Driver Seat Adjustment Switch Input Circuit Low
There’s a fault in the driver seat adjustment switch circuit indicating a low input.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The seat adjustment switch is designed to send a signal to the computer about your seat position. If the signal is weak or missing, the computer thinks there's a problem, which can happen due to wiring issues or a bad switch.
What the computer is actually seeing
The seat adjustment switch should send a voltage signal, typically between 0.5V (for no adjustment) and 4.5V (for maximum adjustment), to the body control module (BCM) when it's used. A reading lower than 0.5V can trigger the B1538 code.
What a healthy reading looks like
Expected voltage from the seat switch is between 0.5V to 4.5V depending on the position. Any value outside this range, especially lower than 0.5V, indicates a fault.
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. Inspect the wiring and connectors from the driver seat switch to the BCM for any visible damage or corrosion. If damaged, repair or replace as necessary. Decision: If wiring is good, go to step 2; if not, fix the wiring and retest.
- 22. Check the voltage at the seat adjustment switch with a multimeter while operating the switch. Expect readings between 0.5V and 4.5V. Decision: If you see proper voltage, the issue may be with the BCM; if not, replace the switch and retest.
- 33. If the switch is replaced and the issue persists, test the BCM for fault codes or failures. Verify proper operation of the BCM. Decision: Replace the BCM if it's confirmed faulty.
Common causes
- Faulty seat adjustment switch
- Damaged wiring or connectors in the circuit
- Corroded connectors
- Faulty body control module (BCM)
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
Yes, it's safe to drive, but the seat adjustment may not work, affecting comfort and visibility.
Will this code come back after clearing?
If the underlying issue isn’t fixed (like a faulty switch or wiring), the code will likely return.
Why does it pair with other codes like B1536?
Codes like B1536 often indicate issues with related components, such as other seat controls or switches.
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