Trouble Code: P1350 (4.6L V8 VIN 9 Auto)Ignition Control (IC) Circuit Malfunction
/ Print this code data

Number of Trips to Set Code: 2

OBD II Monitor Type:CCM Details
Indicators:MIL Details

  • CCM Details
  • MIL Details

Trouble Code Conditions:

DTC P0322 and P1376 not set, engine cranking with at least one 4X REF pulse detected, and the PCM detected Ignition Control (IC) pulses with the engine cranking, or it detected at least one 4X REF pulse while it did not detect any IC pulses with the engine running.

Possible Causes:

  • Bypass circuit is open, shorted to ground or shorted to power
  • IC signal circuit is open, shorted to ground or shorted to power
  • IC module has failed

1999 Cadillac Seville - Powertrain - Engine Controls - 4.0L and 4.6L - DTC P1350 Ignition Control System

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PATH:DiagnosticsDiagnostic RoutinesPowertrainEngine Controls - 4.0L and 4.6LDTC P1350 Ignition Control System

DTC P1350 Ignition Control System
NOTE
Applicable vehicles:
  • Seville (VIN K)

DTC P1350 Ignition Control System

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Circuit Description

Under normal system operation when the key is turned ON and until engine RPM is high enough for the PCM to control spark, the PCM will open the bypass circuit (CKT 424) to the Ignition Control Module, the IC module will then ground the Ignition Control circuit (CKT 423). This is called module mode because the IC module is controlling spark. Once the engine speed is high enough (about 65 RPM), 4X reference pulses are received and no PCM faults are detected the PCM will close the bypass line and in response the IC module will unground the IC circuit, this allows PCM control of spark. This is called the ignition control mode. This diagnostic test is used to check for faults in both the bypass circuit and the IC circuit. To check both circuits this diagnostic runs two tests, one during crank and one while running. If Ignition Control pulses are detected by the PCM on the IC line while in module mode (cranking) or if no Ignition Control pulses are detected by the PCM while in ignition control mode (running) DTC P1350 will set.

Conditions for Running the DTC

  • Cranking Test
  • DTC P1376 not set.
  • At least 1 4X reference pulse has been received by the PCM.
  • Running Test
  • DTC P0322 and P1376 not set.
  • At least 1 4X reference pulse has been received by the PCM.

Conditions for Setting the DTC

  • Cranking Test
  • Ignition Control pulses are received by the PCM when cranking or running test has failed THIS ignition cycle.
  • Running Test
  • No Ignition Control pulses are received by the PCM while engine is running.

Action Taken When the DTC Sets

  • PCM ignition control is disabled for ignition cycle.
  • PCM disables EGR.
  • Transaxle shift adapts are maintained at current levels.
  • The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
  • The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

Conditions for Clearing the MIL/DTC

  • The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
  • A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
  • A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
  • Use a scan tool to clear DTCs.
  • Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

Diagnostic Aids

If fault is not present check terminal contact at the IC module and PCM connectors.

Test Description

  1. When checking for shorts to ground, resistance of more than 10K ohms is usually acceptable although most readings should be infinite (OL).

When checking for circuit continuity (opens) resistance should be 5 ohms or less.

When checking for shorts to voltage take measurements with the ignition ON and OFF.

Disconnect the circuit from all components before performing any circuit check.

Always check or zero the meter before performing resistance checks.

  1. A diagnostic jumper can be created with the terminals supplied in the J-38125 . Assemble the jumpers and terminals and cover the exposed terminals with heat shrink tubing. Do not cover the spade of the male terminals.

If the vehicle stalls during this step turn the ignition OFF and wait 30 seconds then restart the engine before attempting to measure the circuit voltage.

  1. If the vehicle stalls during this step turn the ignition OFF and wait 30 seconds then restart the engine before attempting to measure the circuit voltage.

