Mystery switch sets p0122

[IBMobile]

I put a mystery switch in the shifter, thank you me78569. The momentary switch is used to trip a 'switching' relay that turns on a light at the A-post next to the trans temp gauge and all so closes a 'grounding' relay that grounds the torque converter lockup solenoid. Terminal 85 of the switching relay is grounded through terminal 1 of the brake light switch which is also a ground for the ABS controller.

 

When I engage the lock up everything is ok , then manually lock out over drive to down shift to 3ed. The check engine light comes on. There is no up shift to over drive until the lockup solenoid is ungrounded. The code that is set is p0122 throttle position sensor/switch A circuit low input, the APPS.

 

Does anyone see what would cause this condition or am I bound to use a single switch to ground for lock up.

 

Edited April 29, 2015 by IBMobile

[Mopar1973Man]

I'm scratching my head...

 

Monitor & Set Conditions

Accelerator Pedal Position Sensor (APPS) voltage is monitored when engine is running. DTC may be stored if low voltage is detected on APPS signal circuit or low voltage is detected between Engine Control Module (ECM) and Powertrain Control Module (PCM).

Possible Causes

• 5-volt Supply At APPS Shorted To ECM Sensor Ground
• APPS Signal Circuit Shorted To ECM Sensor Ground
• 5-volt Supply To Ground
• APPS Signal Circuit Shorted To Ground
• APPS Signal Circuit Open To ECM
• PCM (APPS) Short To ECM Sensor Ground
• ECM (APPS) To PCM (APPS) Circuit Shorted
• ECM (APPS) To PCM (APPS) Circuit Open
• Short To ECM Sensor Ground
• Accelerator Pedal Position Sensor (APPS)
• Engine Control Module
• Powertrain Control Module

[IBMobile]

I can set the code with the key on engine not running. I'm going to work this problem backwards by just grounding the lockup solenoid first. If no problem then adding the  'grounding' relay and powering up the green wire. If no problem then add the 'switching' relay but remove the red/yellow wire from the pink wire at the brake switch and run it straight to ground.

[Me78569]

wow that is odd.  Let me mull it over.

Let me clearify for my thought process

-using the lockup switch alone works fine

-Code/light happens when you disable OD

- once in 3rd with the tc locked you cannot upshift ( unclick OD disable right?) until you unlock the TC?

 

Side note I was thinking about adding a TC lockup light also. 

[IBMobile]

-using the lockup switch alone works fine

-Code/light happens when you disable OD

- once in 3rd with the tc locked you cannot upshift ( unclick OD disable right?) until you unlock the TC?

 

Side note I was thinking about adding a TC lockup light also. 

yes, this is what's happening with no direct correlation between the APPs code and O/D lock out.

[AGPTurbo]

I know from doing mine I threw a code on a 2002 without a 33 ohm resistor and I did a ton of reading while trying to solve it and remember that anyone who installed an indicator light of any type- even a lighted switch had trouble.

Edited April 29, 2015 by AGPTurbo

[Mopar1973Man]

IBMobile's design has the light outside the circuit for the switch.

 

I understand why the lighted switch doesn't work because the light in the switch is on the same circuit as the torque converter clutch and drawing voltage and currant on that same circuit. Just like you can use lighted switch on the high idle mod or the MPG fooler because the light draws on the 5 volt signal and would mess up the voltage required. This why the rotary switch works well in Yankneck's design because a separate switch drove the light while another switch drove the resistors and sensor leads. So now looking at IBMobile's design it should work but the relationship between the APPS sensor and the transmission torque converter clutch is long way away from each other.

[IBMobile]

I found the problem, owner/installer dumb a$$ mistake  . Working it backwards I grounded the yellow wire from the PCM/solenoid, then locked out the O/D. The CEL came on. Check where I spliced in and saw that I spliced into an orange/black wire at C3 and not the orange/black at C2 for the PCM.Thank you for trying to help the hapless .

 

It works great now  . locks up for 3ed and 4th, has 3-4 up shifts, light is on when system is engaged, and the system turns off when either the brake peddle or momentary switch is pressed. This set up cost less than 20$ with used relays and wire from a junkyard, bought the led light at Fry's and the switch on E-Bay.

 

[Mopar1973Man]

Maybe you should go into production. I'll gladly sell them here on the Mopar1973Man.Com site.