tcu code 10?????

[H22A91CB7]

this is for the coolant switch being open or shorted, but my fan is coming on and my needle on my cluster is working, so why is the car trippin this code, ive tried resetting the ecu and all still no luck, coolant switch b has voltage when the car is off any suggestions?

[James Matteu]

Misguided Assumption

Your fan can come on even if there is a problem with one of the temperature switches, see my response to your weird electrical problem thread. Your TCU can see a problem with one switch and still run the system off the other, see below. Have you tested the switches yet?

...There are two switches, one is the primary switch, the other is a back-up that switches on at a higher temperature should something go wrong and the first does not switch the cooling fan on...

BTW, the needle on your dash has little to do with the operation of your Cooling Fans. The needle is driven by a thermistor, not a switch.

[H22A91CB7]

my bad, switch b has continuity with the car cold and off, read the haynes manual and it says no switch should have continuity while the car is warming up, and switch b does have continuity so its trippin my S light making it throw a code 10
switch A is working just fine, sending unit is fine

[H22A91CB7]

bump

[James Matteu]

bump

Um, dude, you need to replace Switch B with a known working Switch and retest. There is nothing more to do until you do that.

[H22A91CB7]

Um, dude, you need to replace Switch B with a known working Switch and retest. There is nothing more to do until you do that.

[H22A91CB7]

Um, dude, you need to replace Switch B with a known working Switch and retest. There is nothing more to do until you do that.

but wudnt it be a electrical issue in the wiring cas the switch only makes the contacts right?

[James Matteu]

Bad Switch

but wudnt it be a electrical issue in the wiring cas the switch only makes the contacts right?

The only external force that is supposed to influence Switch B is the temperature of the coolant. An electrical problem cannot make a temperature switch close. You have a bad switch. Switch B is only supposed to make a connection when your engine coolant is above 226 °F, c.f. the wiring diagram. As you stated, the switch is making a connection with the car cold and off; this malfunction is likely the cause of all your Cooling System issues. You will have to replace Switch B and retest the system to see if you find any other faulty components.

According to page 9-29 of the Helms Service Manual, Transmission Control Unit (TCU) Code 10's Possible Causes include:
- Disconnected water temperature sensor coupler
-Short or open in the water temperature sensor wire
-Faulty water temperature sensor
The last being applicable to your situation.

Change the switch, then retest.

[H22A91CB7]

The only external force that is supposed to influence Switch B is the temperature of the coolant. An electrical problem cannot make a temperature switch close. You have a bad switch. Switch B is only supposed to make a connection when your engine coolant is above 226 °F, c.f. the wiring diagram. As you stated, the switch is making a connection with the car cold and off; this malfunction is likely the cause of all your Cooling System issues. You will have to replace Switch B and retest the system to see if you find any other faulty components.

According to page 9-29 of the Helms Service Manual, Transmission Control Unit (TCU) Code 10's Possible Causes include:
- Disconnected water temperature sensor coupler
-Short or open in the water temperature sensor wire
-Faulty water temperature sensor
The last being applicable to your situation.

Change the switch, then retest.

ok

[H22A91CB7]

Ok man when you said replace Sensor B, are you talkin about the green connector?
[IMG][/IMG]


Or the thing screwed into the water neck?
[IMG][/IMG]


sorry about the dark pictures

[James Matteu]

"Green connector" is Coolant Temperature Switch A. "Water neck" is Coolant Temperature Switch B.

I work 12hr shifts as an Industrial Chemist. If I don't reply to a simple question right away, just be patient, I am not ignoring you, I just haven't seen the question yet.

[H22A91CB7]

"Green connector" is Coolant Temperature Switch A. "Water neck" is Coolant Temperature Switch B.

I work 12hr shifts as an Industrial Chemist. If I don't reply to a simple question right away, just be patient, I am not ignoring you, I just haven't seen the question yet.

gotcha man thanks

[H22A91CB7]

Replaced Switch B and and still getting a code 10, according to this:

chapter 9 of the service manual, here's a condensed version of its table:

1: Lock-up solenoid A
2: Lock-up solenoid B
3: Throttle angle sensor
4: Vehicle speed sensor
5: Shorted shift lever switch
6: Open shift lever switch
7: Shft solenoid A
8: Shift solenoid B
9: NC speed sensor (pre torque converter)
10: WT sensor (thermostat temperature)
11: Ignition coil (apparently the AT wants to monitor the ignition coil)
12-13: Undefined as of 1990
14: ECU (good luck)
15: NM speed sensor (intermediate shaft)

A more advanced look at the tcu codes, it is the WT sensor or whateva, I guess its speaking of the sensor on the thermostat housing

[James Matteu]

Good Job

Change the switch, then retest.

Okay, you changed Switch B, pulled the memory Fuse for the TCM or disconnected the battery for 5 min. Now you have to start over and conduct all the tests I laid out in the other thread you started for a cooling problem.

[H22A91CB7]

Okay, you changed Switch B, pulled the memory Fuse for the TCM or disconnected the battery for 5 min. Now you have to start over and conduct all the tests I laid out in the other thread you started for a cooling problem.

i disconnected the negative post on the battery and pulled the hazard and back up radio fuse for 5 mins