Automatic gearbox - Jatco (Main Relay): Description and operation
- Make
- Land Rover
- Model
- Freelander System Description and Operation (UK)
- Section
- Description and operation › Main Relay
| Pin No. | Description | Input/Output |
|---|---|---|
| 38 | Earth | Input |
| 39 | Fluid temperature sensor | Input |
| 40 | Not used | - |
| 41 | Sport / Manual hold switch | Input |
| 42 | Not used | - |
| 43 | Brake switch signal | Input |
| 44 | Not used | - |
| 45 | Selector 4th range switch | Input |
| 46 | Not used | - |
| 47 | Not used | - |
| 48 | Shift lock solenoid fault | Input |
| 49 | Cruise control engaged signal | Input |
| 50 | Shift lock solenoid earth | Input |
| 51 | Not used | - |
| 52 | Shift solenoid valve C | Output |
| 53 | Low clutch timing solenoid valve | Output |
| 54 | 12V battery voltage from main relay | Input |
Main Relay
The main relay is located in the engine compartment fusebox and supplies battery voltage to the EAT ECU, in addition to other vehicle components. The main relay is energised by the ECM when the ignition is switched on.
When the ignition is switched off, the ECM will maintain the main relay in an energised state for several minutes. This allows for cooling fan operation to continue after the engine has been switched off and allows other vehicle ECU's to remain active. The EAT ECU remains active for a short period after the ignition is switched off to allow EEPROM fault code data to be stored.
In the event of a main relay failure, any of the following symptoms may be observed: l The gearbox will be locked in 4th gear (limp home mode) l No CAN communications will be available.
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