Reverse Light Relay Shorted To Battery
Table of contents
B2478 CADILLAC Possible Causes
- Faulty Reverse Light Relay
- Reverse Light Relay harness is open or shorted
- Reverse Light Relay circuit poor electrical connection
- Faulty Platform Zone Module (PZM)
How do I fix code B2478 CADILLAC?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the B2478 CADILLAC code
The cost of diagnosing the B2478 CADILLAC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B2478 CADILLAC Description
When Platform Zone Module (PZM) receives input that transaxle is in Reverse, PZM energizes reverse light relay which will turn on back-up lights. When back-up lights have been commanded on, PZM constantly measures voltage. The Diagnostic Trouble Code (DTC) B2478 will set when voltage is not at ground potential for at least 2 seconds. DTC B2478 will clear when voltage is greater than the ground for at least one monitoring cycle.