ESP Description

ABS/EDL/ASR/ESP ITT Mark 20 IE

The Electronic Stabilization Program (ESP) is a driving dynamics regulation system. It stabilizes the vehicle both in understeer and oversteer situations. ESP works throughout the entire speed range. When ESP is in regulation mode, the ESP indicator lamp blinks 3 times per second.

ESP is an additional extension of the well-known driving safety system ABS/EDL/ASR.

ESP increases controllability of the vehicle during critical driving situations. It reduces the likelihood of skidding relative to the well-known safety systems and improves steering control.

Function

The ABS control module, the steering angle sensor, the Transmission Control Module (TCM) and the Engine Control Module (ECM) etc. are connected to each other via a dataBUS wire. Therefore, the DTC memories of all control modules installed in the vehicle must be checked via the button combo -0- -0-, "Automatic test sequence", at the beginning of every troubleshooting procedure. If other control modules have DTCs stored, use the DTC table to determine whether these malfunctions could be influencing the ABS system.

The On Board Diagnostic (OBD) function relates to the electrical and electronic parts of the ABS system; i.e. it can only recognize malfunctions via the electrical connection to the control module (e.g. interruption of a wheel speed sensor).

The 47-pin ABS control module (w/EDL) -J104- forms a compact unit with the hydraulic unit. The unit is located on the left-hand side of the engine compartment. The control module is equipped with DTC memory. The vehicle's Data Link Connector (DLC) is located in the instrument panel below the driver-side storage compartment.

The control module recognizes malfunctions during vehicle operation and saves DTCs in permanent memory; this information is retained even when battery voltage fails.

If a stored malfunction does not occur again after re-starting vehicle and completing a driving cycle (speed >20 km/h) then this malfunction will be indicated as sporadic (temporary). If such a malfunction does not occur again within 50 vehicle starts and driving procedures, it will be erased from DTC memory, except for the malfunction "control module faulty". (malfunction removal counter).

Malfunctions affecting the data-BUS system are already erased after 15 vehicle starts and driving cycles if they have been recognized as sporadic.

After ignition is switched on, the ABS warning light -K47-, the red warning light for brake system -K118- , and the ESP control lamp -K155- light up for approx. 2 seconds.

A test sequence (self-test) is performed in the control module during this time, with the following functions:
- Supply voltage is tested, min. 10.0 volts
- Control module and valve coils are checked
- A wheel speed sensor test (electrical) is performed that is not completed until 20 km/h has been reached
- The control module coding is checked

Additional information for All Wheel Drive (AWD) vehicles with Haldex coupling
The longitudinal acceleration sensor -G251- must be switched off before checking brake system on a dynamometer.
Switch ignition off and on again one time to re-activate the longitudinal acceleration sensor -G251-.
All Wheel Drive (AWD) vehicles with Haldex coupling are equipped with "Electronic Differential Lock" (EDL).