Subject:
Clamp Codes:
In the electrical installations in automotive technology, clamp codes are established. This prevents confusion (e.g., abroad) and allows for quicker reading in the diagram (2 digits instead of whole texts). These codes are established in the DIN 72552 standard.
Below is the table of the most common codes:
| a0 | Coil, Distributor |
| 1 | Low Voltage |
| 4 | High Voltage |
| 7 | Control Contact |
| 15 | Switched positive (ignition switch output) |
| 15a | Switched positive after the ballast resistor of coil and starter motor |
| a0 | a0 |
| a0 | Glow Plug Switch (diesel engines) |
| 17 | Starting |
| 19 | Glowing |
| a0 | a0 |
| a0 | Battery |
| 30 | Positive from Battery |
| 31 | Ground of the vehicle / negative terminal battery |
| a0 | a0 |
| a0 | Electric Motors |
| 32 | Return Line |
| 33 | Main Connection |
| 33b | Shunt Field |
| 33L | Rotation Direction Left |
| 33R | Rotation Direction Right |
| a0 | a0 |
| a0 | Flasher Unit (Pulse Generator) |
| 49 | Input |
| 49a | Output flasher unit with time interval |
| 49b | Output, second flasher relay |
| a0 | a0 |
| a0 | Starter Motor |
| 50 | Starter Motor Control (direct) |
| 50a | Battery Changeover Relay Output for Starter Motor Control |
| a0 | a0 |
| a0 | Wiper Motors |
| 53 | Wiper Motor Input (Positive) |
| 53a | Wiper (Positive) End Switch |
| 53b | Wiper, Shunt Windings |
| 53c | Electric Windshield Washer Pump |
| 53e | Wiper, Brake Windings |
| 53i | Wiper Motor with Permanent Magnet and 3rd Brush for Higher Speed |
| a0 | a0 |
| a0 | Lighting |
| 54 | Brake Lights |
| 54G | Rear Fog Light |
| L | Turn Signals Left |
| R | Turn Signals Right |
| 55 | Fog Lamps |
| 56 | Headlights |
| 56a | Main Beam and Indicator Light |
| 56b | Low Beam |
| 56d | Main Beam Signal |
| 57a | Parking Light |
| 57L | Parking Light Left |
| 57R | Parking Light Right |
| 58L | Lighting Left |
| 58R | Lighting Right, incl. Contour and License Plate Light |
| C1, 2 &3 | Turn Signal Indicator 1, 2 &3 |
| a0 | a0 |
| a0 | Generator and Voltage Regulator |
| 61 | Generator Indicator Light |
| B+ | Battery Positive |
| B- | Battery Ground |
| D+ | Generator Positive |
| D- | Generator Negative (Ground) |
| DF (1 & 2) | Generator Field (1 & 2) |
| U, V, W | Three-phase Alternating Current |
| a0 | a0 |
| a0 | Sound Equipment |
| 75 | Radio, Cigarette Lighter |
| 76 | Speaker |
| a0 | a0 |
| a0 | Switch |
| a0 | Disconnect and Changeover Switch: |
| 81 | Input |
| 81a | First Output, Interruptor |
| 81b | Second Output, Interruptor |
| 82 | Input |
| 82a | First Output |
| 82b | Second Output |
| 82y | Second Input |
| 82z | First Input |
| a0 | Multi-step Switch: |
| 83 | Input |
| 83a | Output, Position 1 |
| 83b | Output, Position 2 |
| 83L | Output, Left Position |
| 83R | Output, Right Position |
| a0 | a0 |
| a0 | Switch Relay |
| 85 | Relay Negative Control Current |
| 86 | Relay Positive Control Current |
| 86a | Winding Start or First Winding |
| 86b | Winding Tap or Second Winding Relay Contact |
| 87 | Relay Main Current Connection |
| 87a | Relay Main Current Connection 2 (Changeover or Disconnect Relay) |
| 88b | Normally Open Contact |
| 88 | Relay Contact Input for Disconnect and Changeover Contact |
| 88a | Normally Closed Contact 2 |
| 88b | Normally Open Contact 2 |
| 88c | Third Output |
| a0 | a0 |
| a0 | Extra |
| 52 | Trailer Signal |
| 54g | Solenoid Valves for Trailer Brakes |
| 77 | Door Signal |