Scan Tool Communication Error
If scan tool will not communicate with PCM (no response on scan tool) or will not respond to a particular request, a communication error exists. A communication error could be caused by the following:
- Operator error.
- Vehicle wiring.
- DLC terminals damaged.
- PCM malfunction.
- Low battery voltage.
The scan tool may display a 2-digit code indicating communication status. These codes are communication status codes, not DTCs. Some status codes indicate normal communication function. See the SCAN TOOL COMMUNICATION CODES table. If scan tool displays a system okay code (Code 62) after performing QUICK TEST , proceed to the TESTS W/O CODES article for symptom diagnosis. If scan tool indicates a communication error (e.g., Code 10), go to CIRCUIT TEST QA for diagnostic procedure.
SCAN TOOL COMMUNICATION CODES
| Code | Description | Definition |
|---|---|---|
| 00 | General Affirmative | PCM Received A Valid Request From Scan Tool |
| 10 | General Reject | PCM Will Not Respond |
| 11 | Mode Not Supported | PCM Is Not Capable Of Performing A Requested Test |
| 12 | Invalid Data Format | An Unrecognized Character Is Inserted Into A String Of Data |
| 21 | PCM Is Busy At Time Of Request | PCM Is Already Performing A At Time Another Test Is Being Requested |
| 22 | Entry Conditions Not Correct | Usually Operator Error (i.e., Engine Not Running, Etc.) |
| 23 | Results Not Done | Request Received, But PCM Is Not Ready To Respond |
| 50 | Upload Not Accepted | Request Cannot Be Accomplished Due To Fault Condition |
| 61 | Normal Exit With Results | PCM Completed A Valid Request (Test) & A DTC Was Recorded |
| 62 | Normal Exit No Results | PCM Completed A Valid Request & No DTC Recorded |
| 63 | Abnormal Exit With Results | While Performing Test, Error Occurred, But PCM Has Results |
| 64 | Abnormal Exit Without Results | While Performing Test, Error Occurred And No Results Are Available |