Had a P182e (Internal Mode Switch / Automatic ...switch indicator) recently which I replaced the IMS and everything looked good. Just got back from a 1.5 hr one-way trip and when I got to my location and was leaving the truck would not go into D, meaning the light would not light up which was similar to the p182e symptom. I got it to light up by turning off and back on and playing with the shifter and drove home. On the ride home the D would light up and then turn off, the truck had no noticeable issue but the indicator light kept flipping back and forth. There are no codes, code reader shows no issues but after I got home and shut off the truck and started it again and the issue remained sitting still, off and on sometimes.

Any ideas on what can be causing this? Low voltage on battery do something like this? idk, at my wits end.

Thanks,
Steve

 

So the transmission is shifting into/out of drive and there’s no harsh engagement or any driveability concerns, it’s just the indicator that’s blanking out?

The IMS signal is monitored by the PCM and data fed to the cluster. The PRNDL display is logic controlled within the cluster.

Double check that the electrical connections at the transmission are clean and tight. The lack of driveability concerns indicate the problem is isolated to the cluster.

 

With the loss of Drive, I believe you still have an issue with the IMS circuits. Make sure your shift cable is adjusted.

1. Ignition OFF, remove the automatic transmission fluid pan. Refer to Automatic Transmission Fluid, Fluid Pan and/or Filter Replacement.
2. Disconnect the B15 Transmission Internal Mode Switch connector at the Q8 Control Solenoid Valve Assembly. Ignition ON.
3. Verify the scan tool transmission control module Internal Mode Switch A/B/C/P parameter displays High High High High.
   • If High High High High is not displayedReplace the Q8 Control solenoid Valve Assembly.
     
   • If High High High High is displayed
4. Verify the scan tool Engine Control Module Park/Neutral Position Switch parameter displays In Gear.
   • If In Gear is not displayed
   1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
   2. Test for infinite resistance between the neutral start signal circuit and ground at the vehicle harness K20 Engine Control Module connector.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the K20 Engine Control Module.
   • If In Gear is displayed
5. Install a 3 A fused jumper wire between the low reference circuit terminal A and each signal circuit listed below one at a time at the Q8 Control Solenoid Valve Assembly:
   • Signal A – terminal E
   • Signal B – terminal D
   • Signal C – terminal C
   • Signal P – terminal B
6. Verify the scan tool Transmission Control Module A/B/C/P displays 1 Low and 3 High when a signal circuit is grounded.
   • If 1 Low and 3 High is not displayedReplace the Q8 control solenoid valve assembly.
     
   • If 1 Low and 3 High is displayed
7. Connect a 3 A fused jumper wire between Park/Neutral switch signal circuit terminal F and low reference circuit terminal A at the Q8 Control Solenoid Valve Assembly.
8. Verify the scan tool engine control module Park/Neutral Position Switch parameter displays Park/Neutral.
   • If Park/Neutral is not displayed
   1. Ignition OFF, disconnect the connector at the K20 Engine Control Module.
   2. Test for less than 2 Ω in the signal circuit wire end to wire end.
      • If 2 Ω or greater, repair the open/high resistance in the wire circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
   • If Park/Neutral is displayed
9. Replace the B15 Transmission Internal Mode Switch.
10. Hope this helps.

 

Make sure you search your vehicle TSB's . GM had some issues with these before.

 

Didn't see any TSB's for P182E. I have found the 6L80/6L90's loose Drive range !st gear and no fault code due to a worn #1 check ball, but you have reverse and will have all other fwd gears and PRNDL works properly.