Jump to content

Recommended Posts

Posted

i’m trying to get some help with my 2020 2500 HD it’s not covered under the recall and I’m getting all three switches on the fob the dash and the tailgate to actuate the relay on the dash but the gate still is not dropping wondering if anybody else has had similar issues and if I could get a little help here, I would appreciate it the dealer stating it’s not covered under the current recalls thank you for any help 

Posted
26 minutes ago, Gabe montoya said:

i’m trying to get some help with my 2020 2500 HD it’s not covered under the recall and I’m getting all three switches on the fob the dash and the tailgate to actuate the relay on the dash but the gate still is not dropping wondering if anybody else has had similar issues and if I could get a little help here, I would appreciate it the dealer stating it’s not covered under the current recalls thank you for any help 

 

 

The recall was for the switch in the gate failing causing the gate to open unwanted.  You have a different issue, it won't drop.

 

Needs a tailgate actuator, the piece under the access panel that the latch rods attach to.  Pretty common failure on 19-20 1500s and 2020 HDs.  

Posted (edited)
11 minutes ago, Gabe montoya said:

I have used a power probe and it actuates fine. I only get.5 volts to the actuator when any of the buttons are pressed 

 

.  

Edited by newdude
Posted (edited)
29 minutes ago, Gabe montoya said:

I have used a power probe and it actuates fine. I only get.5 volts to the actuator when any of the buttons are pressed 

 

 

TSB - 20-NA-40 1..3 (nhtsa.gov)

 

Some customers may comment on the power endgate may not unlatch or drop on first try, or under some conditions, it may not open at all.

 

Cause

The cause of the condition may be a combination of excessive spring force and low available voltage, which may cause the latch actuator to fail to function.

 

Upon verifying the condition, replace the pickup box endgate lock actuator (2) with an improved design service part. Refer to Pickup Box Endgate Lock Actuator Replacement (Power) in SI.

Edited by newdude
Posted

Thank you .Do have access to see what the voltage to the end gate actuator from the relay is.the TSB talks about low voltage to the actuator but never stated what it should be.thanks again for your input and time.

Posted (edited)
15 minutes ago, Gabe montoya said:

Thank you .Do have access to see what the voltage to the end gate actuator from the relay is.the TSB talks about low voltage to the actuator but never stated what it should be.thanks again for your input and time.

 

Endgate Release Operation (Without MutiPro Tailgate Option)
 
Interior Endgate Release Switch

The body control module monitors the voltage level of the endgate unlatch signal circuit so that when the switch is pressed contacts within the switch closes providing a ground path for the endgate unlatch signal circuit, the voltage within the signal circuit is pulled low, the body control module will detect the voltage drop and if the passenger doors are unlocked, will energize the pickup box endgate unlatch relay.

 

Exterior Endgate Release Switch

The body control module monitors the status of the vehicle doors, if the doors are locked the body control module will ignore the request from the exterior pickup box endgate control switch. If the passenger doors have been commanded to unlock, pressing the exterior pickup box endgate control switch will close contacts within the switch and provide a ground path for the endgate unlatch signal circuit, the body control module will detect the voltage drop and will energize the pickup box endgate unlatch relay.

 

If the vehicle has been equipped with the passive keyless entry system and the keyless entry transmitter is within 3 feet (1 meter) of the endgate, pressing the exterior pickup box endgate control switch will also function in the same manner but without unlocking the passenger doors. Refer to Keyless Entry System Description and Operation for more information on the passive keyless entry system.

 

Pickup Box Endgate Unlatch actuator

When body control module receives a endgate release command from the exterior pickup box endgate control switch, the body control module applies brief pulse of voltage to the pickup box endgate unlatch relay control circuit, which energizes the coil side of the relay. The switch side of the pickup box endgate unlatch relay then momentarily closes, supplying a brief pulse of battery positive voltage to the pickup box endgate unlatch actuator. The pickup box endgate unlatch actuator is continuously grounded and when it receives the voltage pulse, it will become energized and the latch will activate releasing the endgate so that it may be manually lowered to an open position.

