Transmission banging

Tiny
SUEANNE
  • MEMBER
  • 1994 SATURN SL2
  • 75,000 MILES
1994 SL2, automatic transmission with 75,000 miles; purchased with transmission banging issue. We have replaced the valve body with a remanufactured valve body, it has sonnax pressure valve update. We replaced the input shaft nut, which wasn’t loose and tighten the output shaft. We added Lucas Transmission Treatment and new filter and fluid. We replace the engine control temperature switch, which made the coolant fan actually work. We replaced the serpentine belt, the wires and plugs. We cleaned the grounds on the engine & fender well and found a vacuum line off. We are still having the same issue with the transmission banging between all gears. The engine runs smoothly & idles great and all other aspects seem fine. After driving a while, the “service engine soon” light comes on and the transmission works perfect. As long as the light is on, the transmission is fine but once we shut the car off & restart it the light goes off, the transmission bangs again. When you jump across the diagnostic terminals it does not throw any codes.
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Sunday, November 27th, 2011 AT 10:20 PM

7 Replies

Tiny
RASMATAZ
  • MEMBER
Scan the transmission control module/PCM for code/s and find out what's popping up the CEL
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Sunday, November 27th, 2011 AT 10:29 PM
Tiny
SATURNTECH9
  • EXPERT
Just to add to this one does it at least flash out a code 12?What terminals are you jumping?The key is in the run position when you do this?Where did you buy the valve body?Also what sonnax upgrades did they do to valve body?There is the pressure regulator itself the spring the sleeve and the boost valve. How hard does it shift?I have a 1999 saturn SL2 and I did the all those sonnax upgrades myself and also did my brothers 1995 saturn SL2 my sister 1993 saturn SL1 and my friends 1995 saturn SL1. Those cars shifts pretty hard with the upgrades only when your really getting on it. Did you do a high and low pressure test before you changed the valve body?Did you also do a high and low pressure test after the valve body replacement?
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Monday, November 28th, 2011 AT 4:12 AM
Tiny
SUEANNE
  • MEMBER
We got some codes and checked online for what they mean but we are not 100% sure. The codes we got are as follows: 12 and 11 then the switch to the temp. Light we got 13 and 69. Can you verify these codes?
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Tuesday, November 29th, 2011 AT 12:15 AM
Tiny
SATURNTECH9
  • EXPERT
Code 12 means the computer is working. Code 11 is transmission codes present. Iam checking on the other two codes. So did they rebuild your old valve body or sell you a new valve body?Also did these codes come after replacing the valve body?
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Tuesday, November 29th, 2011 AT 12:24 AM
Tiny
SATURNTECH9
  • EXPERT
Code 13 is high line pressure in the transmission code 69 is line pressure actuator circuit shorted to voltage. My guess is you probably have a bad line pressure actuator in the valve body. Do you have a multimeter to do some testing?
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Tuesday, November 29th, 2011 AT 12:43 AM
Tiny
SUEANNE
  • MEMBER
They sent us a rebuilt valve body. We were so sure that was the problem, we just bought one but we have the original one! After we took the old valve body off, we checked all the actuators and all were on spec w/the ohms resistance. We have a multimeter. Do you think there could be a short in the wiring harness going to the valve body? To your knowledge, it looks as tho the wires going to the valve body originate at the PCM, we were going to check the wiring harness for a short. What do you think? Do you think both actuators would be bad?
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Tuesday, November 29th, 2011 AT 1:30 AM
Tiny
SATURNTECH9
  • EXPERT
Yes the wires to the transmission go back into the car to the computer.I think its the line pressure actuator that is bad though. Usually when you get a rebuilt valve body it has used actuators in it. So was it shifting hard with the old valve body?Or were the gears slipping delay in reverse etc?
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Tuesday, November 29th, 2011 AT 2:58 AM

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