The engine module reads a start request – from the ignition switch, a start button via the body module, or start-stop – and drives the starter relay with it. P0512 flags a fault in this signal. Subaru (also in the Saab 9-2X) checks plausibility: if the engine runs above 500 rpm and the start signal stays active for more than 3 minutes, a short or sticking switch is assumed, MIL after two trips. On a Jeep Cherokee diesel a chafed harness caused P0512 with a no-start. The starter then does not crank – or with a short to positive keeps running.
Medium severity. Can I keep driving?If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.
Symptoms
- Engine does not start, starter does not crank
- Starter keeps running after the start (noise)
- Check engine light (Subaru after two trips)
Most likely causes
- Ignition or start switch, or start button, faulty or sticking
- Harness chafed, short to ground or positive
- Selector or clutch switch in the start path
- Starter relay sticking
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of P0512 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 5: Speed and idle
- 12: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0512?
If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.
What causes code P0512?
The most common causes are: ignition or start switch, or start button, faulty or sticking; harness chafed, short to ground or positive; selector or clutch switch in the start path.
Related codes
- P0615Starter Relay A Circuit
- P0616Starter Relay A Circuit Low
- P0617Starter Relay A Circuit High
- P0513Incorrect Immobilizer Key
Sources
- saabwisonline.com: dtc p0512 starter request circuit
- static.nhtsa.gov: MC 10140160 9999
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.