Circuit Description
The ignition control module (ICM) sends signals that the powertrain control module (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 4X reference pulse is recognized by the PCM, the PCM applies 5 volts to the bypass circuit. The 5 volts on the bypass circuit commands the ICM to switch spark advance to PCM control (IC mode). At this time, the ICM will remove the ground it has applied to the ignition control (IC) circuit. When the IC pulses are not grounded, the ICM can use the IC pulses to control spark advance. A short in the IC circuit or an open or short to ground in the bypass circuit will cause the PCM to monitor no IC pulses after the PCM has switched the bypass circuit ON. The PCM will set DTC P1361 under either of these conditions. The engine may be started but will run on Bypass mode timing.
Conditions for Setting the DTC
| • | The PCM does not monitor IC pulses while IC mode spark advance is commanded. |
| • | The engine speed is more than 600 RPM. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) the first time the malfunction is detected. |
| • | 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. |
Diagnostic Aids
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, disconnect the ICM, turn the ignition ON, and observe a voltmeter 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 fault. |
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.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 |
Did DTC P1361 set? | -- | Go to Diagnostic Aids | |
3 |
Is the test lamp ON? | -- | ||
4 |
Is resistance more than the specified value? | 6,000 ohms | ||
5 |
Is the test lamp ON? | -- | ||
6 |
Was a problem found? | -- | ||
7 |
Was a problem found? | -- | ||
8 |
Is the test lamp ON? | -- | ||
9 |
Was a problem found? | -- | ||
10 | Locate and repair short to ground in the IC circuit. Refer to Wiring Repairs in Wiring Systems. Is action complete? | -- | -- | |
11 | Locate and repair short to ground in the bypass circuit. Refer to Wiring Repairs in Wiring Systems. Is action complete? | -- | -- | |
12 |
Was a problem found? | -- | ||
13 |
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | |
14 | Replace the ignition control module. Refer to Ignition Control Module Replacement . Is the action complete? | -- | -- | |
15 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | ||
16 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
