Here we go again: '03 Explorer DTC's P0733/P0745

Wife called me at work with the news that OD/Off Light was flashing and the Explorer (190,000miles) is not shifting into 3rd gear (just got done Engine R&R for chains, guides, tensioners etc. I did all the work in my very limited spare time and it was running awesome).

Got home ran my scanner and pulled a FF DTC with P0745 and P0733. This does not look good. Before I pull the tranny for replacement of a broken band, are there ANY other items to check that could cause this problem?

UPDATE: Took it for a test drive. 1-2 shifts fine, 3rd gear flares, let off gas and it will eventually drop into 4th gear as long as speed doesn't drop too much during flare of third gear. 4-5 works. But third gearis non existent, just freewheels, rpms will simply increase and speed will drop. This is pretty much what happens on a hill unless you downshift and gas it up in mph then do the throttle trick to get the explorer to skip 3rd and drop into 4th. Then you can give it more gas and accelerate in 4th... otherwise the only option is to creep up the hill in 2nd gear, because youll never get speed in third and will never go to fourth once in 3rd.. Flat ground you can modulate the throttle to get out of the flaring third and then drop into 4th which will then stay in gear fine and eventually drop into 5th and TC will lock up as normal.

It looks grim at this point. We were without the explorer for a month and dropped about $1000 in parts for new chains, tensioners, gaskets, radiator, blend door motor, plugs, wires, t-stat housing, etc. etc. Just solved some electrical problems too... got 2 days of joy before todays surprise. Never had this issue before.

What should I check out short of dropping the entire tranny and replacing it with a good used unit? I am in no mood to rebuild the tranny. I have way too much going on before the snow flies. And I'm not financially in a position to pay a garage $2000-$3000 for a job like this on a vehicle that isn't even worth $5000.

Mike-in-Maine said:

Wife called me at work with the news that OD/Off Light was flashing and the Explorer (190,000miles) is not shifting into 3rd gear (just got done Engine R&R for chains, guides, tensioners etc. I did all the work in my very limited spare time and it was running awesome).

Got home ran my scanner and pulled a FF DTC with P0745 and P0733. This does not look good. Before I pull the tranny for replacement of a broken band, are there ANY other items to check that could cause this problem?

UPDATE: Took it for a test drive. 1-2 shifts fine, 3rd gear flares, let off gas and it will eventually drop into 4th gear as long as speed doesn't drop too much during flare of third gear. 4-5 works. But third gearis non existent, just freewheels, rpms will simply increase and speed will drop. This is pretty much what happens on a hill unless you downshift and gas it up in mph then do the throttle trick to get the explorer to skip 3rd and drop into 4th. Then you can give it more gas and accelerate in 4th... otherwise the only option is to creep up the hill in 2nd gear, because youll never get speed in third and will never go to fourth once in 3rd.. Flat ground you can modulate the throttle to get out of the flaring third and then drop into 4th which will then stay in gear fine and eventually drop into 5th and TC will lock up as normal.

It looks grim at this point. We were without the explorer for a month and dropped about $1000 in parts for new chains, tensioners, gaskets, radiator, blend door motor, plugs, wires, t-stat housing, etc. etc. Just solved some electrical problems too... got 2 days of joy before todays surprise. Never had this issue before.

What should I check out short of dropping the entire tranny and replacing it with a good used unit? I am in no mood to rebuild the tranny. I have way too much going on before the snow flies. And I'm not financially in a position to pay a garage $2000-$3000 for a job like this on a vehicle that isn't even worth $5000.

Click to expand...

Are you able to use an ohmmeter? What makes you believe a band may be at fault? P0745 is "Pressure Control Solenoid A, Shorted Circuit". P0733 is "Gear Ratio Error, Third Gear". There is every chance the solenoid has failed. It is the particular one which allows high fluid pressure to be present during 3rd. gear. No pressure, no 3rd. gear. The P0733 confirms that shaft speed ratios are not correct when 3rd. gear is being called for.

