Circuit Description
The engine control module (ECM) has the ability to set a diagnostic trouble code (DTC) if the engine stalls when the ignition has not been turned OFF. This DTC may aid in intermittent diagnosis of a customer complaint of intermittent engine stall. The scan tool Failure Record information can be duplicated under the same stall conditions in an attempt to reproduce the occurrence. Since DTC P1599 is a type D DTC, the ECM will not command the malfunction indicator lamp (MIL) ON. This DTC can set due to a driver error. For example, a vehicle equipped with a manual transaxle in which the clutch was release too quickly causing the engine to stall, will set DTC P1599.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | The engine is in Run mode. |
| • | Ignition voltage is present at the ECM. |
| • | CKP pulses at ECM are not detected. |
Action Taken When the DTC Sets
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the Message/DTC
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
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. If other DTCs are set, especially DTC P0336, diagnose those DTCs first. |
| • | DTC P1599 may be set if the engine speed drops below 400 RPM, near stall, and then recovers. |
| • | If the condition is intermittent, refer to Intermittent Conditions . |
| • | Verify drive did not induce the stall condition. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- |
