P1817

DIAGNOSTIC TROUBLE CODE P1817
TACHOMETER, TRANSMISSION INPUT SPEED, INPUT TO TCM MISSING

Fault symptom
Warning lamp CHECK GEARBOX lit. The system's emergency program activated. No incoming speed to the transmission results in hard gear shifting and the lock-up function not working very well.

Condition
Signal from input shaft speed sensor missing and car's speed exceeds 4 km/h (2.5 mph).

Diagnostic procedure
1. Connect ISAT scan tool to the car's data link connector. Check incoming transmission rpm by initiating INPUT SPEED on ISAT menu READ FUNCTIONS with the engine running and the selector lever in position P. Press the accelerator pedal and record the measurement results.

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

If the measurement result is wrong, go to step 2.

2. With the ignition switched OFF, disconnect connector H10-1 located behind the battery in the engine compartment (black 10-pin Packard connector). Connect an ohm meter between pins 10 and 9 (female). Nominal resistance is 300 - 600 ohms.

If the ohm meter shows the correct value, go to step 6.

If the ohm meter shows a different value, go to step 3.





3. With the ignition switched OFF, disconnect the connector to the Input Shaft Speed (ISS) sensor, 532, on the transmission (black 2-pin Packard connector). Connect an ohm meter between pins 1 and 2 (female). Nominal resistance is 300 - 600 ohms.

If the ohm meter shows the correct value, go to step 4.

If the ohm meter shows the wrong value, check the connector and the wiring to the ISS sensor and remedy any faults.

If you cannot find any faults, install a new ISS sensor.

4. With the ignition switched OFF, carry out continuity measuring of the wiring between:
^ connector H10-1 pin 10 (male) and connector 532 pin 2 (male),
^ connector H10-1 pin 9 (male) and connector 532 pin 1 (male).

Nominal resistance is <1 ohm.

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 between them and remedy any faults.

5. Check connector H10-1 for slide-outs and remedy any faults.

Then go to step 8.





6. With the ignition switched OFF, connect a BOB between the Transmission Control Module (TCM) and the wiring. Connect an ohm meter between pins 12 and 31. Nominal resistance is 300 - 600 ohms.

If the ohm meter shows the correct value, go to step 7.

If the ohm meter shows a different value, check the connectors and the wiring between them and remedy any faults:
^ H10-1 pin 10 (male) - pin 12,
^ H10-1 pin 9 (male) - pin 31.

7. Check incoming speed by initiating INPUT SPEED in ISAT menu READ FUNCTIONS with the engine running and selector lever in position P.

Check pin 12 at the same time with pulse measuring, reference step pin 31.
Nominal value:
^ Idling: 1.2-1.4 V (approx.), 160-200 Hz.
^ 2500 rpm: 2.2 V (approx.), 500 Hz.

If ISAT and the pulse measuring show correct values, go to step 8.

If ISAT and the pulse measuring show different values, go to "Actions Before Changing a TCM".

8. Clear the diagnostic trouble code, start and test drive the car and check if the trouble code reappears. If a trouble code is recorded, go to "Actions Before Changing a TCM".