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.
Diagnostic Aids
BCM detects that ignition is on and send appropriate power mode message to other modules. BCM must be connected to DLC for any other module to communicate with scan tool. When class 2 serial data circuit is shorted to ground, DTC U1300 or U1305 will be set. If DTC U1300 or U1305 is present, go to DTC U1300: CLASS 2 DATA LINK SHORTED TO GROUND . When class 2 serial data circuit is shorted to power, DTC U1301 or U1305 will be set. If DTC U1301 or U1305 is present, go to DTC U1301: CLASS 2 DATA LINK SHORTED TO POWER .
NO RELATED
Use the Manual With the Right Hardware
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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.