Pin Voltage Charts
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2002 BMW Z3, 2002 BMW M Roadster, 2002 BMW M Coupe, 2001 BMW Z3, and 2001 BMW M Roadster. However, it is still accessible from the selected car via links, so may be relevant.
Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the A/C-heater control unit determines whether it is receiving and transmitting proper voltage signals. See the following A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS tables.
NOTE:
All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with minimum 10-megohm input impedance.
A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (Z3 - BLACK 8-PIN CONNECTOR X18349)
| Pin No. | Function/Description | Signal Type | Connection |
|---|---|---|---|
| 1 | Terminal 15 | Input Signal | Heating Blower Relay |
| 2 | Activate Compressor Clutch | Output Signal | Instrument Cluster |
| 3 | Bower Level 1 (Air Conditioning) | Output Signal | Blower Resistor |
| 4 | Terminal 15 | Input Signal | Heating Blower Relay |
| 5 | Bower Level 1 (Air-Recirculation) | Output Signal | Blower Resistor |
| 6 | Ground For Function Lights | Ground | Ground Point |
| 7 | Terminal 15 | Input Signal | Heating Blower Relay |
| 8 | Activate Fresh Air-Recirculation | Output Signal | Fresh Air-Recirculation Motor |
A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (Z3 - BLACK 6-PIN CONNECTOR X18350)
| Pin No. (1) | Function/Description | Signal Type | Connection | ||
|---|---|---|---|---|---|
| 2 | Ground | Ground Circuit | Ground Point | ||
| 3 | Climate-On-Signal | Input Signal | Air Conditioning/Recirculated Air Operating Unit | ||
| 5 | Activate A/C Compressor | Output Signal | Pressure Switch | ||
| 6 | Evaporator Temperature | Input Signal | Evaporator Temperature Sensor | ||
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A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (M VEHICLES - BLACK 8-PIN CONNECTOR X18349)
| Pin No. | Function/Description | Signal Type | Connection |
|---|---|---|---|
| 1 | Ground | Ground Circuit | Ground Point |
| 2 | A/C-On-Signal | Output Signal | Evaporator Controller |
| 3 | A/C-On-Signal | Output Signal | Normal Speed Relay |
| 4 | Terminal 15 | Input Signal | Heating Blower Relay |
| 5 | Blower Level 1 (Air Recirculation) | Output Signal | Blower Resistor |
| 6 | Function Light Ground | Ground Circuit | Ground Point |
| 7 | Terminal 15 | Input Signal | Heating Blower Relay |
| 8 | Activate Fresh Air-Recirculation | Output Signal | Fresh Air-Recirculation Motor |
A/C-HEATER CONTROL UNIT PIN ASSIGNMENTS (M VEHICLES - BLACK 6-PIN CONNECTOR X18350)
| Pin No. (1) | Function/Description | Signal Type | Connection | ||
|---|---|---|---|---|---|
| 2 | Ground | Ground Circuit | Ground Point | ||
| 3 | Climate-On-Signal | Input Signal | Air Conditioning/Recirculated Air Operating Unit | ||
| 5 | Activate A/C Compressor | Output Signal | Pressure Switch | ||
| 6 | Evaporator Temperature | Input Signal | Evaporator Temperature Sensor | ||
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