Issue Summary:
- In the 2000 model year, some Mitsubishi F4A40/50-series transaxles were equipped with newly designed plastic-body solenoids.
- A Mitsubishi or Hyundai vehicle may arrive at your shop with code P1723 or Mitsubishi code 54, or in limp mode (3rd-gear starts) with no codes.
- Before or after overhaul, a Mitsubishi or Hyundai vehicle may exhibit a shudder or slip while being driven in reverse.
- Before or after overhaul, a Mitsubishi or Hyundai vehicle may go to neutral while taking off in 1st gear or while making a 2-1 downshift during a stop.
In the 2000 model year, some Mitsubishi F4A40/50 series transaxles were equipped with newly designed plastic-body solenoids.
The reason for the change was calibration issues. The flow rate of the plastic-body solenoid is 1.8 liters per minute. The previous-design metal-body solenoids, which are still in use on other models, flow at 2.5 liters per minute.
The solenoids are the only change and are model dependent. Refer to Figure 1 for identification of the new solenoid. The part number is etched into the end of the solenoid casing.
See Figure 2 for the solenoid locations on the valve body of the F4A series front-wheel-drive models.
The two different solenoids are not interchangeable because of the flow rate, although they will fit into all the valve-body bores. Refer to the chart in Figure 3 for model applications of both versions of the solenoid.
A Mitsubishi or Hyundai vehicle equipped with an F4A40/50-series transaxle may arrive at your shop with a Transmission Control Relay code P1723 or Mitsubishi code 54, or in limp mode, which is 3rd-gear starts, with no codes.
The cause may be that the transmission-control relay is damaged from water dripping down onto it from a leaking heater core just above the relay on the center firewall (see Figure 4). The transmission-control module, engine-control module and transmission-control relay are on the floor behind the center console. When condensation forms inside of it, the relay cannot close and connect the 12 volts needed to power up the solenoids in the transmission.
Mitsubishi models – Refer to Figure 5 and back-probe into terminals 9 and 10 of the case connector to see whether there is battery voltage when the ignition is switched on.
If there is no voltage, refer to partial wire schematic in Figure 6. Verify that terminal 2 of the transmission-control relay is a good ground. Verify that terminal 1 has battery voltage from fuse 13 with the ignition on. Verify that there is battery voltage from terminal 89 of the TCM when the ignition is switched on. If all these check correctly, turn the ignition on and probe into terminal 3 at the transmission-control relay. If there is no voltage coming from terminal 3, replace the transmission-control relay.
Note: This relay circuit is very similar to the circuit in the 604 family. If there is a problem in the relay circuit, voltage may be sent to pin 4 at the relay for less than two seconds and then turned off. This may not set a relay code and can be easy to miss, so be careful!
Replace the heater core and the transmission-control relay.
Before or after overhaul, Mitsubishi and/or Hyundai vehicles equipped with F4A40/50-series transaxles may exhibit a shudder or slip while being driven in reverse.
The cause may be that the overdrive-/reverse-clutch drum is cracked around the weld on the back of the drum (see Figure 7).
Caution: This crack is easy to miss!
Replace the overdrive-/reverse-clutch drum, and renew the piston seals (see Figure 8).
Before or after overhaul, Mitsubishi and/or Hyundai vehicles equipped with F4A40/50-series transaxles may exhibit a neutral at 6 mph while in 1st gear after taking off from a stop or while the vehicle is coming to a stop and making a 2-1 downshift. When the shifter is moved to manual low, 1st gear will re-engage.
The cause may be a bad low sprag. Figure 9 shows the computer strategy of the low-/reverse-clutch application through the low/reverse solenoid. The chart shows that the low/reverse clutch is turned off at 6 mph. It is the responsibility of the low sprag to hold from 6 mph until the 1-2 upshift occurs. The low sprag also has to come back on during the 2-1 downshift. If the sprag does not hold, the neutralizing effect will result. Notice that when the selector is in manual low, the low/reverse clutch stays on in 1st gear.
Replace the low sprag (see Figure 10) and ensure that the inner and outer races are good.
Refer to Figure 10 for correct assembly of the sprag in the output internal ring gear, and verify that the carrier freewheels in the correct direction (see Figure 11).
April 2008 Issue
Volume 25, No. 4
- Mitsubishi: New Plastic-Body Solenoid
- Mitsubishi/Hyundai: Transmission Relay Code P1723 or Mitsubishi Code 54
- Mitsubishi/Hyundai: Shudder or Slip in Reverse
- Mitsubishi/Hyundai: Neutralizing at 6 mph or During a 2-1 Downshift