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Volvo A35c high gear stuck in first throwing fault code 492

colts81990 ยท 2026-02-09 20:39

Have a Volvo A35c that will shift through all the gears in low speed but throws a code of 491. Put it in high speed and it's stuck in first and will not shift up throws a code of 492. Just curious if anyone has seen this before by chance.

Replies9
  1. #1sfrs42026-02-10 11:47

    Whats before the 491/492? is this code on contronic or some A/M reader?

  2. #2colts819902026-02-10 20:07

    The codes come on the contronic in the book the code says code 491 slipping turbine speed (input) higher than output speed. 492 code is slipping turbine speed (input) is lower than speed (output)

  3. #3colts819902026-02-10 20:08

    Some pictures of the codes in the book

  4. #4Simon C2026-02-11 23:42

    How many hours on the unit. Is there any other info on previous repairs , or is it just started to act up now. Have you opened the transmission filter and checked the pleats of paper for something coming apart. Does the oil smell burn't. Just asking. Simon C

  5. #5sfrs42026-02-12 09:56

    so as Simon C says, check your filter and oil strainer in the sump, if the oil smells burnt then it's more than probably slipping. this could be down to worn clutch plates or broken pressure plates etc.

  6. #6colts819902026-06-23 14:00

    Put new transmission in throw same codes still

  7. #7ianjoub2026-06-23 14:12

    sorry for the threadjack: I have an A30c. Do you shift these on the fly or do you select an appropriate gear while stationary and go?

  8. #8Simon C2026-06-23 22:16

    You probably need to check the harnesses that feed the transmission solenoids for weakness or opens. Did you open the filter as I posted in post#5 to see what was in. Was the Transmission done by a dealer or did you do yourself. Do you have electrical schematics for the unit, and how about a service manual. Were gauges hooked up to it and pressures checked. We are not there and just asking. Simon C

  9. #9sfrs42026-06-25 03:00

    did you have just the transmission changed? did you change out the torque convertor as well?