If the solenoid proves to be shot electrically, replacing it involves obtaining a replacement (new) solenoid module, as the solenoids (all 8 of them) are not individually replaceable. A reasonably skilled person can do this job, involving removal of the oil pan, old solenoid module, and installation of the new module. Probably the most difficult part is refilling the trans. with oil! If you get that far into it, a simple trick will be outlined. Are you game? imp

Too bad trans. trouble had to come on the heels of the previous.

JK080, what do you think? You know more about this stuff than me!

imp, your positive vibes are noted (with skepticism, but still noted)
This is a 2003 Explorer 5R55S (V code) tranny, also.

Mike-in-Maine said:

imp, your positive vibes are noted (with skepticism, but still noted)
This is a 2003 Explorer 5R55S (V code) tranny, also.

Click to expand...

That I know. The previous, I can't decipher. Do you want to try to verify the cause of the DTC or monkey around? imp

imp said:

That I know. The previous, I can't decipher. Do you want to try to verify the cause of the DTC or monkey around? imp

Click to expand...

Well, if I was monkeying around I wouldn't have given you all the info I gave. Seems much more than a lot of OP's provide. The part you cant decipher says Im skeptical that this would be such a simple fix (I do have the right to be skeptical, don't I?) but that I recognize your positive attitude. A Positive attitude is a good thing. I really do appreciate the help and the positive attitude!

Will be looking forward to any more posts here, because even if Im skeptical, I do not want to drop and tear down a tranny... and I cant do it at this point in time anyway, due to schedule and weather... so I'll eagerly await help here. My sincere thanks.

oh, and to answer your question I am VERY game.. not ready to give up. Step 1?

Mike-in-Maine said:

Well, if I was monkeying around I wouldn't have given you all the info I gave. Seems much more than a lot of OP's provide. The part you cant decipher says Im skeptical that this would be such a simple fix (I do have the right to be skeptical, don't I?) but that I recognize your positive attitude. A Positive attitude is a good thing. I really do appreciate the help and the positive attitude!

Will be looking forward to any more posts here, because even if Im skeptical, I do not want to drop and tear down a tranny... and I cant do it at this point in time anyway, due to schedule and weather... so I'll eagerly await help here. My sincere thanks.

oh, and to answer your question I am VERY game.. not ready to give up. Step 1?

Click to expand...

Now yer talkin'! Get under the vehicle with a D.C. Ohmmeter, disconnect the at-transmission electrical connector, and looking at the portion of the connector remaining on the transmission case, it's terminals are numbered 1 through 6, right hand side, top to bottom, 11 through 16 left hand side, top to bottom. Between terminals 3 and 11, the ohmmeter will read 3.3-7.5 ohms if the Pressure Control Solenoid A has no coil fault. At the same time, on a high scale, check between either 3 or 11 and a good, clean, ground, perhaps scratch a shiny spot on the vehicle frame. That check looks for a short circuit to ground, if OK, resistance will be very high. If both checks are OK, grab the harness and check resistance between connector terminal 11 and ground. Should be very high; if lower than 1000 ohms, disconnect the big connector from the PCM underhood, and do the same check again. This verifies a short to ground does not exist between the transmission connector and the PCM, somewhere in the harness. Such harness short-circuits happen where the harness may inadvertently have lain on a very hot surface, or had insulation scraped through by some sharp protruding edge.

If no short to ground is evident in the harness, but either check of the solenoid coil fails to meet resistance specs, it's a pretty good bet that solenoid is faulty. Help any? imp

imp said:

...disconnect the at-transmission electrical connector, and looking at the portion of the connector remaining on the transmission case...

Click to expand...

You do realize the transmission, exhaust, suspension, harnesses, hoses, brackets etc are all in place right?

(SARCASM WARNING) I tried to make myself 6" tall and use a string to climb up on top of the connector socket but I couldn't. My hands are not those of a 5 year old or petite woman, my head is full size. Even if I had a mirror of some sort, within this tiny upside down 3"x3x3" airspace I would not be able to manipulate a mirror, aim a flashlight and utilize two ohmmeter lead probes all at the same time even if I did have 5 monkey hands, a tiny head and a 2 foot long owl neck.

