Rear Left Door Ajar Switch Circuit High
The rear left door ajar switch circuit is reporting a high signal.
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What it means (plain English)
The computer thinks the rear left door is always open because it's getting too much voltage from the switch, usually above 4.5 volts when it shouldn't.
What the computer is actually seeing
The Body Control Module (BCM) reads the voltage from the rear left door ajar switch circuit. A normal closed switch should send around 0 volts (or close to it), and an open switch would typically be around 5 volts. This code indicates that the voltage is too high for a closed state.
What a healthy reading looks like
Normal closed switch voltage should be less than 1 volt; open switch at 5 volts.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the wiring and connectors at the rear left door. Look for frayed wires or corrosion.
- 22. Measure the voltage at the door ajar switch connector. It should be below 1 volt when closed and near 5 volts when open.
- 33. If the voltage is above 4.5 volts with the door closed, replace the rear left door ajar switch and retest.
- 44. If replacing the switch does not clear the code, check for short circuits in the wire harness.
- 55. If no physical damage is found and switch is good, test or replace the Body Control Module (BCM).
Common causes
- Faulty rear left door ajar switch
- Damaged wiring or connectors in the door circuit
- Short to voltage in the door ajar switch circuit
- Faulty Body Control Module (BCM)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but your door warning light may be on, and you won't know if a door is actually ajar.
Will this code come back after clearing?
If the issue isn't fixed, yes, the code will return.
Why do I see this code with B2605?
These codes often appear together because they relate to the same door's switches and circuits.
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