47RH OD/TPS Issue... HELP!!
#11
08-19-2009, 01:19 PM
Forgive me, but I'm at work and don't have the truck to look at....
Does the pcm ground by wire(s) or through its casing? The ring terminal you're talking about... is this where the bolt holding the harness screws in, or is it a "ring" end in the ground wire(s) where it connects to the body?
Trying my best to get figured out what I'm going to try first for when I get home, the clocks a tickin' on gettin this truck done! Thanks for all your help!!
Does the pcm ground by wire(s) or through its casing? The ring terminal you're talking about... is this where the bolt holding the harness screws in, or is it a "ring" end in the ground wire(s) where it connects to the body?
Trying my best to get figured out what I'm going to try first for when I get home, the clocks a tickin' on gettin this truck done! Thanks for all your help!!
#13
08-19-2009, 03:56 PM
I see do not see the ring termal... the only thing on the right side of the pcm is the screw used to mount the pcm and it goes into a plastic "screwholder" that is popped into the pcm mounting bracket... any ideas?? I'm gonna hit the garage and just start cleaning up other ground for the time being...
#14
08-19-2009, 05:08 PM
Okay, Some trucks are grounded through pins 11, 12 or 30 of the PCM connector, Guys at the dealership would somtimes take pin 30, 11 or 12 and tap to a good ground source. Problem was it ended up causing more problems than fixing anything! TPS is pin 22 IIRC.
Lets start with this and work down the diagnoses line!
TPS Voltage Range
1.0V +/- 0.2V at Idle
3.5V +/- 0.4V at Wide Open Throttle
TPS Linkage Adjustment Length 126.5 mm (5.0 in.)
CAUTION: Before attempting to test the Throttle Position Sensor (TPS) , verify the linkage adjustment dimension shown in the figure above. This dimension MUST be 126.5 mm (5.0 inches) BEFORE testing. For linkage adjustment procedures, refer to Throttle Linkage Adjustment.
CAUTION: Before testing the TPS, verify that the engine is set at correct low idle speed. Refer to Idle Speed Adjustment. This can be found in the Fuel Delivery and Air Induction system adjustments section.
After confirming the correct linkage adjustment and idle speed, proceed to the following:
Throttle Position Sensor Location
Attach a paper clip into the center terminal of the TPS electrical connector. Do not remove the connector from the TPS for this test.
Attach the positive lead of a voltmeter to this paper clip and the negative lead to a good ground.
Turn the ignition switch to the ON position. Do not start engine.
The voltage at the TPS center terminal should be 1.0 volt (+/- 0.2 volt) with linkage at idle position. The voltage at the wide open throttle position should be 3.5 volts (+/- 0.4 volts) . If voltage is not correct, proceed to adjusting linkage.
Throttle Lever Linkage Adjustment
The linkage rod connecting the throttle lever to the fuel injection pump lever is adjustable. To prevent damage to the ends of linkage, attach locking-type pliers to the flat located on the linkage rod before loosening locknuts.
Loosen the right-hand-threaded nut.
Loosen the left-hand-threaded nut.
Slowly rotate the flat on the linkage rod (lengthen or shorten) to achieve 1.0 volt (+/- 0.2 volts) on the voltmeter with the linkage in the idle position. With the throttle in the wide open position, voltage should be 3.5 volts (+/- 0.4 volts) . Do NOT lengthen or shorten the linkage rod more than 1 mm from the dimension shown. If voltage requirements cannot be met by linkage adjustment (125.6 to 127.6 mm) , replace the TPS.
Tighten both nuts after adjustment.
With the engine OFF, operate the throttle from accelerator pedal and check for throttle lever action and binding. Be sure throttle lever stop is against the low idle speed screw after throttle is released.
Be sure of wide open throttle (WOT) when accelerator pedal is pressed to the floor. This is checked by observing throttle lever breakover position. Proceed to the following:
Key OFF and engine OFF for this test.
Two people are needed for this test. From inside of the vehicle, press the accelerator pedal about half-way to the floor. Movement of both the throttle lever and throttle lever-to-injection pump lever linkage rod should be observed.
Continue to press the accelerator pedal to the floor. If throttle lever breakover is operating correctly, the throttle lever-to-injection pump lever linkage rod should have stopped moving while the throttle lever continues to move towards the rear of vehicle.
Again, check and verify low idle speed. Adjust if necessary.
Blown fuse.
Faulty overdrive solenoid.
Faulty wiring or connectors.
Faulty overdrive off switch.
Faulty engine controller.
Failed overdrive clutch.
Wrong overdrive piston bearing spacer selected.
Low overdrive pressure.
Lower valve body malfunction.
Lets start with this and work down the diagnoses line!
TPS Voltage Range
1.0V +/- 0.2V at Idle
3.5V +/- 0.4V at Wide Open Throttle
TPS Linkage Adjustment Length 126.5 mm (5.0 in.)
CAUTION: Before attempting to test the Throttle Position Sensor (TPS) , verify the linkage adjustment dimension shown in the figure above. This dimension MUST be 126.5 mm (5.0 inches) BEFORE testing. For linkage adjustment procedures, refer to Throttle Linkage Adjustment.
CAUTION: Before testing the TPS, verify that the engine is set at correct low idle speed. Refer to Idle Speed Adjustment. This can be found in the Fuel Delivery and Air Induction system adjustments section.
After confirming the correct linkage adjustment and idle speed, proceed to the following:
Throttle Position Sensor Location
Attach a paper clip into the center terminal of the TPS electrical connector. Do not remove the connector from the TPS for this test.
Attach the positive lead of a voltmeter to this paper clip and the negative lead to a good ground.
Turn the ignition switch to the ON position. Do not start engine.
The voltage at the TPS center terminal should be 1.0 volt (+/- 0.2 volt) with linkage at idle position. The voltage at the wide open throttle position should be 3.5 volts (+/- 0.4 volts) . If voltage is not correct, proceed to adjusting linkage.
Throttle Lever Linkage Adjustment
The linkage rod connecting the throttle lever to the fuel injection pump lever is adjustable. To prevent damage to the ends of linkage, attach locking-type pliers to the flat located on the linkage rod before loosening locknuts.
Loosen the right-hand-threaded nut.
Loosen the left-hand-threaded nut.
Slowly rotate the flat on the linkage rod (lengthen or shorten) to achieve 1.0 volt (+/- 0.2 volts) on the voltmeter with the linkage in the idle position. With the throttle in the wide open position, voltage should be 3.5 volts (+/- 0.4 volts) . Do NOT lengthen or shorten the linkage rod more than 1 mm from the dimension shown. If voltage requirements cannot be met by linkage adjustment (125.6 to 127.6 mm) , replace the TPS.
Tighten both nuts after adjustment.
With the engine OFF, operate the throttle from accelerator pedal and check for throttle lever action and binding. Be sure throttle lever stop is against the low idle speed screw after throttle is released.
Be sure of wide open throttle (WOT) when accelerator pedal is pressed to the floor. This is checked by observing throttle lever breakover position. Proceed to the following:
Key OFF and engine OFF for this test.
Two people are needed for this test. From inside of the vehicle, press the accelerator pedal about half-way to the floor. Movement of both the throttle lever and throttle lever-to-injection pump lever linkage rod should be observed.
Continue to press the accelerator pedal to the floor. If throttle lever breakover is operating correctly, the throttle lever-to-injection pump lever linkage rod should have stopped moving while the throttle lever continues to move towards the rear of vehicle.
Again, check and verify low idle speed. Adjust if necessary.
Blown fuse.
Faulty overdrive solenoid.
Faulty wiring or connectors.
Faulty overdrive off switch.
Faulty engine controller.
Failed overdrive clutch.
Wrong overdrive piston bearing spacer selected.
Low overdrive pressure.
Lower valve body malfunction.
#15
08-19-2009, 06:36 PM
I had checked everything that you listed already, except failed tranny parts; however, with a pot switch I was able to get it to shift into OD and everything worked correctly (it just wouldn't shift like I wanted it to bc voltage wasn't right... pot was not working correctly, but fooled the pcm pcm just enough)....
Right now I have the wires for the TPS located at the pcm, and I cut them (to make sure they weren't grounding somewhere inside the looms... will solder back together).... I "pinned" out the wires and here is what I read....
Power(pur/wht) to Ground (blk/blu): 5.01V
Ground (blk/blu) to Signal (org/wht): 4.96V...
that is with key in "on" position, eng off, with NO sensor hooked up (cause wires are cut about 4" from pcm.. and I'm sure I've got the right ones)...
I have cleaned-up all the grounds that I can find with no change.... I'm still not sure where the "ring terminal" is for the pcm ... the closest ground i find is behind the pass. side battery.... next closest are the ones on the driver's side inner fender....
As of right now the only thing I can think of is that something internally on the pcm has gone bad... however, this is hard for me to believe because everything else on the truck works perfectly...weird huh!?
Right now I have the wires for the TPS located at the pcm, and I cut them (to make sure they weren't grounding somewhere inside the looms... will solder back together).... I "pinned" out the wires and here is what I read....
Power(pur/wht) to Ground (blk/blu): 5.01V
Ground (blk/blu) to Signal (org/wht): 4.96V...
that is with key in "on" position, eng off, with NO sensor hooked up (cause wires are cut about 4" from pcm.. and I'm sure I've got the right ones)...
I have cleaned-up all the grounds that I can find with no change.... I'm still not sure where the "ring terminal" is for the pcm ... the closest ground i find is behind the pass. side battery.... next closest are the ones on the driver's side inner fender....
As of right now the only thing I can think of is that something internally on the pcm has gone bad... however, this is hard for me to believe because everything else on the truck works perfectly...weird huh!?
#17
08-19-2009, 07:45 PM
If you're talking about resistance from sensor to the pcm on each individual wire all 3 wires were under 1 ohm... I did find that I was getting continuity between pur/wht (supply) and org/wht (signal) at the ecm, but only when key was switched on... nothing between Gnd&Signal or Gnd&Supply with key on.... I took the pcm out and checked it for continuity with no power and it didn't show any continuity between any of the wires... if the circuit is bad it only shows when harness is plugged in and power is on... whichs makes sense to me.... i think!!?
#18
08-19-2009, 08:18 PM
What about someone with a PCM you could try out?
There's companys that will fix your PCM.
What about the resistance from ground on the PCM harness? The grounds I mentioned are not the only ones. There's a sensor ground or two also also.
will a scan tool show the PCM parameters on a 12v? I cant remember if it will show the TPS, It would be nice to know exactly what the PCM was thinking and working with as far as voltages. My concern with a PCM failure is 90% of failed pcm's are in the voltage regulator and thats about it. I've seen a few other failures. Would you have the ability to switch the tps sensor for another, I know you just put a new one in but I've seen failed parts come right out of the box? It's kinda hard for me to go further than I've gone without seeing everything right in front of me. My last thought on anything to try would be a used pcm or get yours checked.
There's companys that will fix your PCM.
What about the resistance from ground on the PCM harness? The grounds I mentioned are not the only ones. There's a sensor ground or two also also.
will a scan tool show the PCM parameters on a 12v? I cant remember if it will show the TPS, It would be nice to know exactly what the PCM was thinking and working with as far as voltages. My concern with a PCM failure is 90% of failed pcm's are in the voltage regulator and thats about it. I've seen a few other failures. Would you have the ability to switch the tps sensor for another, I know you just put a new one in but I've seen failed parts come right out of the box? It's kinda hard for me to go further than I've gone without seeing everything right in front of me. My last thought on anything to try would be a used pcm or get yours checked.
Last edited by mysterync; 08-19-2009 at 08:20 PM.
#19
08-20-2009, 11:29 PM
FYI... Installed a used PCM today... still 4.96V from signal to ground... truck is now throwing several codes.... 23, 24, 37.... 37 is TC solenoid or tranny temp sensor.... I'll probably throw a tranny temp sensor at it and see what happens, if that doesn't work I'll go ahead and pull the tranny and replace the TC solenoid (rear main seal is starting to leak just a little bit so I can throw one of those on it while I have the tranny out!!).... if none of those fixes the problem I'm not sure what I'll do... only thing left after that is to rewire the entire truck or say screw and get another truck, and take this old girl to the next level and make it a full-time sled puller!!! (I just wasn't quite ready to do that yet though)
#20
09-27-2011, 12:52 PM