Step / Action / Value(s) / Yes / No
1 / Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? / -- / Go to Step 2 / Go to the Powertrain On Board Diagnostic (OBD) System Check
2 / Are DTCs P0322, P0372, P1323, P1371, P1375 or P1376 also set? / -- / Go to DTCs that are set / Go to Step 3
3 /
  1. Turn the ignition OFF
  2. Wait 30 seconds.
  3. Turn the ignition ON but do not crank the engine.
  4. Using the scan tool store the snapshot info for DTC P1350 and then clear DTC P1350.
  5. After clearing the DTC start and idle the engine.
Does P1350 fail this ignition? / -- / Go to Step 4 / Fault not present, go to Diagnostic Aids.
4 /
  1. Record the fluid life indexes.
  2. Turn the ignition OFF.
  3. Wait 30 seconds.
  4. Disconnect PCM connector C2 and IC Module connector C4.
  5. Using the DMM check the Bypass and Ignition Control circuits for high resistance, shorts to ground, shorts to voltage and shorts to other circuits. Refer to Test Descriptions.
  6. Repair circuits as needed.
Was a repair made to any circuit? / -- / Go to Powertrain Control Module Diagnosis / Go to Step 5
5 /
  1. Reconnect PCM connector C2.
  2. Turn the ignition ON but DO NOT crank the engine.
  3. Using the DMM measure the DC voltage to ground on the Bypass circuit and then the Ignition Control circuit.
Is the voltage less than the value specified? / 1.0 volts / Go to Step 6 / Go to Step 11
6 /
  1. Turn the ignition OFF.
  2. Wait 30 seconds.
  3. Install diagnostic jumper at IC module C4.
OR:
  • Jumper C4 terminal A to module pin A.
  • Jumper C4 terminal B to module pin B.
  • Jumper C4 terminal C to module pin C.
  • Jumper C4 terminal D to module pin D.
  • Jumper C4 terminal E to module pin E.
  • Jumper C4 terminal F to module pin F.
  1. Disconnect the Ignition Control and Bypass circuit jumpers (terminals D and E). Ensure jumpers are away from contacting other circuits, engine ground or each other.
  2. Start and idle the engine.
  3. Measure the DC voltage to ground on the Ignition Control circuit FROM the PCM.
Is the voltage fixed near the value specified? / 1.7 volts / Go to Step 7 / Go to Step 11
7 / Measure the DC voltage to ground on the Bypass circuit FROM the PCM.
Is the voltage less than the value specified? / 1.0 volts / Go to Step 8 / Go to Step 11
8 /
  1. Momentarily ground the Ignition Control circuit.
  2. Measure the DC voltage to ground on the Bypass circuit FROM the PCM.
Is the voltage the same or more than the value specified? / 4.7 volts / Go to Step 9 / Go to Step 11
9 /
  1. Check terminal contact at the IC Module connector C4.
  2. Repair terminal contact if needed.
Was terminal contact repaired? / -- / Go to Powertrain Control Module Diagnosis / Go to Step 10
10 / Replace the Ignition Control Module. Refer to Ignition Control Module Replacement .
Is the replacement complete? / -- / Go to Powertrain Control Module Diagnosis / --
11 /
  1. Check terminal contact at PCM connector C2.
  2. Repair terminal contact if needed.
Was terminal contact repaired? / -- / Go to Powertrain Control Module Diagnosis / Go to Step 12
12 / Replace the PCM. Refer to Powertrain Control Module Replacement .
Is the replacement complete? / -- / Go to Powertrain Control Module Diagnosis / --

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Trouble Code: P1375 (4.6L V8 VIN 9 Auto)IC Module 24X Reference Circuit High Input
/ Print this code data

Number of Trips to Set Code: 2

OBD II Monitor Type:CCM Details
Indicators:MIL Details

  • CCM Details
  • MIL Details

Trouble Code Conditions:

DTC P1376 not set, engine started, engine speed over 496 rpm, at least 7 CMP pulses detected since key "on", and the PCM detected the 24X signal was high, and that it did not receive any 24X REF pulses during the last eight (8) 4X REF pulses during the CCM test.

