1993 Tans Port Codes & Shifting Problems
jnrwiles
12-04-2005, 04:03 PM
I have a few questions ? I have a 1993 Pontiac Trans Port 3.8 4 speed trans. I am getting some codes and have no 3rd or 4th gear. The codes i am getting are 21,22,23,43 and 56. I know that codes 21 and 22 are the tp code 23 is the iac, 43 is the esc and code 56 is the quad driver.Would any of these keep the tranny from shifting from 3rd to 4th ? If so could someone let me know which one to try first ? The car runs very well and doesnt have much miss for a 170,000 mile vehicle but when cold it sounds like the timing is off.Also i was told could be the shift solenoids. When replacing those do i have to pull the side pan from the tranny to access them ? Thanks
maxwedge
12-04-2005, 04:39 PM
Quad driver could be in the shift solenoid circuit, this needs to be scanned with a trans capable scanner to confirm solenoid operation, at the extreme a tps stuck on full throttle readings could delay all the upshifts.
LMP
12-04-2005, 06:21 PM
COdes 21 and 22 DO inhibit 4th, tcc and cruise.
www.avigex.ca/xport/dtc21.jpg
www.avigex.ca/xport/dtc22.jpg
Clear this first. www.avigex.ca/xport/maf.jpg
www.avigex.ca/xport/tpsloc.jpg
The rest can wait:
43 is knock sensor: no big deal..but retards timing 10 degrees...
www.avigex.ca/xport/dtc43.jpg
23 is intake air temperature (low).(IAT, not IAC) ..possibly disconnected. Has no great consequence - acts on timing too..
56: often a consequence of other failures (possibly from 21/22) Wait till this TPS is reset, clear all codes (disconnect battery 10 minutes) and check again later.
www.avigex.ca/xport/dtc21.jpg
www.avigex.ca/xport/dtc22.jpg
Clear this first. www.avigex.ca/xport/maf.jpg
www.avigex.ca/xport/tpsloc.jpg
The rest can wait:
43 is knock sensor: no big deal..but retards timing 10 degrees...
www.avigex.ca/xport/dtc43.jpg
23 is intake air temperature (low).(IAT, not IAC) ..possibly disconnected. Has no great consequence - acts on timing too..
56: often a consequence of other failures (possibly from 21/22) Wait till this TPS is reset, clear all codes (disconnect battery 10 minutes) and check again later.
jnrwiles
12-05-2005, 07:53 AM
I am going out today to check the tps out. Do you happen to know th ohm's on the tps ? Thanks
LMP
12-05-2005, 09:35 AM
What counts is having a continuous contact between pot wiper and resistance track. At times the wiper contact gets dirty and gives 0V- specially at point where throttle is most of the time - and I have been able to make some WD40 enter the pot and clean the track..and keep the original TPS. But the track can be broken too. I think the pot must be 10k but the exact value 5k, 10k, 20k does not matter as long as there is a linearly or continuous voltage increase (pin B) from one end of the travel to the other end as throttle is slowly depressed, thus about .5 to 4.5 V. A broken track would give either the lo end or the hi end voltage.
onerchprk
02-17-2006, 08:57 AM
Ok i replaced the tps and no good so i changed the shift solenoids but still no 3rd or 4th gears. Also i cannot check the codes as my instrument panel took a dump(only speedo and battery gauge works). I have also read something about a bad ground on the solenoids but could someone maybe explain how to fix the ground thing or rig it just to do a test run? Thanks
LMP
02-17-2006, 12:09 PM
Ok i replaced the tps and no good so i changed the shift solenoids but still no 3rd or 4th gears. Also i cannot check the codes as my instrument panel took a dump(only speedo and battery gauge works). I have also read something about a bad ground on the solenoids but could someone maybe explain how to fix the ground thing or rig it just to do a test run? Thanks
..I searched through your previous posts and could not find your reference to this 3rd and 4th gear problem....NOtice that 3rd gear condition is both solenoids off. ANyway, look at these:
www.avigex.ca/xport/34shift.jpg
www.avigex.ca/xport/transaxle.jpg
www.avigex.ca/xport/transaxleconnector.jpg
www.avigex.ca/xport/3rdgear.jpg
However I have no useful opinion on thet problem. I'll see if some other page in the service manual relates to such problem and add it to list if any.
..I searched through your previous posts and could not find your reference to this 3rd and 4th gear problem....NOtice that 3rd gear condition is both solenoids off. ANyway, look at these:
www.avigex.ca/xport/34shift.jpg
www.avigex.ca/xport/transaxle.jpg
www.avigex.ca/xport/transaxleconnector.jpg
www.avigex.ca/xport/3rdgear.jpg
However I have no useful opinion on thet problem. I'll see if some other page in the service manual relates to such problem and add it to list if any.
onerchprk
02-24-2006, 10:28 AM
Sorry it was posted under the wifes account jnrwiles
Automotive Network, Inc., Copyright ©2026
