Trans

[SUPERCHARGER_GTP]

What`s The Code P1811 D Whit Last D , The Scanner Send Me This Code Thanks

[BIG-L]

Here is a little info from GM

General Motors warns that a variety of 1999 and 2000 vehicle using the 4T65-E transmission with 3.4, 3.5, and 3.8-L engines can experience erratic shifting. The problem can be intermittent or consistent enough to set a P1811 or P0748 diagnostic trouble code (DTC). The symptoms can be harsh garage shifts or upshifts, soft shifts, shudders on hard acceleration, or erratic shifts. During diagnosis, line pressure can be too low or too high, compared to desired pressure.

Models affected are 1999-2000 Buick LeSabre, Park Avenue, Regal and Riviera, 1999 Chevrolet Lumina, Monte Carlo, and Venture, 1999 Oldsmobile Eighty-Eight, Intrigue and Silhouette, 1999 Pontiac Bonneville, Grand Prix and Montana with transaxles (Regular Production Option (RPO) MN3, MN7 and M15) and engines (RPO LA1, LX5, L36 and L67; VINs E, H, K and I).

The problem above may be due to one of three conditions:


Sediment inside the pressure control solenoid (PCS), causing a binding in the PCS valve.

Sediment in the valve body, causing the torque signal regulator valve to stick.

Incorrect transaxle oil level.
Any of these conditions affects line pressure in the transmission.

Diagnosis and correction

Any of the symptoms may be intermittent, so this test should be performed at least three times.

Follow the diagnostic procedure for checking line pressure. Use the line pressure specification table to determine if actual pressures are within the desired ranges specified, as shown in Table 1.

The scan tool can only control the PCS in Park and Neutral with the vehicle stopped. This protects the clutches from extremely high or low pressures in Drive or Reverse ranges.

The pressures in the table assume a temperature of 70?C (158?F). Pressures will vary with a change in temperature.

If the actual pressures are not within the values specified, clean the valve body and replace the PCS if necessary. Check the pressures with the new PCS to be sure the new PCS is responding correctly.

Refer to the automatic transaxle section of the service manual for the proper repair procedure.

Before performing a line pressure check, check that the pressure control solenoid (PCS) valve is receiving the correct electrical signal from the powertrain control module (PCM).


Attach a scan tool to the diagnostic connector.
Caution: Always keep the brakes applied to prevent unexpected vehicle motion. Personal injury may result if the vehicle moves unexpectedly.
Set the parking brake and start the engine.
Check for a stored DTC.
Repair the vehicle, if necessary.
Check the fluid level, using the transmission fluid checking procedure.
Check the manual linkage for proper adjustment.
Turn the engine Off. Remove the oil pressure test hole plug and install the J-21867 universal pressure gauge.
Put the gear selector in PARK range and set the parking brake.
Start the engine and allow the engine to warm up at idle.
Total test running time should not be longer than two minutes to prevent transmission damage.


Access the PCS valve control test on the scan tool.
Increase the current to the PCS from 0.0 to 1.0 amps in 0.1 amp increments. Allow the pressure to stabilize for five seconds after each pressure change. Read the corresponding line pressure on the gauge.
Refer to the line pressure specification table. If pressure readings differ greatly from the table refer to diagnosis of incorrect line pressure in the service manual.
Remove the pressure gauge, and turn the engine Off.
Apply GM #12345382 sealant to the oil pressure test hole plug. Install the plug and torque to 12 N?m (106 lb-in).


~Larry~

[Phoenix69]

Does the 1997 GP GT have serious transmission problems as well?

[atxchip]

What is that 'scan tool' you're referring to? I've been using AutoXray's for some time now, but, of course, it just reads codes and basic sensor values ...can't 'run' any tests, like varying the current through the PCS. Are there any scan tools that can go that far that are consumer accessible? I mean several hundred dollar range ...I did email AutoEnginuity folks but apparently there's no configuration of their setup that can do this. All for 2000 Montana of course ...mine has the hard shift symptoms when hot - can be eliminated often by just stopping engine and restarting!