Circuit/System Verification
  1. Ignition » On / Vehicle » In Service Mode
  2. Operate the component: S159E Pickup Box Endgate Control Switch - Exterior » Pressed

    Verify the component turns On and Off: E42 Tail Lamp Assembly

    • If the component does not turn On and Off

      Refer to: Circuit/System Testing — Test 1

    • If the component turns On and Off
  3. Operate the component: S159E Pickup Box Endgate Control Switch - Exterior » Pressed

    Verify the component produces a clicking sound: A99C Pickup Box Endgate Latch - Center

    • If a click cannot be heard or felt

      Refer to: Circuit/System Testing — Test 2

    • If a click can be heard or felt
  4. Operate the component: S157 Pickup Box Endgate Unlatch Switch @ S86 Vehicle Stability Control Switch » Pressed

    Verify the component produces a clicking sound: A99C Pickup Box Endgate Latch - Center

    • If a click cannot be heard or felt

      Refer to: Circuit/System Testing — Test 3

    • If a click can be heard or felt
  5. All OK.
Circuit/System Testing
Test 1

Note: It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems » Off
  2. Disconnect the electrical connector: S159E Pickup Box Endgate Control Switch - Exterior
  3. Test for less than 10 Ω between the test points: Ground circuit terminal 2 & Ground
    • If 10 Ω or greater
    1. Ground Connection » Disconnect
    2. Test for less than 2 Ω between the test points: Ground circuit terminal 2 @ Component harness & Ground Connection
      • If 2 Ω or greater » Repair the open/high resistance in the circuit.
      • If less than 2 Ω » Repair the open/high resistance in the ground connection.
    • If less than 10 Ω
  4. Ignition » On / Vehicle » In Service Mode
  5. Momentarily connect a 3 A fused jumper wire between the test points: Signal circuit terminal 1 & Ground circuit terminal 2

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: A99C Pickup Box Endgate Latch - Center

    • If the component does not turn On and Off
    1. Ignition/Vehicle » Off & Remove » Jumper wire(s)
    2. Disconnect the electrical connector: K9 Body Control Module
    3. Ignition » On / Vehicle » In Service Mode
    4. Test for less than 1 V between the test points: Signal circuit terminal 1 @ Component harness & Ground
      • If 1 V or greater » Repair the short to voltage on the circuit.
      • If less than 1 V
    5. Ignition/Vehicle » Off
    6. Test for infinite resistance between the test points: Signal circuit terminal 1 @ Component harness & Ground
      • If less than infinite resistance » Repair the short to ground on the circuit.
      • If infinite resistance
    7. Test for less than 2 Ω between the test points: Signal circuit terminal 1 @ Component harness & Terminal 14 X6 @ Control module harness
      • If 2 Ω or greater » Repair the open/high resistance in the circuit.
      • If less than 2 Ω » Replace the component: K9 Body Control Module
    • If the component turns On and Off
  6. Test or replace the component: S159E Pickup Box Endgate Control Switch - Exterior
Test 2
  1. Ignition/Vehicle » Off
  2. Remove the component: KR191L Pickup Box Endgate Latch Relay - Left & KR191R Pickup Box Endgate Latch Relay - Right
  3. Test for less than 10 Ω between the test points:
    • Ground circuit terminal 21 & Ground @ KR191L Pickup Box Endgate Latch Relay - Left
    • Ground circuit terminal 8 & Ground @ KR191R Pickup Box Endgate Latch Relay - Right
    • Ground circuit terminal 17 & Ground @ KR191R Pickup Box Endgate Latch Relay - Right
    • If 10 Ω or greater
    1. Ground Connection » Disconnect
    2. Test for less than 2 Ω between the test points:
      • Ground circuit terminal 21 @ KR191L Pickup Box Endgate Latch Relay - Left & Ground Connection
      • Ground circuit terminal 8 @ KR191R Pickup Box Endgate Latch Relay - Right & Ground Connection
      • Ground circuit terminal 17 @ KR191R Pickup Box Endgate Latch Relay - Right & Ground Connection
      • If 2 Ω or greater » Repair the open/high resistance in the circuit.
      • If less than 2 Ω » Repair the open/high resistance in the ground connection.
    • If less than 10 Ω
  4. Connect a test lamp between the test points:
    • Control circuit terminal 1 & Ground circuit terminal 21 @ KR191L Pickup Box Endgate Latch Relay - Left
    • Control circuit terminal 10 & Ground circuit terminal 17 @ KR191R Pickup Box Endgate Latch Relay - Right
  5. Ignition » On / Vehicle » In Service Mode
  6. Operate the component: S159E Pickup Box Endgate Control Switch - Exterior » Pressed

    Verify the test lamp turns On and Off.

