Transmission code P1811

GAMBITEER77

MEMBER
2000 SATURN SW2
3.0L
V6
2WD
AUTOMATIC
150,000 MILES

My car is giving a service wrench light and a reduced power light immediately upon start up. I cleared the code with my scan tool, and it drives like new. As soon as I shut it off and restart, it's back to square one. I've read about replacing the pressure solenoid in the transmission but am hesitant. Shouldn't the ECM take a little time diagnosing before immediately going into limp mode?

6 Replies

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

If there is a transmission code, usually it requires the vehicle to be placed in gear and moved. What is the code you are getting?

Let me know.

Joe

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Thursday, February 24th, 2022 AT 8:15 PM

GAMBITEER77

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5 POSTS

P1811. I've cleared and driven it multiple times. Shut the car off and immediately pops the code and reduced power.

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Thursday, February 24th, 2022 AT 8:26 PM

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

Please confirm the engine size for me. The only option I show is a 4 cylinder, 1.9L. See pic below. Also, the code, P1811, isn't identified for this vehicle. Could we have the wrong model year or model? See pic 2. It shows where the codes end for me to diagnose.

I know by heart that the code (P1811) is related to the transmission pressure control solenoid, but I can't find specifics for this vehicle.

Let me know and I'm sorry for the confusion.

Joe

See pics below.

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Thursday, February 24th, 2022 AT 8:51 PM

GAMBITEER77

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5 POSTS

2000 Saturn LW2 3.0 V-6.

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Friday, February 25th, 2022 AT 12:15 AM

GAMBITEER77

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A little history: I just replaced the throttle body because I was getting IAC and TPS error codes (built into TB can't replace separately) That fixed those issues. Now this P1811 has me perplexed.

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Friday, February 25th, 2022 AT 10:22 AM

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

That makes sense. Above it says SW2. Now I found the correct engine and the code is relevant. LOL

Okay, the code is related to the pressure control solenoid. You asked if it should be set immediately after clearing the code and the answer is no. For the code to set, the shift time has to be greater than 0.65 seconds at maximum pressure, for a total of two times during the same ignition cycle. Therefore, it has to be driven.

You clear it and it works perfectly until it is shut off. Then it starts over without driving. It leads me to think it is electrical (a short) which could be at the PC solenoid, PCM/TCM, or between the two.

If I had this, first I would inspect the connectors at the PCM/TCM. Make sure they are tight, clean, and not damaged.

Next, confirm the wiring between the module and transmission is not damaged as well as the connector at the transmission.

If that checks good, then I would drain the fluid and remove the PC solenoid valve and see if it is damaged in any way and if there is a wiring problem in the transmission.

Let me know if you have already done these things.

Take care,

Joe

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