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.
1988 Cadillac Seville BaseFACTORY OEM SERVICE PROCEDURE
BCM Trouble Code Identification
BCM TROUBLE CODE IDENTIFICATION
| Code | Circuit Affected |
|---|---|
| B110 | Outside Temperature Sensor circuit |
| B111 | A/C High Side Temperature Sensor Circuit |
| B112 | A/C Low Side Temperature Sensor Circuit |
| B113 | In-Car Temperature Sensor Circuit |
| B115 | Sunload Temperature Sensor Circuit |
| B119 | Twilight Photocell Circuit |
| B120 | Twilight Delay Pot Circuit |
| B121 | Twilight Enable Switch |
| B122 | Panel Light Dimming Pot Circuit |
| B123 | Courtesy Light Switch |
| B124 | Vehicle Speed Sensor (VSS) |
| B127 | PRND321 Sensor |
| B334 | Loss Of ECM Data |
| B335 | Loss Of CCDIC Data |
| B336 | Loss Of IPC Data |
| B337 | Loss Of A/C-Heater Programmer Data |
| B410 | Charging System Circuit |
| B411 | Battery Voltage Low |
| B412 | Battery Voltage High |
| B420 | Relay Circuits |
| B440 | A/C-Heater System Air Mixture Door |
| B441 | Cooling Fans Problem |
| B446 | Low Refrigerant Pressure |
| B447 | Low Refrigerant Pressure |
| B448 | Low Refrigerant Pressure |
| B449 | A/C High Side Temperature |
| B450 | High Coolant Temperature |
| B552 | Keep Alive Memory Error |
| B556 | Odometer EEPROM Error |
Factory Service Tools
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.