Porsche 993: How to Reset Maintenance Light
Even after doing all the repairs possible on your Porsche 993, the maintenance light stays on. Here is how you can reset it to work as it should.
This article applies to the Porsche 993 (1993-1998).
The check engine/maintenance/service light monitors your car's performance, and gives a warning diagnosis when driveline as well as emission components are faulty. At times, when the light is on, it results in poor fuel economy. It may also indicate mechanical faults in the injectors, bad oxygen sensors, spark plugs, cracked hoses and manifolds, a blown up head gasket, uneven air/fuel mixture, loose fuel cap, as well as many other issues. The maintenance engine light may remain on, even after proper repairs have been done on your Porsche 993. When that happens, there could be incompatible components like belts that have been installed on your Porsche 993. This article will touch on the possible sources of why the maintenance light continues to remain on. This article will also guide you in order to reset the maintenance light.
Materials Needed
- Durametric tool
- Fuel injectors (if applicable)
- Fan and alternator belts (if applicable)
- Ignition coils (if applicable)
Step 1 – Reset with a Durametric tool
The maintenance light may continue to send warnings, even after the proper oil change on your 993 has been done. Assuming that is the only mechanical fault, you can stop the light after an oil change by using the Durametric tool.
To use the Durametric tool, plug it into your OBD-II port, and turn the ignition to the "ON" position. Turn on the Durametric and the switch tabs to the "fault memory" section. This will show you what fault codes were triggered, along with an explanation of what each code means. Highlight the codes and select the "erase fault" prompt. This will clear the codes from the ECU's memory. Safely disconnect the Durametric from the car, and cycle the ignition, starting the car. The codes should have cleared.
Step 2 – Replace the fuel injectors
If the fuel injectors are dirty or clogged, the engine misfires due to lack of fuel being delivered for combustion. That causes the maintenance light to come on as an alert to the aforementioned mechanical fault. Cleaning or replacing the worn out fuel injectors stops the engine light from coming on. Other symptoms of a faulty fuel injector on the 993 are rough idling, engine power loss, carbon monoxide emissions, and stumbled acceleration.
Step 3 – Install the right belts
Replacing the 993 fan and alternator belts with the incorrect belts can cause the maintenance light to come on, and the engine will throw misfire codes. it is suggested to replace worn out belts with original ones from Porsche. It's advisable, before any Porsche 993 engine misfire problem is sorted, to first check if the belts installed are Porsche branded. That saves you from replacing pricey Porsche 993 components that are still in working condition. Yet, if the problem is with the belts, it will cost cost around $100 or less to replace.
Step 4 – Change the ignition coils and spark plugs
If the ignition coils are cracked or worn out, the 993's engine misfires, causing the maintenance light to come on. Replacing worn out ignition coils stops the engine misfire codes, and the maintenance light switch from turning on. Misfire codes from faulty or badly connected spark plugs can also cause the maintenance light to switch on. Connecting them properly, and replacing worn out ones will turn off the maintenance light.
Step 5 – Do a hard reset
If your 993 doesn't have the above mechanical faults, but the maintenance light keeps blinking, then do a hard reset. This involves disconnecting the battery to drain power from the on board diagnostics, which save the fault codes. To drain all the power, leave the lights on after disconnecting the battery. Then, after around an hour or more, the fault codes will be totally erased.
Related Discussions
- Using Durametric Tool - Rennlist.com
- Check Engine Light On - Rennlist.com
