Specifications Test connector, diagnosis (15) Located in junction box, centrally on one side of the en- gine. Connector ........................................................... 2 pin TWD740VE TWD1231VE Fuse (13) Circuit breaker........................................................ 8 A TWD740VE TWD1231VE Coolant temperature sensor (12) Type: Thermistor with negative temperature coefficient, so-called NTC resistor. Measurement range ........................ –30° C to +120° C Charge air temperature sensor (21) Type: Thermistor with negative temperature coefficient, so-called NTC resistor. Measurement range .........................
-40° C to +150° C 12 41 Code Meaning Reason Reaction Action – Erase fault code. Faulty internal voltages in the control unit. 8.1 Control unit 8.2 Control unit - internal sensors If the charge air pressure is unreasonable, Unreasonable values of fuel tempera- Erase fault code. the system will assume a charge air ture, charge air pressure or the positive pressure as a function of engine speed. supply voltage inside the control unit is This can lead to reduced performance and too low. increased exhaust smoke. If the fuel temperature is unreasonable, the system will assume that the fuel temperature is 40°C. If the true temperature is lower, there is a risk of excessive power delivery.
Higher true temperature causes somewhat reduced performance. – Internal fault in control unit. 8.3 Read/write fault in control Erase fault code. Re-calibrate linkage. calibration. – Control unit – Storage memory Erase fault code. The control unit suffers read/write 8.4 faults when reading from/writing to the 8.5 internal memory. 8.6 Internal fault in program memory. – Erasing fault code. Disconnect the EDC system 9.9 Control unit – Program memory from system voltage for 5 minutes. Excessive coolant temperature If the coolant temperature is too high, the Other Warning lamp on instrument panel Check the cooling system alarms for high coolant temperature.
system will reduce the amount of fuel injected until the temperature is normalised