GM Service Manual Online
For 1990-2009 cars only

Object Number: 13321  Size: LF
Engine Controls Components
Ignition Control (IC) Module
OBD II Symbol Description Notice
ESD Notice
ESD Notice

Circuit Description

The diagnostic test checks for an engine stall or near stall and sets DTC P1599 if a stall condition is detected. A partial start where engine RPM exceeds 400 RPM and the engine does not start, will also cause DTC P1599 to set. This DTC is designed to capture snapshot data of the stall condition. This DTC may set as the ignition is turned OFF if the injectors or IC Module lose power before the PCM.

Conditions for Setting the DTC

Test Condition

Ignition turned ON.

Failure Conditions

    •  Engine speed drops below 152 RPM after exceeding 400 RPM this ignition cycle.
        OR
    •  No references pulses have been received for 0.75 second after receiving pulses.

Action Taken When the DTC Sets

    •  The Malfunction Indicator Lamp (MIL) will not illuminate.
    •  No message will be displayed.

Conditions for Clearing the DTC

    •  A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
    •  A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
    • 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

Since many things can cause a stalling condition use the snapshot taken of DTC P1599 to compare the values taken when the DTC set to the Typical Scan Data Value table. Look for conditions that could have caused the stall and how long ago the stall occurred.

Test Description

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

  1. If the customer does not have a stall complaint, ignore this DTC.

  2. Check for other DTCs that may have caused a stalling condition to occur.

  3. This DTC may set during a severe stumble or hesitation. If such is the case, diagnose the condition using the symptom diagnosis charts.

  4. This step lists most of the possible causes of stalling arranged by subsystem.

Step

Action

Value(s)

Yes

No

1

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

--

Go to Step 2

Go to A Powertrain On Board Diagnostic (OBD) System Check

2

Is customer complaining of stalling?

--

Go to Step 3

Fault not present. Refer to Diagnostic Aids

3

Turn the key ON.

Are any other DTCs set?

--

Go to DTCs that are set

Go to Step 4

4

  1. Using a scan tool locate the Stall Data. This is the snapshot taken when the vehicle stalled and is not located with the Failure Records.
  2. Check the MAP sensor display taken at the time this DTC was set.

Is the display more than the value specified?

95 kPa

Go to Step 5

Refer to Symptoms

5

  1. One or more of the following systems may have caused the stalling condition.
  2. • Idle Speed Control.
    • Emissions System.
    • Fuel System.
    • Wiring and connections.
  3. Perform Fuel System Check chart, view Test Description on facing page.

Was a fault found and repaired?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Go to Step 6

6

  1. Check for TCC improperly applied by a grounded TCC solenoid circuit or by transaxle hydraulic problems. Refer to Section 7 to diagnose.
  2. Check ignition switch circuits for intermittent open to the PCM or ignition control module. Manipulate the key switch while driving to check for ignition switch intermittent or out of adjustment.
  3. Check PCM ground and ignition control module ground.
  4. Check for intermittent injector circuit operation.
  5. Check the fuel PUMP ground for a loose or poor connection.

Did any of the checks above require a repair?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Refer to Diagnostic Aids