Circuit Description
Important: Do not perform this check if no driveability concern exists.
The Diagnostic System Check - Manual Transmission is an organized approach to identifying a condition created by an electronic engine control system malfunction. The Diagnostic System Check - Manual Transmission is the starting point for any driveability concern diagnosis. This directs the service technician to the next logical step in order to diagnose the concern. Understanding the table and using it correctly will reduce diagnostic time, and will prevent the replacement of good parts.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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In order to correctly diagnosis any driveability malfunctions, the scan tool must be able to power-up.
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The diagnostic tables in this portion of the service manual are designed for use with a properly functioning scan tool. Serial data communication must be corrected before beginning any other diagnostic procedures. Class 2 serial data will not transmit if the system voltage is less than 9 volts or more than 16 volts.
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By storing the Freeze Frame and Failure Records data on the scan tool, an electronic copy of the data is created when the malfunction occurred. This information is stored on the scan tool and can be referred to later. Type C DTCs do not store Freeze Frame data. If this option is not available, manually record the information for later reference.
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If multiple DTCs are stored, diagnose the DTCs in the following order:
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After the engine reaches a normal operating temperature, compare the actual control system data with the typical values. This comparison is a quick way to determine if any parameter is not within limits. Remember that a base engine condition such as advanced cam timing may substantially alter sensor values.
Inspect the following sensors for proper operation:
| 1. | System voltage DTCs |
| 2. | PCM Error DTCs |
| 3. | Component level DTCs, or DTCs that indicate a malfunctioning part |
| 4. | System level DTCs, or DTCs that indicate a system malfunction |
| • | The engine coolant temperature (ECT) sensor |
| • | Inspect for an initial coolant temperature reading that is close to ambient, then observe the rise in temperature to the normal operating temperature while the engine is warming up. |
| • | The throttle position (TP) sensor |
| • | Inspect for proper sweep from 0-100 percent. |
| • | The manifold absolute pressure (MAP) sensor |
| • | Inspect for quick changes during changes in various engine loads. |
| • | The oxygen sensor (O2S 1) |
| • | Inspect for proper rich/lean and lean/rich sweeps in operation. |
| • | The idle air control (IAC) valve |
| • | Inspect for proper idle control and proper transition while operating the high load components such as the air-conditioning (A/C) control. |
| • | Inspecting the sensors for proper operation during warm-up can be a crucial step in correctly diagnosing any driveability concern. Careful observation of these sensors during engine warm-up may reveal a slow responding sensor or a sensor that malfunctions only within a small portion of its range. |
| • | Review any published service bulletins that relate to the exhibited symptoms or to components operation. |
Step | Action | Value(s) | Yes | No | ||||||||||||||||||||||||
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Important:
Does the scan tool power-up? | -- | Go to Step 2 | Go to Scan Tool Does Not Power Up in Data Link Communications | |||||||||||||||||||||||||
Does the scan tool display the PCM data? | -- | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |||||||||||||||||||||||||
3 | Attempt to start the engine. Does the engine start and continue to run? | -- | Go to Step 4 | Go to Engine Cranks but Does Not Run in Engine Controls - 2.4L (LN2) or Engine Cranks but Does Not Run in Engine Controls - 2.4L (L61) or Engine Cranks but Does Not Run in Engine Controls - 2.4L | ||||||||||||||||||||||||
4 | With the scan tool, check the following modules for DTCs.
Does the scan tool display any PCM DTCs? | -- | Go to Step 5 | Go to Step 7 | ||||||||||||||||||||||||
Record the Freeze Frame and Failure Records information with the scan tool. Did you complete the action? | -- | Go to Step 6 | -- | |||||||||||||||||||||||||
Were any of the PCM DTCs P0601, P0602, or P1621? | -- | Go to DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 in Engine Controls - 2.4L (LN2) or DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 in Engine Controls - 2.4L (L61) or DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 in Engine Controls - 2.4L | ||||||||||||||||||||||||||
7 | Were any BCM DTCs set? | -- | Go to Diagnostic Trouble Code (DTC) List in Body Control System | Go to Step 8 | ||||||||||||||||||||||||
8 | Is the customer concern with the Inspection/Maintenance (I/M) testing? | -- | Go to Inspection/Maintenance (I/M) System Check in Engine Controls - 2.4L (LN2) or Inspection/Maintenance (I/M) System Check in Engine Controls - 2.4L (L61) or Inspection/Maintenance (I/M) System Check in Engine Controls - 2.4L | Go to Step 9 | ||||||||||||||||||||||||
Are the display values normal or within typical ranges? | -- | Go to Step 10 | ||||||||||||||||||||||||||
10 | If the customer concern is a symptom, refer to the following tables:
Did you complete the action? | -- | System OK | Go to Intermittent Conditions in Engine Controls - 2.4L (LN2) or Intermittent Conditions in Engine Controls - 2.4L (L61) or Intermittent Conditions in Engine Controls - 2.4L |
