Jump to content

Traction control off/limp mode/DTC C121C-00 Torque Request Denied


Recommended Posts

Happy Sunday everyone! 
 

A week ago I began having an intermittent issue on my 2014 2.4L Journey SE. 
• gauge indicator comes on showing the traction control is off

• cannot turn traction control back on with dash button

• cruise control doesn’t work when the traction control is off

• car “stutters” when attempting to accelerate

• check engine light on- DTC P0340 (could be very old code from head gasket fix last year)

• DTC shows C121C-00 Torque Request Signal Denied

• ABS dash light indicator is NOT on

• we’ve cleared all codes in attempt to reset- doesn’t work

• visual check shows no frayed wires or cables


My stepdad is a retired mechanic so now limited on diagnostic ability but we are able to make any/all repairs if possible. Everything I’m finding mentions likely failure of the ABS but I know my Journey has a direct TCS so it doesn’t go through the ABS (which makes sense the light isn’t on). 
 

With all this said, I have 2 questions I can’t find direct answers to: 

1. Is the TCS off issue directly related to the DTC code C121C-00?

2. Where in the world do we start with diagnosing? Spend the money to change out sensors? Jump to replacing the module? 
 

Any/all recommendations are appreciated! 
 

Link to comment
Share on other sites

I would suggest going after the P0340 code first, if engine{especially a 4 cyl.} is not operating properly or even intermittently, the PCM will deny trac. control and cruise control.

In my understanding, you are correct in thought of it not being a wheel speed sensor or you would have codes for it. You have a high enough level scanner since it read the C121C-00 code.

Link to comment
Share on other sites

On 7/21/2024 at 6:43 PM, 5rebel9 said:

I would suggest going after the P0340 code first, if engine{especially a 4 cyl.} is not operating properly or even intermittently, the PCM will deny trac. control and cruise control.

In my understanding, you are correct in thought of it not being a wheel speed sensor or you would have codes for it. You have a high enough level scanner since it read the C121C-00 code.

Thank you so much. 
 

I did confirm with my stepdad that the P0340 code was a permanent code that he was never able to clear after we replaced my head gasket last year. 
 

If we disregard that code, is there a way to diagnose the C121C-00 by process of elimination? 

Link to comment
Share on other sites

Thanks for posting these diagnostic charts @Dean H!  This should help this member out of their problem nicely!

I don't have ready access to such materials, but from my own experience would have followed such instructions anyway. But I could not explain and detail well enough to somebody else what to do. 

Keep up the great job here on the forum!

Link to comment
Share on other sites

  • 2 months later...
On 7/24/2024 at 3:03 PM, 5rebel9 said:

Thanks for posting these diagnostic charts @Dean H!  This should help this member out of their problem nicely!

I don't have ready access to such materials, but from my own experience would have followed such instructions anyway. But I could not explain and detail well enough to somebody else what to do. 

Keep up the great job here on the forum!

Yes, thank you so much @Dean H
 

I’m so sorry I’m several months late posting- lots of life issues popped up. 
 

Long story short- I now have more problems than I started with. We replaced both sensors, then the Journey died while accelerating from a stoplight. It started back up and I thought it might have been a fluke/bad gas, but when I got to my parents’ house to pick up my daughter, it would not shift when starting it back up. 
 

Presently, it does not have reverse or drive, 1st gear is nonexistent, 2nd/3rd gear works BUT the power brakes do not work. 
 

Code at the time was showing P2135 and P0221. We replaced the Throttle Control Body, no difference. 
 

We replaced the battery thinking maybe it was going bad and making the electronics go crazy- no luck but now it only shows P2173, P0171, and P0507. 
 

The current lights on the dash show traction control off, the electrical lightning bolt/battery (alternating between the two), and of course- check engine. It starts right up without hesitation or issues. 
 

I checked the PCM fuse just because, why not- and the fuse is good. 
 

What’s really stumping us is no brakes, random transmission gears, and of course the new codes. Could this be a bad PCM at this point?

