P1810

Circuit Description
The automatic transmission fluid pressure (TFP) manual valve position switch consists of six pressure switches (three normally-closed and three normally-open switches). Ignition voltage is applied to each of the switches. By grounding or opening one or more of these switches with fluid pressure from the manual valve, the PCM can detect which gear range is selected.
If the PCM detects an illegal combination on any range inputs (ON/OFF/ON or ON/ON/ON), then DTC P1810 sets. If the PCM detects a gear range Other than the one indicated, then DTC P1810 sets. DTC P1810 is a Type B DTC.

Conditions for Running the DTC
^ The engine speed is greater than 500 RPM for 5 seconds and not in fuel shut Off.
^ The system voltage is 9-18 volts.

Conditions for Setting the DTC
DTC P1810 sets when at least one of the following cases occurs:

Case 1
The TFP manual valve position switch indicates an illegal switch combination for 60 seconds.

Case 2
^ No VSS DTCs P0502 or P0503 are set.
^ The vehicle speed is less than 16 km/h (10 mph).
^ TFP manual valve position switch indicates REVERSE, D2 or D4 for 7 seconds at engine start up without indicating PARK or NEUTRAL.

Case 3
^ No TP sensor DTCs P0121, P0122 or P0123 are set.
^ No VSS DTCs P0502 or P0503 are set.
^ No A/T ISS sensor DTCs P0716 or P0717 are set.
^ No 1-2, 3-4 SS valve DTCs P0751 or P0753 are set.
^ No 2-3 SS valve DTCs P0756 or P0758 are set.
^ The TP angle is greater than 9%.
^ The vehicle speed is more than 8 km/h (5 mph).
^ The engine torque is 70-230 N.m (50-170 lb ft) and one of the following conditions occurs:
- The gear ratio indicates REVERSE, D4, D3, D2 or D1 and the TFP manual valve position switch indicates PARK or NEUTRAL for 5 seconds.
- The gear ratio indicates D4, D3, D2 or D1 and the TFP manual valve position switch indicates REVERSE for 7 seconds.
- The gear ratio indicates REVERSE and the TFP manual valve position switch indicates D4, D3, D2 or D1 for 5 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the conditions for setting the DTC are met.
^ The PCM commands maximum line pressure.
^ The PCM freezes shift adapts.
^ The PCM assumes D4 for shifting.
^ The PCM stores DTC P1810 in PCM history.

Conditions for Clearing the MIL/DTC
^ The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
^ A scan tool clears the DTC from the PCM history.
^ The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
^ Inspect the wiring at the PCM, the transmission 20-way connector, the TFP manual valve position switch connector and all Other circuit connecting points for the following conditions:
- A backed out terminal
- A damaged terminal
- Reduced terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
^ If a transmission overhaul was performed, ensure that the transmission fluid is at the proper level. A low fluid condition may set this DTC.
^ Inspect the TFP manual valve position switch seals for damage.
^ Inspect the TFP manual valve position switch for debris, or loose rivets.






Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the indicated range signal to the manual valve range actually selected.
4. This step tests for correct voltage from the PCM to the transmission 20-way connector.
6. This step tests for a short together between circuits 1224 (PNK), 1225 (DK BLU) and 1226 (RED).