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.
Normal Operation
The passive anti-theft system (PATS) transceiver receives voltage from the central junction box (CJB) fuse 28 (5A) on circuit 1266 (RD/YE) and is grounded on circuit 875 (BK/LB). The PATS transceiver and the powertrain control module (PCM) communicate on circuits 1215 (WH/LG) and 1216 (GY/OG). The PCM compares the key code stored in memory and enables the starter if the key code is correct.
DTC B1681 - sets when the PATS transceiver signal is not received by the PCM. This DTC can be caused by circuits to the PATS transceiver, circuits between the PATS transceiver and the PCM, the PATS transceiver or the PCM. This can also be caused by using the incorrect PATS transceiver part number.
Possible Causes
- Fuse
- Circuit 875 (BK/LB) open
- Circuit 1215 (WH/LG) open, short to ground or voltage
- Circuit 1216 (GY/OG) open, short to ground
- Circuit 1266 (RD/YE) open
- PATS transceiver
- PCM
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.