Possible Causes:

  • CKP Sensor 'A' signal circuit is open or shorted to ground
  • Crank Sensor 'A' is damaged or has failed
  • Crank Sensor 'B' low circuit is shorted to CKP 'A' high circuit
  • Crank Sensor 'B' is damaged or has failed
  • IC module is damaged or has failed
  • PCM had failed

1999 Cadillac Seville - Powertrain - Engine Controls - 4.0L and 4.6L - DTC P1375 IC 24X Reference Circuit High Voltage

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PATH:DiagnosticsDiagnostic RoutinesPowertrainEngine Controls - 4.0L and 4.6LDTC P1375 IC 24X Reference Circuit High Voltage

DTC P1375 IC 24X Reference Circuit High Voltage
NOTE
Applicable vehicles:
  • Seville (VIN K)

DTC P1375 IC 24X Reference Circuit High Voltage

Refer to Engine Controls Schematic References .

Circuit Description

This diagnostic test checks for 24X signal at a logic high condition. The fault could be induced by the failure of either Crankshaft Position A or B Sensor input signal to the Ignition Control Module. Under such a condition, the Ignition Control Module would force the 24X signal high. This DTC will also set if the 24X signal is shorted to voltage externally. If either condition is met DTC P1375 is set.

Conditions for Running the DTC

  • DTC P1376 is not set.
  • Engine speed greater than 496 RPM.
  • At least 7 CAM pulses received since key ON.

Conditions for Setting the DTC

24X signal voltage is high and no 24X reference pulses have been received during the last 8 4X reference pulses.

Action Taken When the DTC Sets

  • The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
  • The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

Conditions for Clearing the MIL/DTC

  • The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
  • A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
  • A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
  • Use a scan tool to clear DTCs.
  • Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. Checking for a faulty crank A sensor or circuit failure.
  1. Checking for a faulty crank B sensor or circuit failure.
  1. To ensure accurate voltage readings, connect the DMM to the sensor before recording the Peak Min Max voltage.
  1. To ensure accurate voltage readings, connect the DMM to the sensor before recording the Peak Min Max voltage.