    • If the test lamp is always Off
    1. Ignition/Vehicle » Off & Remove » Test lamp
    2. Disconnect the electrical connector: K9 Body Control Module
    3. Test for infinite resistance between the test points:
      • Control circuit terminal 1 @ Relay Socket & Ground
      • Control circuit terminal 10 @ Relay Socket & Ground
      • If less than infinite resistance » Repair the short to ground on the circuit.
      • If infinite resistance
    4. Test for less than 2 Ω between the test points:
      • Control circuit terminal 1 @ Relay Socket & Terminal 11 X5 @ Control module harness
      • Control circuit terminal 10 @ Relay Socket & Terminal 9 X5 @ Control module harness
      • If 2 Ω or greater » Repair the open/high resistance in the circuit.
      • If less than 2 Ω » Replace the component: K9 Body Control Module
    • If the test lamp is always On
    1. Ignition/Vehicle » Off & Remove » Test lamp
    2. Disconnect the electrical connector: K9 Body Control Module
    3. Ignition » On / Vehicle » In Service Mode
    4. Test for less than 1 V between the test points:
      • Control circuit terminal 1 @ Relay Socket & Ground
      • Control circuit terminal 10 @ Relay Socket & Ground
      • If 1 V or greater » Repair the short to voltage on the circuit.
      • If less than 1 V » Replace the component: K9 Body Control Module
    • If the test lamp turns On and Off
  7. Verify a test lamp turns On between the test points: B+ circuit terminal 20& Ground
    • If the test lamp does not turn On and the circuit fuse is OK
    1. Ignition/Vehicle » Off & Remove » Test lamp
    2. Test for less than 2 Ω between the test points: B+ circuit terminal 20@ Relay Socket & Output terminal @ F17DL Fuse
      • If 2 Ω or greater » Repair the open/high resistance in the circuit.
      • If less than 2 Ω » Verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not turn On and the circuit fuse is open
    1. Ignition/Vehicle » Off & Remove » Test lamp
    2. Test for infinite resistance between the test points: B+ circuit terminal 20& Ground
      • If less than infinite resistance » Repair the short to ground on the circuit.
      • If infinite resistance
    3. Disconnect the electrical connector: A99C Pickup Box Endgate Latch - Center
    4. Test for infinite resistance between the test points: Control circuit terminal 2 @ Relay Socket & Ground
      • If less than infinite resistance » Repair the short to ground on the circuit.
      • If infinite resistance
    5. Replace the component: F17DL Fuse
    6. Install the component: KR191L Pickup Box Endgate Latch Relay - Left & KR191R Pickup Box Endgate Latch Relay - Right
    7. Connect a test lamp between the test points: Control circuit terminal 1 & Control circuit terminal 2
    8. Ignition » On / Vehicle » In Service Mode
    9. Operate the component: S159E Pickup Box Endgate Control Switch - Exterior » Pressed

      Verify the test lamp turns On and Off.

      • If the test lamp does not turn On and Off » Test or replace the component: KR191L Pickup Box Endgate Latch Relay - Left or KR191R Pickup Box Endgate Latch Relay - Right
      • If the test lamp turns On and Off » Test or replace the component: A99C Pickup Box Endgate Latch - Center
    • If the test lamp turns On
  8. Ignition/Vehicle & All vehicle systems » Off
  9. Install the component: KR191L Pickup Box Endgate Latch Relay - Left & KR191R Pickup Box Endgate Latch Relay - Right
  10. Disconnect the electrical connector: A99C Pickup Box Endgate Latch - Center
  11. Connect a test lamp between the test points: Control circuit terminal 1 & Control circuit terminal 2
  12. Ignition » On / Vehicle » In Service Mode
  13. Operate the component: S159E Pickup Box Endgate Control Switch - Exterior » Pressed

