The diagnostic system check is an organized approach to identify a problem created by an electronic engine control system malfunction. If must be the starting point for any driveability complaint diagnosis because it directs the technician to the next logical step in diagnosing the complaint. Understanding the table and using it correctly will reduce diagnostic time and prevent the unnecessary replacement of parts.
Step | Action | Yes | No |
---|---|---|---|
1 | Verify the customer complaints. Are the customer's complaints verified? | Go to Step 2 | -- |
2 | Turn ON the ignition. Is the malfunction indicator lamp (MIL) on steadily? | Go to Step 4 | Go to Step 3 |
3 | Jumper the data link connector (DLC) terminals 4, 5, and 6. Does the MIL flash code 12? | Go to Step 4 | |
4 |
Does the scan tool display serial data? | Go to Step 5 | Go to Step 12 |
5 | Start the engine. Does the engine start? | Go to Step 6 | |
6 |
Are any DTCs displayed? | Go to Step 8 | Go to Step 7 |
7 |
Are the values normal or within the normal range? | Go to Step 9 | Go to Step 10 |
8 | Refer to the applicable DTC table. Start with the DTC with the lowest numerical value and move up. Are the DTCs identified as valid trouble codes? | Go to applicable DTC table | Go to Step 6 |
9 | Are there any symptoms that have been identified? | Go to applicable DTC table | Go to Step 11 |
10 | Identify the component that has a serial data value outside the normal range. Has the component been identified? | Go to Diagnostic Aids | -- |
11 |
Is the repair complete? | System OK | Go to Step 1 |
12 |
Does the scan tool read serial data? | Go to Step 13 | Go to Step 16 |
13 | Test for an open or short in the wire between ECM terminal D11 and the DLC connector 9. Is the problem found? | Go to Step 14 | Go to Step 15 |
14 |
Does the scan tool display serial data? | System OK | Go to Step 15 |
15 |
Does the scan tool display serial data? | Go to Step 6 | -- |
16 |
Does the scan tool read serial data? | Go to Step 5 | -- |
The Diagnostic System Check-Engine Controls is an organized approach to identifying a condition that is created by a malfunction in the engine control system. The Diagnostic System Check must be the starting point for any driveability concern. The Diagnostic System Check directs the service technician to the next logical step in order to diagnose the concern. Understanding and correctly using the diagnostic table reduces diagnostic time and prevents the replacement of good parts.
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Perform the following preliminary inspections:
Did you find and correct the condition? | System OK | Go to Step 2 | ||||||||||
2 |
Does the scan tool turn ON? | Go to Step 3 | Go to Scan Tool Does Not Power Up in Data Link Communications | ||||||||||
3 |
Does the scan tool communicate with the ECM? | Go to Step 4 | Go to Scan Tool Does Not Communicate with Component in Data Link Communications | ||||||||||
4 | Attempt to start the engine. Does the engine crank? | Go to Step 5 | Go to Symptoms - Engine Electrical in Engine Electrical | ||||||||||
5 | Did the engine start and idle? | Go to Step 6 | |||||||||||
6 |
Important: Do NOT clear the DTCs unless instructed by a diagnostic procedure.
Begin with the lowest number DTC unless the diagnostic table directs you otherwise.
Does the scan tool display any DTCs? | Go to Step 7 | Go to Step 10 | ||||||||||
7 | Does the scan tool display DTCs P1601, P1607, P1650, P1655? | Go to Step 8 | |||||||||||
8 | Does the scan tool display DTCs P0601, P0602, or P0607? | Go to Step 9 | |||||||||||
9 | Does the scan tool display DTCs P0562 or P0563? | ||||||||||||
10 | Are there any TCM DTCs or any automatic transmission symptoms? | Go to Diagnostic System Check - Automatic Transmission in Automatic Transmission - Aisin (ZF 4HP 16) | Go to Step 11 | ||||||||||
Are there any engine controls or driveability symptoms observed? | System OK |