Vehicle Speed Signal Missing
The computer is not receiving a vehicle speed signal from the transmission or ABS module.
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 engine control module (ECM) expects to see a vehicle speed signal, usually sent from the transmission control module or the ABS, but it's not getting any data, meaning it's unsure how fast the vehicle is moving.
What the computer is actually seeing
The ECM sees no input from the speed sensors, which normally output a voltage signal (0-5 volts). If the signal is completely missing, the ECM flags this code.
What a healthy reading looks like
Typically expects a consistent signal corresponding to vehicle speed—ideally, 0-5 volts that vary based on speed (e.g., 2.5 volts at 30 mph).
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 vehicle speed sensor wiring for damage, corrosion, or loose connections. Decision: If damaged, repair/replace wiring and retest. If not, proceed to step 2.
- 22. Test the output of the vehicle speed sensor with a multimeter. Expected output is 0-5 volts when the vehicle is moving. Decision: If output is present and correct, suspect wiring to the ECM; if not, replace the VSS and retest.
- 33. If the VSS is replaced and the issue persists, check the ABS module operation or connectors. Decision: If ABS module is not reading correctly, it may need replacement; if wiring is fine, check ECM for faults.
Common causes
- Faulty vehicle speed sensor (VSS)
- Open or shorted wiring in the speed sensor circuit
- Faulty ABS module
- Corroded connectors
- ECM failure
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but not recommended for long distances; no accurate speed readings can affect cruise control and stability systems.
Will this code come back after repairs?
If the underlying issue is fixed correctly, it should not come back.
Why does this code sometimes pair with ABS codes?
Both systems rely on similar speed readings; a fault in one system may cause issues in the other.
Working a real vehicle right now?
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