2015 RAM 2500 Cummins - Service Electronic Throttle Control - Code P0108 / P007D?

[Awilson815]

Hello, I recently replaced the front and rear fuel filters.

After priming and the engine continuously turned over would start and then die.

I noticed the cap in the front canister was not completely sealed and was leaking.

I've had issues with the oem cap, so I replaced it with a billet cap that is now correctly sealing.

After attempting to crank it again, I noticed the lighting bolt light was now on.

Everything was fine until the fuel filter changed.

I think all the cranking possibly caused this.

After some research, I kept seeing things about the MAP sensor needing to be cleaned or replaced.

I cleaned the map sensor and reinstalled it with no luck.

I bought a cheap map sensor on Amazon that got rid of the service electronic throttle control light, but P0108 remained on and was now showing P0087 for low fuel rail pressure.

Assuming it was another junk sensor, I possibly ordered the specific one for my truck from Cummins.

I received that sensor yesterday and installed it.

Now the Service electronic throttle control light and codes P0108 and P007D are back on.

The IAT sensor has been removed and cleaned.

233k miles on the truck right now.
Throttle Control Valve has been removed.
EFI Live - Anarchy Mercenary.
Bank's Cold Air intake.
Full delete minus grid heater.

Could a clogged grid heater be the culprit?

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[AK Bob]

I have attached the troubleshooting information for both of your current codes.

I don’t think a clogged grid heater will cause these codes.

I would monitor the IAT with a tuner monitor or a scan tool, which should read close to ambient temperature when cold (+/- 20*F).

If the IAT sensor reads well, check the 5V reference, signal, and ground at the MAP sensor as described in P0108.

I hope this is helpful; please keep us posted.

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[Awilson815]

Thanks for the reply!

I will do those checks and update once I get home later today.

Could the fuel filter change trigger any of these issues?

I used a belt wrench to remove the OEM canister cap and may have bumped the hand into that map harness while trying to free the cap.

Also, the Evic digital boost gauge and the edge CTS3 are not reading any boost pressure; however, a boost is definitely being made.

The exhaust brake is slow to engage, typically about 4 seconds after letting off the throttle. CTS3 monitor indicates the TC is locked up when letting off the throttle but delayed exhaust break engagement.

*Turbo actuator was replaced a year ago.

Aside from those codes, the truck is running very smoothly.

Thanks again for your help!

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[AK Bob]

Thanks for the reply!

I will do those checks and update once I get home later today.

Could the fuel filter change trigger any of these issues?

I used a belt wrench to remove the OEM canister cap and may have bumped the hand into that map harness while trying to free the cap.

Also, the Evic digital boost gauge and the edge CTS3 are not reading any boost pressure; however, a boost is definitely being made.

The exhaust brake is slow to engage, typically about 4 seconds after letting off the throttle. CTS3 monitor indicates the TC is locked up when letting off the throttle but delayed exhaust break engagement.

*Turbo actuator was replaced a year ago.

Aside from those codes, the truck is running very smoothly.

Thanks again for your help!

Yes, you may have damaged the MAP harness.

I would give it a good inspection in that area.

The reference, signal, and ground checks will also confirm any issues with the harness.

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[Awilson815]

I've checked over the MAP Harness plug and pigtail for damage and did not see any.

I went through the diagnostics you sent and got to set 4 but could not see any resistance; the screen remained on OL and did not read anything.

(I used a Klein 420MM). There is a chance I did something wrong there, and I'm not the most versed in using a multimeter outside of voltage tests.

I've reconnected the PCM and MAP Plug cleared the DTCs turned off the ignition unplugged the MAP sensor turned the ignition on, and now had P0107 along with P0108 and P007D.

Cleared DTCs, and the same P0108 and P007D remain.

I'm stumped.

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[AK Bob]

I've checked over the MAP Harness plug and pigtail for damage and did not see any.

I went through the diagnostics you sent and got to set 4 but could not see any resistance; the screen remained on OL and did not read anything.

(I used a Klein 420MM). There is a chance I did something wrong there, and I'm not the most versed in using a multimeter outside of voltage tests.

I've reconnected the PCM and MAP Plug cleared the DTCs turned off the ignition unplugged the MAP sensor turned the ignition on, and now had P0107 along with P0108 and P007D.

Cleared DTCs, and the same P0108 and P007D remain.

I'm stumped.

In step 4, they measure the resistance of the sensor ground wire (K916) by disconnecting the MAP sensor and the C1 connector at the PCM and looking for continuity (less than 5 Ohms).

I suspect you disconnected the MAP sensor harness and are trying to measure the resistance between the sensor and the harness plug, which will show an open circuit or “OL” on the meter.

Since the PCM grounds K916, you could leave the PCM C1 connected, use the battery-positive test light, and touch the probe to the K916 wire on the MAP sensor harness side.

If the test light illuminates, then the circuit is good.

CAUTION do not make your own test light with a bulb unless you know what you are doing; too much current draw will fry your PCM.

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[Awilson815]

I have a Klein Test light (69133 model).

Would that be safe to use?

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[AK Bob]

I have a Klein Test light (69133 model).

Would that be safe to use?

Not sure what the current draw of the bulb in the handle is.

You don’t want to draw more than 150ma at 12V to be safe.

You could check between the positive battery post and ground with it and measure the current draw with your multimeter in series.

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[Awilson815]

Given my minimal knowledge of electrical diagnostics, this is probably the point where I need to take it to an actual mechanic.

Thanks again for your help, though!

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[AK Bob]

Given my minimal knowledge of electrical diagnostics, this is probably the point where I need to take it to an actual mechanic.

Thanks again for your help, though!

You are welcome anytime.

I understand if you are not comfortable performing some of these tests.

Please keep us posted on the final fix and the cause of your trouble codes.

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