Issue Summary:
- No reverse, no 1st and no 4th before and/or after overhaul of a Volvo 50-40LE/50-42LE may result from the solenoid screens being installed upside down during cleaning and servicing of the valve body.
- The transmission control module in some Kia vehicles may produce codes for a gear-ratio error, transmission-range-signal malfunction and/or converter-clutch malfunction even though it has not observed incorrect data or any malfunction.
- Honda recently released a product update for a problem with the intake air breather pipe and a no-reverse condition on the 2003 Accord.
The Technical Supplement in the August 2001 issue of Transmission Digest spoke about vehicles equipped with the 50-40LE or the 50-42LE transaxle, which may exhibit a condition of no reverse, no 1st and no 4th before and/or after overhaul. The cause is primarily that during cleaning and servicing of the valve body, the screens for the solenoids were installed upside down. This blocks feed oil to the solenoids and to the shift valves, as shown in Figures 1A and 2B.
Of course, mechanically failed shift solenoids also can produce the same complaint. The torque-converter-clutch (TCC) solenoid shown in Figure 2 has its own screen as well, and if this screen is installed upside down, it will prevent the converter clutch from applying. Code P0740 (TCC not engaging) or P0741 (TCC stuck off) also may be produced.
Figure 3 illustrates the correct placement for each of the solenoid screens, and figures 4 and 5 show how to check each of the shift solenoids and the TCC solenoid. In the event that replacement of the solenoids becomes necessary, we have provided both Volvo and Aisin-Warner part numbers.
- Solenoids 1 & 2 (Volvo Part Number) 6843783
- Aisin-Warner Number. . . . . 50 40 313 022 N-A
- TCC solenoid (Volvo Part Number) . . 6843784
- Aisin-Warner Number . . . . . 50 40 313 001 L-D
Kia vehicles such as the Sephia, Rio or Spectra may produce gear-ratio-error codes (P0731/32/33 and/or 34), transmission-range-signal malfunction (P0705) and/or converter-clutch malfunction code (P0740) even though the computer has not observed incorrect data or any malfunction.
Before 10/18/00, certain driving conditions would prompt the computer to produce these codes. The TCM in vehicles built after 10/18/00 uses a revised diagnostic routine that helped prevent the erroneous setting of these codes.
The TCM did not receive a part-number change when this new TCM logic was implemented. Check the production date of the vehicle. If it is Oct. 18, 2000, or later, the updated TCM should be in the vehicle. It is possible that the TCM previously has been replaced with an earlier version. If there is any doubt, locate the TCM – under the dash and to the left of the steering column – and remove it. On the TCM is a white label with the word Bosch written in the upper left corner (see Figure 6). To the right it says “Made in Korea.” Underneath those words is a six-digit number that provides the build date. The digits represent the year, month and date, in that order. The example in Figure 9 is May 30, 2001. Oct. 18, 2000, would appear as 001018. Any TCM built before this date will need to be updated.
The inhibitor switch also may require replacement. It was updated Nov. 22, 2001, and will have a stamping on the side of the switch with the same dating sequence as on the TCM; for example, 011122 would be Nov. 22, 2001. If the inhibitor switch has an earlier date, replacement with a new switch is recommended. Figure 7 provides a continuity-check chart for the inhibitor switch and an electrical-wiring diagram in the event further testing is required.
- Sephia TCM . . . . . . . . . . . . . . . .0K2AB 18 9E0B
- Spectra TCM . . . . . . . . . . . . . . . .0K2AB 18 9E0B
- Rio TCM . . . . . . . . . . . . . . . . . . . .0K32B 18 9E0
Honda recently released a product update for a problem with the intake air breather pipe and a no-reverse condition.
The first problem is caused by a weak hose clamp that allows excessive air to be sucked into the system, which also may cause the malfunction indicator lamp to illuminate.
The no-reverse condition can occur if the vehicle is stuck in the snow and the driver spins the wheels forward and backward at speeds greater than 12 mph. Under these conditions, the computer activates a reverse-inhibit feature. The problem is that the computer remains in the reverse-inhibit mode.
The vehicle will need to be returned to the dealer for the appropriate updates to correct both of these conditions. This also means that if one of these vehicle that has not received the updates comes into your shop for repairs, while testing the vehicle on the lift you may activate the reverse-inhibit feature and find yourself with a no-reverse condition.
To verify your no-reverse condition, locate the red wire going to shift solenoid “E” by referring to figures 8 and 9. If no voltage is on the wire while the shift selector is in reverse, the computer is in the reverse-inhibit mode.
September 2003 Issue
Volume 20, No. 9
- Volvo 50-40LE/50-42LE: Code P0740 or P0741
- Kia: Erroneous DTCs
- 2003 Honda Accord: No Reverse