Transmission starts slipping after some driving - Throttle Position Sensor???
03-11-2014, 10:20 PM
#1
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Transmission starts slipping after some driving - Throttle Position Sensor???
Hi
I really like my 91 Honda Accord, even though it drives me crazy.
The transmission works fine when I start driving. It shifts hard sometimes but it does his job. After some time it seems that the shiftings get smoother until it would start slipping. Most of the time when shifting from gear 1 to 2. Then I drive on the side, turn the engine off and immediately on again and it works again for a short time.
When I bought the car 2 months ago, the Speed Sensor was broken which made the car not shift from gear 1 to 2 sometimes and the speedmeter fail sometimes. So I replaced it with a cheap one from ebay. It worked, even though the speed in the dashboard seems around 10mph to high. Also it would often shift at higher rpm. After driving 1000 miles the car started with slipping randomly.
What I did so far that didn't help:
- changed Vehicle Speed Sensor (as stated above)
- changed Solenoids
- changed transmission fluid
- changed NM main shaft speed sensor
- looked into the TCU and it looks fine, nothing fried
Some more weird things:
- the brake lamp warning light stays sometimes on after starting the car but all lights are actually working or it comes on during driving -> turn of/on the engine and light will go away
- sometimes when this warning light was on, the car would have trouble shifting into second gear (as it had before I changed the VSS)
- sometimes when the car stands still on a traffic light for example, something starts clicking and it sounds like it comes from behind the dashboard or near the engine
- when I release the brake this clicking stops
Does someone have an idea what could cause the slipping? Is it correlated to the brake light lamp?
I also removed the cable to the throttle position sensor today to see if this might be the cause. The car didn't shift nicely but it also didn't slip. Or could it be the torque converter?
Please help me out. As a student I can't really afford getting it fixed in a repair shop.
Thanks a ton!
I really like my 91 Honda Accord, even though it drives me crazy.
The transmission works fine when I start driving. It shifts hard sometimes but it does his job. After some time it seems that the shiftings get smoother until it would start slipping. Most of the time when shifting from gear 1 to 2. Then I drive on the side, turn the engine off and immediately on again and it works again for a short time.
When I bought the car 2 months ago, the Speed Sensor was broken which made the car not shift from gear 1 to 2 sometimes and the speedmeter fail sometimes. So I replaced it with a cheap one from ebay. It worked, even though the speed in the dashboard seems around 10mph to high. Also it would often shift at higher rpm. After driving 1000 miles the car started with slipping randomly.
What I did so far that didn't help:
- changed Vehicle Speed Sensor (as stated above)
- changed Solenoids
- changed transmission fluid
- changed NM main shaft speed sensor
- looked into the TCU and it looks fine, nothing fried
Some more weird things:
- the brake lamp warning light stays sometimes on after starting the car but all lights are actually working or it comes on during driving -> turn of/on the engine and light will go away
- sometimes when this warning light was on, the car would have trouble shifting into second gear (as it had before I changed the VSS)
- sometimes when the car stands still on a traffic light for example, something starts clicking and it sounds like it comes from behind the dashboard or near the engine
- when I release the brake this clicking stops
Does someone have an idea what could cause the slipping? Is it correlated to the brake light lamp?
I also removed the cable to the throttle position sensor today to see if this might be the cause. The car didn't shift nicely but it also didn't slip. Or could it be the torque converter?
Please help me out. As a student I can't really afford getting it fixed in a repair shop.
Thanks a ton!
03-11-2014, 11:29 PM
#2
MM Gruppe B
Re: Transmission starts slipping after some driving - Throttle Position Sensor???
If the brake lamp is coming on it could be that the brake fluid is low, or the hand brake switch is sticking.
With a voltmeter backprobe the TPS and look for any dead spots. It should be a linear voltage change when opening the throttle. A dead TPS will cause no upshifts. Same with the TW(ECU thermoresistor) if it is damaged it too will affect shifting.
Check your grounds, 90-93 cars have a bundle of ground wires at the bottom of the thermostat housing. If the groudns are loose or corroded this will affect the voltage the ECU sees which will affect drivetrain operation. Also check your battery for full charge, and battery leads are clean and tight.
With a voltmeter backprobe the TPS and look for any dead spots. It should be a linear voltage change when opening the throttle. A dead TPS will cause no upshifts. Same with the TW(ECU thermoresistor) if it is damaged it too will affect shifting.
Check your grounds, 90-93 cars have a bundle of ground wires at the bottom of the thermostat housing. If the groudns are loose or corroded this will affect the voltage the ECU sees which will affect drivetrain operation. Also check your battery for full charge, and battery leads are clean and tight.
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