Technical Description of OBD-II Trouble Code
Malfunction in the Starter Disable Circuit
What does that signify?
This diagnostic trouble code (DTC) is a generic powertrain code that is applicable to many OBD-II vehicles (1996-newer), including Subaru, BMW, Mazda, Volkswagen, Audi, etc. Although it is a generic code, the specific repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
If your vehicle has stored a code P0817, it means that the powertrain control module (PCM) has detected a malfunction in the circuit of the starter disable switch. This code can be relevant to vehicles with manual or automatic transmissions.
The starter disable switch is typically a single circuit, open/closed switch that interrupts the voltage between the ignition switch and the starter solenoid if certain conditions are not met. For manual transmissions, these conditions include the clutch not being depressed and the transmission not being in neutral. For automatic transmissions, the condition is the transmission not being in park. In vehicles with automatic transmissions, the starter disable switch may be integrated into the neutral safety switch or shift selector switch. The ignition position is used by the transmission control module (TCM) or PCM to monitor the voltage of the starter disable circuit. The TCM may be a separate module or part of the PCM.
If the PCM detects that the voltage of the starter disable switch circuit is outside the acceptable range, it may store a code P0817 and illuminate the malfunction indicator lamp (MIL). Multiple ignition cycles with a failure may be necessary for the MIL to illuminate.
What is the severity of this DTC?
A stored code P0817 could result in a no-start condition and indicates that there has been an electrical issue or mechanical failure. It is important to rectify the conditions that led to the storage of this code as soon as possible.
What are some of the symptoms of the code?
Symptoms of a P0817 trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P0817 troubleshooting steps?
To diagnose a code P0817, you will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of vehicle-specific diagnostic information.
You can use your vehicle information source to find a technical service bulletin (TSB) that matches the year, make, and model of your vehicle, as well as the stored codes and exhibited symptoms. If you find a relevant TSB, it can provide helpful diagnostic information.
Connect the scanner to the vehicle diagnostic connector to retrieve all stored codes and freeze frame data. It is recommended to write down this information before clearing the codes and then test-drive the vehicle until the PCM enters readiness mode or the code is reset.
If the PCM enters readiness mode at this point, the code is intermittent and may be more challenging to diagnose. In such cases, the conditions that led to the storage of the code may need to worsen before an accurate diagnosis can be made.
If the code is immediately reset, the next step in your diagnosis will involve consulting your vehicle information source for diagnostic flowcharts, connector pin-out charts, connector face views, and component testing procedures/specifications.
Step 1
Use the DVOM to test the voltage, ground, and signal output at the appropriate starter disable switch. Typical starter disable switch circuits consist of either battery voltage (when activated) or ground (when deactivated).
Step 2
Refer to your vehicle diagnostic information source and use the DVOM to test the starter disable switches as necessary. Replace switches that do not meet the system parameters.
Step 3
If the system switches and circuits are functioning properly, use the DVOM to test the starter disable switch circuits to the starter and the PCM. Disconnect all controllers before using the DVOM for testing.