Please excuse my sarcasm, but spending an hour trying to make myself fit into a shoebox sized nook really agigated me. What am I missing here? It was tricky enough getting the bolt off the tranny wiring harness socket, but not impossible. Looking down into that hole however is not possible as far as I can see with the tranny and exhaust and wheels and cross members and brackets and linkages hooked up.

What I did do, however, is work from the under hood PCM junction 175B and trouble shoot via fuse JBox terminal F-37 (fuse removed).

All of the following resistance checks were within range:
Shift Solenoid "A" 175B[1]-to-F37 = 27.5
Shift Solenoid "B" 175B[2]-to-F37 = 27.4
Shift Solenoid "C" 175B[3]-to-F37 = 27.5
Shift Solenoid "D" 175B[4]-to-F37 = 27.6
PC Solenoid "A" 175B[7]-to-F37 = 6.0
PC Solenoid "B" 175B[13]-to-F37 = 6.0
PC Solenoid "C" 175B[12]-to-F37 = 6.2
TCC Solenoid 175B[5]-to-F37 = 12.1
TFT Sensor 175B[17]-to-F37 = 11.9
Turbine Speed Sensor 175B[17/27] = 432
Intermediate Speed Sensor 175B[17/21] = 431
Output Speed Sensor 175B[17/26] = 427


Additionally, I did do the ground / short test on terminal at the PCM harness.

Can I do the tests all from the PCM under hood socket? I would think so long as the harness is not compromised, the tests should be doable. The tests I did do were resistance checks from the harness pin outs to JBox F37 terminal. But the spec ranges seem to be the same.
Am I missing anything?

Mike, it's hard for me to believe you're playing a game with me. If you had all those specs available before, the various pin-outs, etc., why the hell have I spent a couple of hours fruitlessly?

I actually thought it might be difficult to access under the vehicle. Sorry on that. Yeah, no reason why you cannot do the checks up at the top end.

You seem able, capable, and knowledgeable enough to do all these things by yourself; thus, why ask for help?

You must also be aware, then, that a solenoid, being an electromechanical device, can be inoperative due to mechanical failure, right? The Dealers use a sophisticated machine which simulates all the transmission functions, checking them against standards, and usually come up with the correct diagnoses. We "garage & basement" guys enjoy no such privilege.

In my own case, I spotted a "no lock-up" of the TCC via my tach. At that time, I was green to the DTC system, had code read, the guy said TCC solenoid failure. Cost $75, we were 2000 miles from home, he suggested probable transmission damage if continued to drive. I drove all the way home with no TCC engaged, ordered a solenoid module, put it in, and the trans. has been fine since (3 yrs. now). That was when I started studying this **** in earnest.

Now, what else can I tell you? imp

Thanks imp. I didn't have the pinouts before, I found them today around the same time you made your post with pinoouts and directions. I used your post and the tech info I found, but both pieces of info were very useful... I just couldn't see how anyone could visually or physically access that trany connector... crazy stuff...

my question remains can I do the point to point resistance checks at the PCM connector, and if yes, what is the difference between using the JBox fuse point vs the points you've given using just the PCM points... honest question.

I will finish testing tomorrow after work to verify all the point-to-point checks you've given , but doing so at the PCM connection...

imp said:

Are you able to use an ohmmeter? What makes you believe a band may be at fault? P0745 is "Pressure Control Solenoid A, Shorted Circuit". P0733 is "Gear Ratio Error, Third Gear". There is every chance the solenoid has failed. It is the particular one which allows high fluid pressure to be present during 3rd. gear. No pressure, no 3rd. gear. The P0733 confirms that shaft speed ratios are not correct when 3rd. gear is being called for.

If the solenoid proves to be shot electrically, replacing it involves obtaining a replacement (new) solenoid module, as the solenoids (all 8 of them) are not individually replaceable. A reasonably skilled person can do this job, involving removal of the oil pan, old solenoid module, and installation of the new module. Probably the most difficult part is refilling the trans. with oil! If you get that far into it, a simple trick will be outlined. Are you game? imp

Too bad trans. trouble had to come on the heels of the previous.

