For 1990-2009 cars
Engine Controls Components
Power, Ground, CMP, CKP 24X, CKP 7X, KS, and ICM
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The ignition control (IC) module sends signals that the powertrain control module (PCM) requires for fuel control and spark advance calculations. At the start of engine crank, the IC module 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 IC module to switch spark advance to PCM control, IC mode. If the PCM detects an open in the Bypass circuit, DTC P1352 will set. The engine will start and may run in Bypass mode timing.

### Conditions for Running the DTC

The engine is running.

### Conditions for Setting the DTC

• | The PCM detects an open circuit in the Bypass circuit.

• | The condition is present for 300 3X reference periods, 100 crankshaft revolutions.

### 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/Failure Records data.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has 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 a scan tool.

### Diagnostic Aids

Inspect for the following conditions:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

• | Loose terminal connection

- | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

- | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

• | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

• | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

### Test Description

The numbers below refer to the step numbers on the diagnostic table:

1. This step ensures that the replacement PCM, which utilizes an electrically erasable programmable read only memory (EEPROM), is programmed when installed.

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. Turn OFF the ignition.
2. Disconnect the PCM.
3. Connect the DMM between the IC and Reference Low circuits.
4. Turn ON the ignition.
5. Probe the BYPASS circuit with a test lamp connected to battery positive voltage.

Does the DMM display a resistance above the specified value?

5,000ohms

Go to Step 4

Go to Step 3

3 |

1. Turn OFF the ignition.
2. Leave the PCM disconnected.
3. Disconnect the ignition control module connector.
4. Test for an open in the BYPASS circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 8

Go to Step 5

4 | Inspect for poor terminal connections at the PCM. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 7
5 | Inspect for poor terminal connections at the ignition control module. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6
6 | Replace the ignition control module. Refer to Ignition Control Module Replacement . Did you complete the replacement? | -- | Go to Step 8 | --
7 | Important: The replacement PCM must be reprogrammed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | Go to Step 8 | --
8 |

1. Review and record scan tool Fail Records data.
2. Clear DTCs.
3. Operate the vehicle within Fail Records conditions.
4. Using the scan tool, monitor Specific DTC Info for DTC P1352.

Does the scan tool indicate DTC 1352 failed this ignition?

--

Go to Step 2

System OK