    Verify the test lamp state:

    Not Pressed = Test lamp Off

    Pressed = Test lamp On

    • If not the specified state
    1. Ignition/Vehicle » Off & Remove » Test lamp
    2. Remove the component: KR191L Pickup Box Endgate Latch Relay - Left & KR191R Pickup Box Endgate Latch Relay - Right
    3. Ignition » On / Vehicle » In Service Mode
    4. Test for less than 1 V between the test points:
      • Control circuit terminal 1 @ Component harness & Ground
      • Control circuit terminal 2 @ Component harness & Ground
      • If 1 V or greater » Repair the short to voltage on the circuit.
      • If less than 1 V
    5. Ignition/Vehicle » Off
    6. Test for infinite resistance between the test points:
      • Control circuit terminal 1 @ Component harness & Ground
      • Control circuit terminal 2 @ Component harness & Ground
      • If less than infinite resistance » Repair the short to ground on the circuit.
      • If infinite resistance
    7. Test for less than 2 Ω between the test points:
      • Control circuit terminal 1 @ Component harness & Terminal 2 @ Relay Socket
      • Control circuit terminal 2 @ Component harness & Terminal 18 @ Relay Socket
        • If 2 Ω or greater » Repair the open/high resistance in the circuit.
        • If less than 2 Ω » Replace the component: KR191L Pickup Box Endgate Latch Relay - Left or KR191R Pickup Box Endgate Latch Relay - Right
    • If the specified state
  14. Test or replace the component: A99C Pickup Box Endgate Latch - Center
Test 3

Note: It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems » Off
  2. Disconnect the electrical connector: S86 Vehicle Stability Control Switch
  3. Test for less than 10 Ω between the test points: Ground circuit terminal 6 & Ground
    • If 10 Ω or greater
    1. Ground Connection » Disconnect
    2. Test for less than 2 Ω between the test points: Ground circuit terminal 6 @ Component harness & Ground Connection
      • If 2 Ω or greater » Repair the open/high resistance in the circuit.
      • If less than 2 Ω » Repair the open/high resistance in the ground connection.
    • If less than 10 Ω
  4. Ignition » On / Vehicle » In Service Mode
  5. Momentarily connect a 3 A fused jumper wire between the test points: Signal circuit terminal 3 & Ground circuit terminal 6

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: A99C Pickup Box Endgate Latch - Center

    • If the component does not turn On and Off
    1. Ignition/Vehicle » Off & Remove » Jumper wire(s)
    2. Disconnect the electrical connector: K9 Body Control Module
    3. Ignition » On / Vehicle » In Service Mode
    4. Test for less than 1 V between the test points: Signal circuit terminal 3 @ Component harness & Ground
      • If 1 V or greater » Repair the short to voltage on the circuit.
      • If less than 1 V
    5. Ignition/Vehicle » Off
    6. Test for infinite resistance between the test points: Signal circuit terminal 3 @ Component harness & Ground
      • If less than infinite resistance » Repair the short to ground on the circuit.
      • If infinite resistance
    7. Test for less than 2 Ω between the test points: Signal circuit terminal 3 @ Component harness & Terminal 5 X6 @ Control module harness
      • If 2 Ω or greater » Repair the open/high resistance in the circuit.
      • If less than 2 Ω » Replace the component: K9 Body Control Module
    • If the component turns On and Off
  6. Test or replace the component: S86 Vehicle Stability Control Switch
Component Testing
A99C Pickup Box Endgate Latch - Center

Caution: Complete the testing as quickly as possible in order to prevent overheating and damaging the component.