Link to comment
Share on other sites

28 minutes ago, Dean H said:

Life issues.  Say no more, I know.

 

So what all have you replaced

so far?

It’s been a never ending rollercoaster, dear lord! 2025 can’t get here soon enough.  

 

So we’ve replaced: 

Battery

Throttle Body and gasket

Cam Position Sensors (from previous post)

Fuses are good

Wiring is good

 

 

 

 

Link to comment
Share on other sites

You need to have a bi-directional scan tool.

 

That can communicate with all the modules and test individual components.

 

Perform relearn procedures.

 

I have this one-

 

LAUNCH X431 CRP919EBT Elite... https://www.amazon.com/dp/B0C68BKGN3?ref=ppx_pop_mob_ap_share

 

 

Please scan for codes and tell me exactly. What they all are right now.

 

 

Edited by Dean H
Link to comment
Share on other sites

You have an engine vacuum leak.

 

The no power brake booster and these codes are vacuum leak related.

 

Trace vacuum lines from the map sensor to the brake booster and the engine source.

 

P2173-

HIGH AIRFLOW/VACUUM LEAK DETECTED (SLOW ACCUMULATION)

 

Possible Causes

 

VACUUM LEAK

 

RESTRICTION IN THE EXHAUST SYSTEM

 

INTERNAL ENGINE MECHANICAL COMPONENTS

 

RESISTANCE IN THE 5-VOLT SUPPLY CIRCUIT

 

RESISTANCE IN THE MAP SIGNAL CIRCUIT

 

RESISTANCE IN MAP SENSOR GROUND CIRCUIT

 

MAP SENSOR

 

POWERTRAIN CONTROL MODULE (PCM)

 

Edited by Dean H
Link to comment
Share on other sites

P0171-FUEL SYSTEM 1/1 LEAN

 

Possible Causes

 

RESTRICTED FUEL SUPPLY LINE

 

FUEL PUMP INLET STRAINER PLUGGED

 

FUEL PUMP MODULE

 

02 SIGNAL CIRCUIT

 

02 RETURN CIRCUIT

 

02 SENSOR

 

MAP SENSOR

 

ECT SENSOR

 

ENGINE MECHANICAL

 

FUEL FILTER/PRESSURE REGULATOR

 

POWERTRAIN CONTROL MODULE (PCM)

Link to comment
Share on other sites

On 7/21/2024 at 5:18 PM, rocker.nurse said:

Happy Sunday everyone! 
 

A week ago I began having an intermittent issue on my 2014 2.4L Journey SE. 
• gauge indicator comes on showing the traction control is off

• cannot turn traction control back on with dash button

• cruise control doesn’t work when the traction control is off

• car “stutters” when attempting to accelerate

• check engine light on- DTC P0340 (could be very old code from head gasket fix last year)

• DTC shows C121C-00 Torque Request Signal Denied

• ABS dash light indicator is NOT on

• we’ve cleared all codes in attempt to reset- doesn’t work

• visual check shows no frayed wires or cables


My stepdad is a retired mechanic so now limited on diagnostic ability but we are able to make any/all repairs if possible. Everything I’m finding mentions likely failure of the ABS but I know my Journey has a direct TCS so it doesn’t go through the ABS (which makes sense the light isn’t on). 
 

With all this said, I have 2 questions I can’t find direct answers to: 

1. Is the TCS off issue directly related to the DTC code C121C-00?

2. Where in the world do we start with diagnosing? Spend the money to change out sensors? Jump to replacing the module? 
 

Any/all recommendations are appreciated! 
 

since the abs light is off it,shouldn't  be the abs uni,t but that unit is considered a priority software code and can only be diagnosed with the higher quality scanners, I just had my abs unit replaced thur the dealership with a long backorder wait on the unit but mine had the c2200-40 code   sometimes the dealership which is more expensive can come out cheaper and quicker than just throwing parts at the journey..good luck and please report back on what you find to be the problem and the fix for others 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...