P1593

P1593
Intake Manifold Length Tuning 2 (Cylinders 4 - 6) - Open-Circuit

P1594
Intake Manifold Length Tuning 2 (Cylinders 4 - 6) - Short Circuit to Ground

P1595
Intake Manifold Length Tuning 2 (Cylinders 4 - 6) - Short Circuit to B+

Function
Intake manifold length tuning serves to increase the torque in a certain speed/load range.

Diagnosis conditions
A fault is detected and stored in the memory if the engine speed is above 80 1/min and if the battery voltage is between 7.5 Volt and 17 Volt.





Wiring diagram

Diagnostic procedure





DTC P1593





P1594





P1595

Check change-over valve.
1. Remove connector at changeover valve.
2. Connect ohmmeter between changeover valve pins 1 and 2.
- Display: 25 - 35 ohms at 20°C

Check wiring from ECM pin 35 to change-over valve for discontinuity.
1. Remove connector at ECM.
2. Remove connector at changeover valve.
3. Connect ohmmeter between ECM pin 35 and changeover valve connector pin 1.
- Display: 0 - 5 ohms
- If infinite resistance is displayed, check connector X 60 pin 18 and check wiring harness for trapped locations and abrasions.

Check wiring from ECM pin 35 to change-over valve for short circuit to ground.
1. Remove connector at ECM.
2. Remove connector at changeover valve.
3. Connect ohmmeter between ECM connector pin 35 and ground.
- Display: infinite resistance
- If 0 - 5 ohms is displayed, check wiring harness for trapped locations and abrasions.

Check wiring from ECM pin 35 to change-over valve for short circuit to B+.
1. Remove connector at ECM.
2. Remove connector at changeover valve.
3. Connect voltmeter to ECM connector pin 35 and ground.
4. Switch on ignition. Display: 0 Volt
- Check wiring harness for trapped locations and abrasions if battery voltage is displayed.