GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 CTS 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Engine Controls Schematics
Figure 1:

Power, Ground, Serial Data, and MIL
Object Number: 866172 Size: FS
Figure 2:

Underhood Fuse Block Main Relay 1 of 2
Object Number: 866228 Size: FS
Figure 3:

Underhood Fuse Block Main Relay 2 of 2
Object Number: 866232 Size: FS
Figure 4:

5 Volt and Low References
Object Number: 821462 Size: FS
Figure 5:

Extended Travel Brake Switch, ECT and MAF/IAT Sensors
Object Number: 866233 Size: FS
Figure 6:

Engine Data Sensors - Oxygen Sensors
Object Number: 866237 Size: FS
Figure 7:

Engine Data Sensors - Electronic Throttle Controls
Object Number: 843484 Size: FS
Figure 8:

Engine Data Sensors - CKP, CMP, and KS Sensors
Object Number: 821469 Size: FS
Figure 9:

Ignition Coils
Object Number: 821468 Size: FS
Figure 10:

Fuel Injectors, Fuel Pump Relay, and Fuel Pump/Sender Assembly
Object Number: 821471 Size: FS
Figure 11:

Fuel Controls - EVAP Controls
Object Number: 821472 Size: FS
Figure 12:

Controlled/Monitored Sub-System References
Object Number: 821473 Size: FS