P1849

DIAGNOSTIC TROUBLE CODES P1847, P1848 AND P1849
PRESSURE CONTROL SOLENOID, PRESS CTRL SOLENOID, OUTPUT TOO LOW OR TOO HIGH, SHORT CIRCUIT TO GROUND OR TO BATTERY POSITIVE VOLTAGE AND OPEN CIRCUIT OR SHORT CIRCUIT IN VALVE

Fault Symptom.
Warning lamp CHECK GEARBOX lit. The system's emergency program is activated.

Conditions.
Diagnostic trouble code P1847 is recorded if there is an open circuit or short circuit to ground in the circuit to the pressure control solenoid.

Diagnostic trouble code P1848 is recorded if there is a short circuit to battery voltage in the circuit to the pressure control solenoid.

Diagnostic trouble code P1849 is recorded if there is a short circuit in the circuit - internally in the solenoid or between feeder cables - to the pressure control solenoid.

The condition requires that the engine is running. The pressure control solenoid controls the fluid pressure in the transmission. The solenoid is controlled by a varying current from the Transmission Control Module (TCM). If there is a short circuit to ground or an open circuit, the system pressure becomes too high. This results in hard gear-shifting and the lock-up function not operating.

If there is a short circuit to battery voltage, the system pressure becomes low. This results in high wear.

Diagnostic Procedure.
1. Connect ISAT scan tool to the car's data link connector. Activate the pressure control solenoid by initiating PRESS CTRL SOLENOID in ISAT menu ACTIVATE. The solenoid is activated by 2 currents (910 mA and 250 mA) alternately. Listen for a clicking sound in the solenoid. You might have to use a stethoscope.

If the solenoid clicks, go to step 9.

If the solenoid does not click, go to step 2.





2. If you are not quite sure, continue with ISAT scan tool connected as follows:
- Engine idling,
- Handbrake applied hard,
- Selector lever in position D.

Activate PRESS CTRL SOLENOID in ISAT menu READ FUNCTIONS. Nominal value is about 900 mA/ 3.4 - 4.6 bar at idling. Depress the accelerator pedal and record the change in the value.

If the measurement result is correct, go to step 9.

If the measurement result is wrong, go to step 3.

3. With the ignition switched OFF, disconnect connector H10-3 located behind the battery in the engine compartment (grey 10-pin Packard connector). Carry on with continuity measuring. Connect an ohm meter between pins 5 and 6 in the TCM (female). Nominal resistance is 2 - 6 ohms.

If the measurement result is correct, go to step 7.

If the measurement result is wrong, go to step 4.

4. With the ignition switched OFF, disconnect the connector to the solenoid, 531, on the transmission (8-pin Packard connector).
Connect an ohm meter between pins 6 and 7 (male). Nominal resistance is 2 - 6 ohms.

If the ohm meter shows the correct value, go to step 5.

If the ohm meter shows a different value, check the connectors and the wiring to the solenoid valve and remedy any faults.

If the fault remains, install a new valve unit.





5. With the ignition switched OFF, carry out continuity measuring of the wiring between connectors 531 and H10-3.
Connect an ohm meter between:
- connector H10-3 pin 5 (female) and connector 531 pin 6 (female).
- connector H10-3 pin 6 (female) and connector 531 pin 7 (female).

Nominal resistance is <1 ohm.

If the measurement result is correct, go to step 6.

If the measurement result is wrong, check the connectors and the wiring between them and remedy any faults.

6. Check connector H10-3 for slide-outs and remedy any faults.

Go to step 9.

7. With the ignition switched OFF, connect a BOB between the TCM and the wiring.

Carry out continuity measuring. Connect an ohm meter between:
- connector pin 16 and connector H10-3 pin 5 (male).
- connector pin 34 and connector H10-3 pin 6 (male).

Nominal resistance is <1 ohm.

If the measurement result is correct, go to step 8.

If the measurement result is wrong, check the connectors and the wiring and remedy any faults.





8. Connect a BOB to the TCM. Carry out voltage measuring. Connect a voltmeter between pins 16 and 34. Activate the pressure control solenoid by activating PRESS CTRL SOLENOID in ISAT menu ACTIVATE.

Measuring conditions:
- engine idling,
- hand brake applied hard,
- selector lever in position D.

Nominal value about 0.7 V and 4.3 V in the two valve currents during the activation.

If the measurement result is correct, go to step 9.

If the measurement result is wrong, go to "Actions Before Changing a TCM".

9. Clear the diagnostic trouble code start and test drive the car and check if the diagnostic trouble code reappears.

If a trouble code is recorded, go to "Actions Before Changing a TCM".