Engine computer replacement
Can I replace only the engine computer box if it packed up ,or do I need to replace more components? White a key replacement what else needs to be replaced ?

Volvo offered two versions of the S40 sedan in 2004. The first generation returns with two trim levels: the base 1.9T and the new LSE. A second-generation S40 debuted midway through the year, as a 2004.5 model. This fully redesigned S40 included two new trim levels, called the 2.4i and the T5. The 2004.5 models are differentiated from their predecessor by a longer wheelbase, shorter overall length, and several mechanical changes.
There are now several engine and drivetrain options for the S40 lineup. First-generation models retain the turbocharged 1.9-liter inline 4-cylinder, which supplies 170 hp and 177 lb-ft of torque. The 5-speed automatic is again the only transmission offered. The new S40s have two engine options. The 2.4i is powered by a 2.4-liter inline 5-cylinder, providing 168 hp and 170 lb-ft of torque. The T5 houses a turbocharged version of the 2.4, which bumps horsepower to 218 and torque to 236 pound-feet. The 2.4i's powerplant can be mated to either a 5-speed manual or a 5-speed automatic transmission. The T5 has the 5-speed automatic option, but also upgrades to a 6-speed manual.
The LSE trim was available in very limited production, with just 2,500 units. This trim gets a special exterior finish and unique alloy wheels. The 1.9T returns without any significant changes for this final year of production. The new 2.4i comes with a familiar selection of features, like full power accessories, cruise control, keyless entry, a CD player, and heated power mirrors. This new model adds traction control. The T5 adds a trip computer and some additional leather interior trim.
Volvo has attempted to grab younger buyers with the S40, following the lead of entry-level luxury models like the Acura TL, Infinity I30, Audi A4, and Lexus ES. The S40 has an attractive base price, but the sub-$25,000 entry point becomes a distant memory if additional amenities are desired. The S40's interior presentation is reminiscent of the larger and more expensive Volvos, but closer inspection will reveal the presence of many lower-quality materials.
Can I replace only the engine computer box if it packed up ,or do I need to replace more components? White a key replacement what else needs to be replaced ?
I have a 2004 Volvo S40 automatic transmission. Two days ago I accidentally spilled water onto the shifter, but I have done this a number of times over the years with no consequences. The next day I went to take it from park to drive, and it got stuck in neutral. I had to get it towed. The tow truck driver stuck a screw driver in the small square box to the bottom left of the shifter. Within seconds he got the car into drive. I drove it home and parked it. He theorized the water was the problem and it would take a few days to dry out. Today I wanted to see if it had recovered. I attempted to take it from park to drive, but it got stuck in neutral. After messing around with a screw driver, I was able to get it from neutral to drive but never back past neutral into park. At present the car still has the keys in the ignition and is sort of off but still in neutral. Also the computer says "GEAR SERVICE REQUIRED".
car seemed to hesitate at first. thought it was transmission,.also rpm guage and temperature gauge were not working. Then check engine light went on also red hazard light in middle of gauges. what could it be?
A warning light with a picture of a car with a x came on for a min Would this have anything to do with the transmission going out the next day?
Air Conditioning
Automatic climate control front air conditioning
Airbags
Dual front airbags · Front side airbags · Front side curtain airbags
Audio System
Single disc in-Dash CD · MP3 player: CD MP3 Playback · AM/FM radio
Brakes
ABS: 4-wheel
Comfort Features
Steering wheel trim: leather
Convenience Features
Multi-function remote: keyless entry · Steering wheel: tilt and telescopic · Steering wheel mounted controls: audio
Lights
Exterior entry lights: security approach lamps · Headlights: Xenon
Mirrors
Exterior mirrors: power · Inside rearview mirror: electrochromic
Rear Seats
Type: split-bench
Roof
Moonroof: power
Seats
Front seat type: bucket · Heated: front seats · Upholstery: leather
Tires
Type: all season
Tires and Rims
Wheel type: aluminum alloy
Windows
Front wipers: intermittent
Air Conditioning
Automatic climate control front air conditioning
Airbags
Dual front airbags · Front side airbags · Rear side curtain airbags
Audio System
Antenna Type: power · Single disc in-Dash CD · AM/FM radio
Brakes
ABS: 4-wheel
Comfort Features
Shift knob trim: leather · Steering wheel trim: leather
Convenience Features
Multi-function remote: trunk release · Steering wheel: tilt and telescopic
Lights
Exterior entry lights: security approach lamps
Mirrors
Exterior mirrors: heated
Rear Seats
Type: split-bench
Roof
Moonroof: power
Seats
Front seat type: bucket · Heated: front seats · Upholstery: leather
Tires
Type: all season
Tires and Rims
Wheel type: aluminum alloy
Windows
Front wipers: intermittent
Airbags
Dual front airbags · Front side airbags · Front side curtain airbags
Audio System
Single disc in-Dash CD · MP3 player: CD MP3 Playback · AM/FM radio
Brakes
ABS: 4-wheel
Comfort Features
Shift knob trim: leather · Steering wheel trim: leather
Convenience Features
Memorized settings: driver seat · Multi-function remote: trunk release · Steering wheel: tilt and telescopic · Steering wheel mounted controls: audio
Lights
Exterior entry lights: security approach lamps · Headlights: Xenon
Mirrors
Exterior mirrors: power · Inside rearview mirror: electrochromic
Rear Seats
Type: split-bench
Roof
Moonroof: power
Seats
Front seat type: bucket · Heated: front seats · Upholstery: cloth
Tires
Type: all season
Tires and Rims
Wheel type: aluminum alloy
Windows
Front wipers: rain sensing
Air Conditioning
Automatic climate control front air conditioning
Airbags
Dual front airbags · Front side airbags · Rear side curtain airbags
Audio System
Antenna Type: power · Single disc in-Dash CD · AM/FM radio
Brakes
ABS: 4-wheel
Comfort Features
Shift knob trim: leather · Steering wheel trim: leather
Convenience Features
Multi-function remote: trunk release · Steering wheel: tilt and telescopic
Lights
Exterior entry lights: security approach lamps
Mirrors
Exterior mirrors: power
Rear Seats
Type: split-bench
Roof
Moonroof: power
Seats
Front seat type: bucket · Heated: front seats · Upholstery: leather
Tires
Type: all season
Tires and Rims
Wheel type: aluminum alloy
Windows
Front wipers: intermittent