Powertrain Control Module

WARNING: This page is about a different car, the 2018 Land Rover Discovery Sport. However, it is still accessible from the selected car via links, so may be relevant.

The Powertrain Control Module (PCM) is located at the rear of the engine compartment, between the bulkhead panel and the engine sound insulation.

The PCM receives inputs from various sensors and output reference voltages and signal information to other sensors for engine control.

The PCM receives inputs from the following:

Anti-lock Brake System (ABS) control module

Crankshaft Position (CKP) sensor

Camshaft Position (CMP) sensor (2 off)

Brake pedal switch

Transmission Control Module (TCM)

Transmission Control Switch (TCS)

Ambient Air Temperature (AAT) sensor

Radiator outlet Engine Coolant Temperature (ECT) sensor

Engine cooling fan control module

Heated Oxygen Sensor (HO2S) (3 off)

Variable Camshaft Timing (VCT) solenoid (2 off)

Mass Air Flow and Temperature (MAFT) sensor

Electric throttle - Throttle Position Sensor (TPS)

Cylinder head temperature sensor

Cylinder block temperature sensor

Knock sensor (2 off)

Oil pressure and temperature sensor

Oil pump control solenoid

Variable coolant pump - Shroud position

Manifold Absolute Pressure and Temperature (MAPT) sensor

Engine Coolant Temperature (ECT) sensor - Electric thermostat housing

Engine coolant level sensor

Flex Fuel Sensor (FFS) - Brazil market only

Continuously variable valve lift assembly oil temperature sensor

Fuel Rail Pressure and Temperature (FRPT) sensor

Restraints Control Module (RCM)

Accelerator Pedal Position (APP) sensor.

The PCM provides outputs to the following:

Electric Throttle

Fuel injector (4 off)

Ignition coil (4 off)

Variable Camshaft Timing (VCT) solenoid (2 off)

Purge valve

Engine cooling fan control module

Charge air coolant pump

High Pressure (HP) fuel pump

Fuel Pump Driver Module (FPDM)

Compressor Recirculation Valve (CRV)

Turbocharger wastegate actuator

Heater element - Electric thermostat housing

Auxiliary coolant pump

Diagnostic Module Tank Leakage (DMTL) - North American Specification (NAS) vehicles only

Variable coolant pump

Piston cooling oil jets solenoid

Active exhaust actuator

Continuously variable valve lift solenoid (4 off).

The PCM is connected to the vehicle harnesses via two connectors. The PCM contains data processors and memory microchips. The output signals to the actuators and sensors are in the form of ground paths provided by driver circuits within the PCM. The PCM driver circuits produce heat during normal operation. Cooling for the PCM is provided by a ribbed casing and a cooling fan assembly.

The PCM performs self-diagnostic routines and stores Diagnostic Trouble Codes (DTCs) in its memory. These DTCs and diagnostics can be accessed using a Jaguar Land Rover approved diagnostic equipment. If the PCM is to be replaced, the new PCM is supplied 'blank' and must be configured to the vehicle using a Jaguar Land Rover approved diagnostic equipment. A 'flash' Electrically Erasable Programmable Read Only Memory (EEPROM) allows the PCM to be externally configured, with market specific or new tune information. The current engine tune data can be accessed and read using a Jaguar Land Rover approved diagnostic equipment.

The PCM is connected to the engine sensors which allow it to monitor the engine operating conditions. The PCM processes these signals and determines the actions necessary to maintain optimum engine performance in terms of driveability, fuel efficiency and exhaust emissions. The memory of the PCM is programed with instructions for how to control the engine, this known as the strategy. The memory also contains data in the form of maps which the PCM uses as a basis for fueling and emission control. By comparing the information from the sensors to the data in the maps, the PCM is able to calculate the various output requirements. The PCM contains an adaptive strategy which updates the system when components vary due to production tolerances or ageing.

Some sensors receive a regulated voltage supplied by the PCM. This avoids incorrect signals caused by voltage drop during cranking.

The PCM receives a vehicle speed signal on the High Speed (HS) Controller Area Network (CAN) powertrain systems bus from the Anti-lock Brake System (ABS) control module. Vehicle speed is an important input to the PCM strategies. The ABS control module derives the speed signal from the wheel speed sensors. The frequency of this signal changes according to road speed.

The PCM uses this signal to determine the following:

When to permit speed control operation.

To control the operation of the speed control system.

Implementation of the idle strategy when the vehicle is stationary.