JK080, what do you think? You know more about this stuff than me!

Click to expand...

I personally think that the intermediate band has broken or the intermediate servo has failed.

The fact that it tries to shift to 3rd tells me the computer sent the signal, the solenoid worked, the shift valve moved, the overdrive band released, the intermediate band should come on but can't. So basicly it shifted back into 1st with no engine braking.

You could check the intermediate band adjustment, if it screws in more than 3 turns the band is probably broke. Hopfully it will tighten, and you can just adjust it back out 2 turns and pull the servo, hopfully thats where the failure is.

My bet is on the band.

JK080 said:

I personally think that the intermediate band has broken or the intermediate servo has failed.

The fact that it tries to shift to 3rd tells me the computer sent the signal, the solenoid worked, the shift valve moved, the overdrive band released, the intermediate band should come on but can't. So basicly it shifted back into 1st with no engine braking.

You could check the intermediate band adjustment, if it screws in more than 3 turns the band is probably broke. Hopfully it will tighten, and you can just adjust it back out 2 turns and pull the servo, hopfully thats where the failure is.

My bet is on the band.

Click to expand...

Thank you for this! My question now is, why didn't PCM note discrepancy between expected shaft speeds, and throw a DTC about it? imp

imp said:

Thank you for this! My question now is, why didn't PCM note discrepancy between expected shaft speeds, and throw a DTC about it? imp

Click to expand...

He stated that his codes where p0745 and p0733.

P0733 is gear 3 incorrect ratio.

So my question is, if the intermediate servo failed how could that throw both codes and give same symptoms as broken band? I am also leaning toward a broken band as the culprit, but that's just because i'm a pessimist.

Mike-in-Maine said:

Thanks imp. I didn't have the pinouts before, I found them today around the same time you made your post with pinoouts and directions. I used your post and the tech info I found, but both pieces of info were very useful... I just couldn't see how anyone could visually or physically access that trany connector... crazy stuff...

my question remains can I do the point to point resistance checks at the PCM connector, and if yes, what is the difference between using the JBox fuse point vs the points you've given using just the PCM points... honest question.

I will finish testing tomorrow after work to verify all the point-to-point checks you've given , but doing so at the PCM connection...

Click to expand...

Using an ohmmeter, you have to be careful always that no voltage is present in the circuit being checked. Fuse F37 is dead as long as the PCM Power Relay is off, so your OK using either end of that fuse as your measuring point for the common connection of all the solenoids. What this means is that +12 volts is available on that common connection whenever Power Relay is "on", and whenever the engine is up and running. Each solenoid is turned "on" by the PCM by it's grounding the other sides of the solenoid coils, independently of each other. I hope I'm not explaining something here that's already cold turkey for you. The difference you ask about is this: you're including the resistance of the wire running from the PCM to the transmission as part of the measurement of the coil resistance. The resistance of that wire should be very low, say less than 0.1 ohm, so it doesn't upset the result at all, since coil resistance is many times that.

JK feels the issue is mechanical, as you can see. Self-diagnosis like these things have is not infallible, and the circuitry in the PCM can't be designed such that every possible foible be included in what it can detect.

Checking the screw-in of the band adjustment is a quick and easy suggestion, to find a broken band, or a major servo problem where the piston is no longer positioned real close to tightening on the band. I wouldn't think of it; he does this stuff for a living. What does he say, 2 turns? That is the "back-off" amount, then, when adjusting the band initially, which provides clearance so the drum can spin freely when the band is not applied. As the bands wear, the "screw-in" amount has to increase a little bit, maybe a turn, but if you try it, and the screw goes in much more than 2 turns, maybe all the way to the hilt, you have some busted parts. I'm betting on the other, solenoid problem. Why? In your position, you can invest $200 or $300 for a new sol. mod., put it in, yourself, and if the bet was wrong, pulling the transmission out and apart is a helluva lot bigger proposition, AND, at that point, if the issue were not solved by sol. replacement, you would likely want a NEW sol. module in the trans, after fixing the busted parts, anyway, wouldn't you?

