How to Test an Engine Computer in a 1996 Volkswagen Cabrio
- 1). Locate definitions for all OBD-II diagnostics codes before you even look at your Cabrio. You will find generic, all-vehicle OBD-II coding definitions in your scanner's manua, as well as Volkswagen's distinctive OBD-II codes. They will not appear in the Cabrio's manual, but you can find them in a Haynes Repair Manual for the 1996 Cabrio. You can also find Volkswagen's codes online (see the link in the Resources section).
- 2). Sift through both the generic and Volkswagen's OBD-II codes. Search through only codes that start with the letter "P." For the moment, you can safely ignore anything that starts with a different letter. Read through each of the definitions, and highlight or underline all codes that deal with PCM issues.
- 3). Walk to your Cabrio, and place the materials compiled in steps 1 and 2 on top of the dashboard.
- 4). Pull the ashtray out from the center control panel. Behind it and an access cover, you will find Cabrio's Data Link Connector. The DLC provides your entryway into the vehicle's PCM. Connect your OBD-II scanner to this port.
- 5). Place your key into the Cabrio's ignition, and switch it to the "On" position. Your exact brand of scanner may also require you to start the motor.
- 6). Key in a "Read," "Scan" or "Retrieve" command if OBD-II codes do not immediately appear on your scanner's screen. Since OBD-II scanners operationally differ by brand, consult your device's handbook for the precise steps on how to do this.
- 7). Scroll through the codes on the scanner. As in Step 2, ignore any codes that do not begin with "P." Consult the materials you left onto of the Cabrio's dash, and look for codes that deal directly with the Cabrio's PCM. If you do not find any of these codes, your PCM is fine and not in need of any maintenance. If you do find PCM-related codes, you may need to either reprogram the module or have it replaced.
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