DTC P1361 Ignition Control (IC) Circuit Low Voltage. Oldsmobile Shelby Series 1 1999

For 1990-2009 cars
Engine Controls Components
Ignition Control Module
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

### 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.

#### DTC P1361 - IC Circuit Not Toggling

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check

2

1. Start the engine and let idle for 2 minutes.
2. Observe the DTCs.

Did DTC P1361 set?

--

Go to Step 3

Go to Diagnostic Aids

3

1. Turn the ignition OFF.
2. Disconnect the PCM C2 connector.
3. Install a test lamp between B+ and the bypass circuit at the PCM harness connector.

Is the test lamp ON?

--

Go to Step 8

Go to Step 4

4

1. Turn the ignition ON.
2. With the test lamp installed between B+ and the bypass circuit, measure the resistance between the IC circuit and the reference low circuit using a DVM.

Is resistance more than the specified value?

6,000 ohms

Go to Step 12

Go to Step 5

5

1. Turn the ignition OFF and disconnect the ignition control module C4 connector.
2. Probe the IC circuit with a test lamp to B+.

Is the test lamp ON?

--

Go to Step 10

Go to Step 6

6

1. Check the bypass circuit for an open.
2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a problem found?

--

Go to Step 15

Go to Step 7

7

1. Check the bypass circuit for a poor terminal connection at the ignition control module.
2. If a problem is found, replace faulty terminal. Refer to Connector Repairs in Wiring Systems.

Was a problem found?

--

Go to Step 15

Go to Step 14

8

1. Turn the ignition OFF and disconnect the ignition control module C4 connector.
2. Turn the ignition ON and observe the test lamp connected between the bypass circuit and B+.

Is the test lamp ON?

--

Go to Step 11

Go to Step 14

9

1. Turn the ignition OFF and disconnect the ignition control module (ICM) C4 connector.
2. Turn the ignition ON and check the IC circuit for a short to voltage.
3. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 15

Go to Step 13

10 | Locate and repair short to ground in the IC circuit. Refer to Wiring Repairs in Wiring Systems. Is action complete? | -- | Go to Step 15 | --
11 | Locate and repair short to ground in the bypass circuit. Refer to Wiring Repairs in Wiring Systems. Is action complete? | -- | Go to Step 15 | --

12

1. Check the bypass circuit for a poor terminal connection at the PCM.
2. If a problem is found, repair as necessary. Refer to Connector Repairs in Wiring Systems.

Was a problem found?

--

Go to Step 15

Go to Step 13

13 | Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | Go to Step 15 | --
14 | Replace the ignition control module. Refer to Ignition Control Module Replacement . Is the action complete? | -- | Go to Step 15 | --

15

1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
2. Idle the engine at the normal operating temperature.
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this diagnostic ran and passed?

--

Go to Step 16

Go to Step 2

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