Personally, I wouldn't put my trans. back in the vehicle after a major tear-down, with the old solenoids intact, unless they were pretty new. FWIW, in my case, the TCC sol. plunger bushing, made of bronze, had crumbled and broken out of place. The pieces were piled up on top of the valve body. The sol. could not move, PCM sensed circuit failure, however it does that, probably by looking at HOW LONG the higher-than-static coil current flowed (current is high if the plunger cannot attain center in it's tube). What a game....... imp

JK080 said:

He stated that his codes where p0745 and p0733.

P0733 is gear 3 incorrect ratio.

Click to expand...

Aw, ****! I forgot about that! Guess I'll never make it as a transmission man, with these new-fangled things! Give me an FX, FMX, C-6, I'm OK.

Thanks for your help! imp

imp said:

Aw, ****! I forgot about that! Guess I'll never make it as a transmission man, with these new-fangled things! Give me an FX, FMX, C-6, I'm OK.

Thanks for your help! imp

Click to expand...

I hear ya, rebuilt my first C4 in 1988 I believe... fun and easy. did a number of shift kits in valve bodies for friends too... then I grew up!

So, with 733 code are you still betting on solenoid?

Mike-in-Maine said:

So my question is, if the intermediate servo failed how could that throw both codes and give same symptoms as broken band? I am also leaning toward a broken band as the culprit, but that's just because i'm a pessimist.

Click to expand...

The servo piston itself can fail, sometimes they break, sometimes the molded lip seal will fail. This piston applies the band, if it has a problem the band cant apply, this means no 3rd.

The codes its setting is for gear ratio in 3rd p0733, the other code p0745 can be a companion code, it sets because of the p0733.

Most of these I see its the overdrive piston that fails more often, they break, the intermediate servo rarely fail, but it does happen.

Its common for the bands to break and they are the same band for both overdrive and intermediate locations.

We have one in the shop this week just for this, broken band.

imp said:

Aw, ****! I forgot about that! Guess I'll never make it as a transmission man, with these new-fangled things! Give me an FX, FMX, C-6, I'm OK.

Thanks for your help! imp

Click to expand...

I just finished a Dynaflow out of a 54 Buick Special this week, that thing was fun to go through. Cast iron and a one speed, with a low if needed.

JK080 said:

I just finished a Dynaflow out of a 54 Buick Special this week, that thing was fun to go through. Cast iron and a one speed, with a low if needed.

Click to expand...

Ha! Back then we called them "Dynaflop"! One or two years, maybe 55-56, Buick touted a "Variable Pitch Dynaflow" which might actually be the same as what you mentioned, it didn't shift at all, was a really dead slush box. imp

Well, I tried a few things today after work...

First I attempted to loosen the intermediate band nut to no avail. it is rusted on, it seems. the exposed threads have rust, the nut has rust, the tranny body obviously is aluminum and doesn't. I chose to abandon this idea as I predicted that if I did loosen the bolt, the adjuster stud would have been rusted in place onto the nut rendering the pair one. At that point I wouldn't be able to adjust or test or much else, let alone break the stud free from the nut. I didn't want to end the day on a bad note so I stopped before I created a real problem... I did however, squirt a good amount of AeroKroil on the bolt & stud. Well see what tomorrow brings...

Next, I decided to retest the electrical point resistances at the PCM connector for the solenoids, etc. I was getting readings that made no sense, had to switch between ranges constantly, (200/2k) to get readings. some pins would read on the 200 ohm range, others would not and would only read on the 2k ohm range but with the decimal moved 3 places. Some pins read "correct" in the correct ohm range and the correct range setting on the meter... others did not and the meter had to be switched... but switched readings were inconsistent with other switched readings.. it just wasn't making sense at all... either ranges were way off or there was something else going on... I didn't have this problem doing t he readings between the pins and the JBox fuse, but these were pin-to-pin readings. I suppose the harness could really be introducing some serious variability in the resistance readings.... after an hour of dinking around like this it was starting to get dark so I hooked it all back up and called it a night... oh well.

Explorer still runs the same.