Step / Action / Value(s) / Yes / No
1 / Was the On-Board Diagnostic (OBD) System Check? / -- / Go to Step 2 / Go to Powertrain On Board Diagnostic (OBD) System Check
2 / Is DTC P1376 also set? / -- / Go to DTC P1376 Ignition Ground Circuit / Go to Step 3
3 /
  1. Turn the key to LOCK.
  2. Disconnect IC module connector C1.
  3. Using DMM measure the resistance between connector terminals A and B (harness side).
Is the resistance between the range specified? / 800 - 1600 ohms / Go to Step 4 / Go to Step 11
4 / Measure the resistance between connector terminals E and F.
Is the resistance between the range specified? / 800 - 1600 ohms / Go to Step 5 / Go to Step 14
5 / Measure the resistance to ground at IC module connector C1 terminals A then B then E and then F.
Is the resistance at any terminal less than the value specified? / OL / Go to Step 17 / Go to Step 6
6 /
  1. Disconnect IC module connector C2.
  2. Set DMM to peak min/max, 4 volt scale, 1 ms sampling rate. Refer to Test Descriptions.
  3. Measure the max DC voltage across IC module connector C1 terminals A and B.
  4. Crank the engine for 10 seconds.
Is the voltage measured while cranking greater than the value specified? / 0.25 volts / Go to Step 7 / Go to Step 19
7 /
  1. Set DMM to peak min/max, 4 volt scale, 1 ms sampling rate. Refer to Test Descriptions. Measure the max DC voltage across IC module connector C1 terminals E and F.
  2. Crank the engine for 10 seconds.
Is the voltage measured while cranking greater than the value specified? / 0.25 volts / Go to Step 8 / Go to Step 20
8 /
  1. Reconnect IC module connectors C1 and C2.
  2. Disconnect IC module connector C4.
  3. Record the fluid life indexes, turn the key to LOCK and wait 30 seconds. Disconnect PCM connector C2.
  4. Turn the key ON.
  5. Measure the voltage to ground at PCM connector C2 terminal 5.
Is the voltage less than the value specified? / 0.4 volts / Go to Step 9 / Go to Step 18
9 /
  1. Turn the key to OFF.
  2. With PCM connector C2 disconnected, remove terminal 5 and reconnect PCM connector C2.
  3. Connect the DMM to terminal 5 and ground.
  4. Set the DMM to D/C scale and push the Hz button.
  5. Start the engine and idle.
Does the FREQUENCY measure more than the value specified? / 0 Hertz / Go to Step 10 / Go to Step 25
10 /
  1. Clear all DTCs.
  2. Remove the DMM and leave terminal 5 removed.
  3. Start the engine.
  4. In DTC Info select Fail This Ign.
Does DTC P1323 set? / -- / Fault not present. / Go to Step 27
11 / Was the resistance lower in step 3 than the range that was specified? / -- / Go to Step 12 / Go to Step 13
12 /
  1. Disconnect crank sensor A connector at sensor.
  2. Measure resistance across terminals A and B at the sensor connector (harness side).
Is the resistance lower than the value specified? / OL / Go to Step 21 / Go to Step 19
13 /
  1. Disconnect crank sensor A connector at sensor.
  2. Jumper terminals A and B together at the sensor connector (harness side).
  3. Measure the resistance across IC module connector C1 terminals A and B.
Is the resistance more than the value specified? / 5 ohms / Go to Step 22 / Go to Step 19
14 / Was the resistance lower in step 4 than the range that was specified? / -- / Go to Step 15 / Go to Step 16
15 /
  1. Disconnect crank sensor B connector at sensor.
  2. Measure resistance across terminals A and B at the sensor connector (harness side).
Is the resistance lower than the value specified? / OL / Go to Step 23 / Go to Step 20
16 /
  1. Disconnect crank sensor B connector at sensor.
  2. Jumper terminals A and B together at the sensor connector (harness side).
  3. Measure the resistance across IC module connector C1 terminals E and F.
Is the resistance more than the value specified? / 5 ohms / Go to Step 24 / Go to Step 20
17 / Repair the short to ground in the circuit(s) that measured low in step 5.
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
18 / Repair the short to voltage on the 24X Spark Reference circuit.
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
19 / Replace crank sensor A. Refer to Crankshaft Position Sensor Replacement .
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
20 / Replace crank sensor B. Refer to Crankshaft Position Sensor Replacement .
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
21 / Repair the Crank A High circuit and the Crank A Low Circuit shorted together.
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
22 / Repair the open in the Crank A High circuit and/or the Crank A Low circuit.
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
23 / Repair the Crank B Low circuit and the Crank B High circuit shorted together.
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
24 / Repair the open in the Crank B Low circuit and/or the Crank B High circuit
Is the repair complete? / -- / Go to Powertrain Control Module Diagnosis / --
25 /
  1. Check terminal contact at the IC module connector C1 terminals A, B, E and F.
  2. Repair terminal contact if needed.
Was terminal contact repaired? / -- / Go to Powertrain Control Module Diagnosis / Go to Step 26
26 / Replace the Ignition Control Module. Refer to Ignition Control Module Replacement .
Is the replacement complete? / -- / Go to Powertrain Control Module Diagnosis / --
27 /
  1. Check terminal contact at the PCM connector C2 terminal 5.
  2. Repair terminal contact if needed.
Was terminal contact repaired? / -- / Go to Powertrain Control Module Diagnosis / Go to Step 28
28 / Replace the PCM. Refer to Powertrain Control Module Replacement .
Is the replacement complete? / -- / Go to Powertrain Control Module Diagnosis / --

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