTC P1359 passed? | -- | System OK |
