GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 LeSabre 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 DTC P1352 Ignition Bypass Circuit High Voltage

Refer to

IC Module, CMP and CKP Sensors


Object Number: 410109 Size: FS
Engine Controls Components
Electronic Ignition (EI) System Description
Fuel Pump and Relay
MIL, Data Link Feed
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
IGN-1 Relay, TRANS, DIS, OXY SEN and IGN 1 Fuses (Underhood Fuse Block)
Handling ESD Sensitive Parts Notice
 in Engine Controls Schematics.

Circuit Description

TheiIgnition control module (ICM) sends signals that the PCM requires for fuel control and spark advance calculations. At the start of engine crank, the ICM controls spark advance. This is called the bypass mode. When the second 3X reference pulse is recognized by the PCM, the PCM applies 5 volts to the bypass circuit, commanding the ICM to switch spark advance to PCM control. This is called the 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.

Action Taken When the DTC Sets
    • The PCM illuminates the MIL during the second consecutive trip in which the diagnostic test runs and fails.
    • The PCM stores the conditions that were present when the DTC set as Freeze Frame and Fail Records data.

Conditions for Clearing the MIL/DTC
    • The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic runs and passes.
    • The history DTC clears after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear Information function or by disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

    • A faulty connection at the PCM--Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Use a corresponding mating terminal to test for proper terminal tension.
    • A 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 DMM 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 malfunction.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition occurs that caused the DTC to set. This may assist in diagnosing the condition.

Test Description

Numbers below refer to the step numbers on the Diagnostic Table:

  1. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

DTC P1352 - Bypass Circuit Open

Step

Action

Values

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Turn OFF the ignition switch.
  2. Disconnect the PCM.
  3. Connect a digital multimeter (DMM) between the IC and The reference low circuits at the PCM connector.
  4. Turn ON the ignition switch.
  5. Probe the BYPASS circuit with a test lamp connected to B+.

Does the DMM display voltage within the specified range?

150-250mV

Go to Step 4

Go to Step 3

3
  1. Turn OFF the ignition switch.
  2. Leave the PCM disconnected.
  3. Disconnect the ignition control module connector.
  4. Check for an open in the BYPASS circuit.
  5. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems .

Was a problem found?

--

Go to Step 8

Go to Step 5

4
  1. Check for faulty terminal connections at the PCM.
  2. If a problem is found, repair as necessary. Refer to Testing for Continuity , Repairing Connector Terminals and Connector Repairs in Wiring Systems.

Was a problem found?

--

Go to Step 8

Go to Step 7

5
  1. Check for faulty terminal connections at the ignition control module.
  2. If a problem is found, repair as necessary. Refer to Testing for Continuity , Repairing Connector Terminals and Connector Repairs in Wiring Systems.

Was a problem found?

--

Go to Step 8

Go to Step 6

6

Replace the ignition control module. Refer to Ignition Control Module Replacement .

Is the action complete?

--

Go to Step 8

--

7

Important: Replacement PCM must be reprogrammed.

Replace the PCM.

Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 8

--

8
  1. Review and record the scan tool Fail Records data.
  2. Clear the DTCs.
  3. Operate the vehicle within the Fail Records conditions.
  4. Using the scan tool, monitor the Specific DTC Info for DTC P1352.

Does the scan tool indicate DTC P1352 failed this ignition?

--

Go to Step 2

System OK