For 1990-2009 cars

# SMU - Diagnostic Trouble Code (DTC) P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610

Subject: | Service Manual Update - Diagnostic Trouble Code (DTC) P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610

Models: | 2004 and 2005 Saturn L-Series Vehicles with 3.0L V-6 Engine (VIN R -- RPO L81)

Attention: | Fixed Operations Manager and Technician

This bulletin is being revised to add the 2005 model year. Please discard Corporate Bulletin Number 04-06-04-026 (Section 06 -- Engine).

### Purpose

The purpose of this bulletin is to provide updated Service Manual information for DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683 and P2610" in the Engine Controls - 3.0L (L81) section of the 2004 Saturn L-Series Service Manual, Vol. 1.

Please obtain all 2004 Saturn L-Series Service Manuals, Vol. 1, and cross out the chart for "DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683 and P2610" and insert the following text and chart for "DTC P0601- P0606" on page 6-1220 in the Engine Controls - 3.0L (L81) section.

Please obtain all 2005 Saturn L-Series Service Manuals, Vol. 1, and cross out the chart for "DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683 and P2610" and insert the following text and chart for "DTC P0601-P0606" on page 6-583 in the Engine Controls - 3.0L (L81) section.

The SI website will be updated immediately and future Service Stall System SI CD releases will include this and other Service Manual updates.

### DTC P0601 - P0606

Description

These diagnostics apply to internal microprocessor integrity conditions within the engine control module (ECM).

P0601 Control Module Memory

This DTC will set if the ECM has detected a fault with its read only memory (ROM). The ROM is checked continuously with ignition ON. The engine will not start if a fault is detected at start-up.

P0602 Control Module Not Programmed

Important: This DTC does NOT indicate a faulty ECM.

This DTC will set if the ECM is not programmed correctly, which does NOT infer that the ECM is at fault. The engine may not start if the ECM is or was not programmed correctly.

P0603 Control Module Long Term Memory Reset

This DTC will set if the ECM has registered an error in switching OFF its power stages to its memory devices. This condition is checked continuously with ignition ON.

P0604 Control Module RAM

This DTC will set if the ECM has detected a fault with its random access memory (RAM). The RAM is checked continuously with ignition ON.

P0606 Control Module Internal Performance

This DTC will set if the ECM has detected that the calculated engine torque has been out of range for longer than 6 seconds or a controller access network (CAN) communication error has occurred. Engine speed must be greater than 1120 RPM to run this diagnostic.

#### DTC P0601, P0602, P0603, P0604, P0606

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2. | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information.
2 | Record all DTC information and include with the repair information. Is DTC P0601, P0602, P0604, or P0606 set? | Go to Step 3. | Go to Step 5.
3 | Program the engine control module (ECM). Refer to Service Programming System (SPS) in Programming and Setup. Does the DTC reset? | Go to Step 4. | Go to Step 8.
4 |

1. Ensure that all tool connections are secure.
2. Ensure that the programming equipment is operating correctly.
3. Ensure that the correct software/calibration package is used.
4. Attempt to program the ECM.

Refer to Service Programming System (SPS) in Programming and Setup.

Does the DTC reset?

Go to Step 5.

Go to Step 6.

5 | Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 6. | - -
6 |

1. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.

Did the DTC fail this ignition?

Go to Step 2.

Go to Step 7.

7 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK