Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC U2004: Transmitted SPI Data Output Low: Description
DTC U2004 indicates that BFC has detected a short to ground or open on SPI data line from instrument cluster to BFC. DTC U2004 will set when Ignition 0 is active, and when first data byte transmitted to instrument cluster does not have feedback for 64 transmission cycles.
When DTC U2004 is set, THEFT SYSTEM, ABS, and SERVICE VEHICLE SOON indicators will illuminate, fuel and temperature gauges will read zero, and PRNDL indicator will be blank. DTC U2004 can be cleared using scan tool, or history DTC will disappear after 100 ignition cycles if fault conditions do not reoccur.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.