P1857

GEAR SHIFTING SOLENOID VALVE, SOLENOID 2-3 (S2), SHORTED TO GROUND (P1857) OR OPEN CIRCUIT/SHORTED TO B+ (P1858).





Fault Symptom.
CHECK GEARBOX indicator lamp on.
The system's emergency operation program has been activated.
P1857: Gear shifting not possible.
P1858: Gear shifting is not possible with solenoid S2 and the transmission operates only in 4th gear.

Conditions.
P1857: Short-circuit to ground when the solenoid is activated. The solenoid is activated in gear positions P, R and N or if the car is driven in 1st or 2nd gear with the selector lever in position D or 3.
P1858: Short circuit to battery positive (B+) or open circuit when the solenoid is not activated. The solenoid is not activated if the car is driven in 3rd or 4th gear with the selector lever in position D or 3.

Diagnostic Help.
^ Solenoid S2 can be activated by the ISAT scan tool as follows:
Select "ACTIVATE".
Select "SOLENOID 2-3".
The solenoid will be activated for 30 seconds at a frequency of 1 Hz. Listen for the clicking sound.

^ Without using the ISAT scan tool, solenoid S2 can be activated as follows:
Turn the ignition switch to the ON position.
Move the selector lever to position D.
When WINTER mode is selected, the solenoid goes ON (operates) and when WINTER mode is disengaged the solenoid goes OFF (releases). Listen for the clicking sound.





Procedure.
1. Check the resistance of the solenoid valve
Unplug connector H16-3 (16-pin connector located behind the battery). Take a resistance reading across pin 9 of the male connector and a good grounding point on the transmission.
The reading obtained should be 10-20 ohms.

Is the resistance OK?

YES: Proceed to point 3.
NO: Continue with point 2.

2. Check the resistance of the solenoid valve (contd.)

Remove the valve housing cover and the solenoid lead. Check the resistance of the lead between pin 9 of male connector H16-3 and the solenoid.
The resistance should be less than 0.5 ohms.

Is the resistance OK?

YES: Carry out a visual check of the solenoid's electrical connection for moisture and corrosion. If any probable cause of the fault can be seen it should be rectified, otherwise the solenoid should be changed. Then proceed to point 5.
NO: Repair or replace the wiring (including connectors) between connector H16-3 and the solenoid. Then proceed to point 5.




3. Check The Wiring connected to the transmission control module

Check the continuity of the lead between pin 9 of connector H16-3 and pin 3 of the transmission control module's connector. Remember to check for slide-out of connector pins and sockets.

Is the lead OK?

YES: Continue with point 4.
NO: Rectify the fault and proceed to point 5.

4. Check the transmission control module output
- Plug in the transmission control module.
- Connect a test lamp to pin 9 of female connector H16-3 and battery negative (B-).
- Connect the ISAT scan tool.
- Turn the ignition switch to the ON position.
- Select "ACTIVATE".
- Select "SOLENOID 2-3". The test lamp should flash for 30 seconds.

Does the test lamp flash?

YES: Check the solenoid and its electrical connection for moisture and corrosion. If there is no probable cause of the fault, the solenoid should be changed. Then continue with point 5.
NO: Continue with point 5.




5. Final check

Clear the diagnostic trouble code, drive the car on test at varying engine loads and speeds for 5 minutes and obtain readouts of any diagnostic trouble codes that are generated.

Has the diagnostic trouble code recurred ?

YES: Continue as described under "Before Changing A Control Module". Before Changing A Control Module
NO: The remedial action taken was correct.