  1. Ignition/Vehicle » Off
  2. Disconnect the electrical connector: A99C Pickup Box Endgate Latch - Center
  3. Connect a jumper wire between the test points: Control terminal 2 & Ground
  4. Momentarily connect a 10 A fused jumper wire between the test points: Control terminal 1 & 12 V

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: A99C Pickup Box Endgate Latch - Center

    • If the component does not turn On and Off

      Replace the component: A99C Pickup Box Endgate Latch - Center

    • If the component turns On and Off
  5. All OK.
S159E Pickup Box Endgate Control Switch - Exterior
  1. Ignition/Vehicle » Off
  2. Disconnect the electrical connector: S159E Pickup Box Endgate Control Switch - Exterior
  3. Test for infinite resistance between the test points: Signal terminal 1 & Ground terminal 2 » Not Pressed
    • If less than infinite resistance

      Replace the component: S159E Pickup Box Endgate Control Switch - Exterior

    • If infinite resistance
  4. Test for less than 3 Ω between the test points: Signal terminal 1 & Ground terminal 2 » Pressed
    • If 3 Ω or greater

      Replace the component: S159E Pickup Box Endgate Control Switch - Exterior

    • If less than 3 Ω
  5. All OK.
S86 Vehicle Stability Control Switch
  1. Ignition/Vehicle » Off
  2. Disconnect the electrical connector: S86 Vehicle Stability Control Switch
  3. Test for infinite resistance between the test points: Signal terminal 3 & Ground terminal 6 » Not Pressed
    • If less than infinite resistance

      Replace the component: S86 Vehicle Stability Control Switch

    • If infinite resistance
  4. Test for less than 3 Ω between the test points: Signal terminal 3 & Ground terminal 6 » Pressed
    • If 3 Ω or greater

      Replace the component: S86 Vehicle Stability Control Switch

    • If less than 3 Ω
  5. All OK.
Relay Test
  1. Ignition/Vehicle » Off
  2. Remove the appropriate component: KR191L Pickup Box Endgate Latch Relay - Left or KR191R Pickup Box Endgate Latch Relay - Right
  3. Test for 70 to 110 Ω between the test points: Component terminal 85 & 86
    • If not between 70 and 110 Ω

      Replace the component: KR191L Pickup Box Endgate Latch Relay - Left or KR191R Pickup Box Endgate Latch Relay - Right

    • If between 70 and 110 Ω
  4. Test for infinite resistance between the test points:
    • Component terminal 30 & 85
    • Component terminal 30 & 86
    • Component terminal 30 & 87
    • Component terminal 85 & 87
    • Component terminal 87A & 86
    • Component terminal 87A & 87
    • Component terminal 87A & 85
    • Component terminal 87A & 30
    • If less than infinite resistance

      Replace the component: KR191L Pickup Box Endgate Latch Relay - Left or KR191R Pickup Box Endgate Latch Relay - Right

    • If infinite resistance
  5. Test for less than 2 Ω between the test points: Component terminal 30 & 87A
    • If 2 Ω or greater

      Replace the component: KR191L Pickup Box Endgate Latch Relay - Left or KR191R Pickup Box Endgate Latch Relay - Right

    • If less than 2 Ω
  6. Connect a 3 A fused jumper wire between the test points: Component terminal 86 & 12 V

    Connect a jumper wire between the test points: Component terminal 85 & Ground

  7. Test for less than 2 Ω between the test points: Component terminal 30 & 87
    • If 2 Ω or greater

      Replace the component: KR191L Pickup Box Endgate Latch Relay - Left or KR191R Pickup Box Endgate Latch Relay - Right

    • If less than 2 Ω
  8. All OK.
Edited by newdude

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,759
    Total Members
    8,960
    Most Online
    DM22
    Newest Member
    DM22
    Joined
  • Who's Online   3 Members, 0 Anonymous, 1,615 Guests (See full list)

  • Latest Articles

  • Posts

    • Did have to make 1 modification because of the WeatherTech rear mud flaps and that was needing 3 longer screws than what came with the install package. 😄
    • Picked up the liners yesterday. Installed passenger side WITHOUT any modifications. All mounting holes lined up perfectly. Rain is interfering today with drivers side. Very Happy! Will add pics when finished
    • As a matter of amusement I’ll leave this conversation with this. Do you beat the government average fuel estimate? Statistics are a guide to me. Not a rule. Someone once said I have to have the last word. If true and possible may be. I’ll blame that on working in a family business.
    • That is a fair point, and I agree that trying to log “everything in the truck” would be the wrong direction.   There are a lot of modules and a lot of traffic. If the product became a full-truck datalogger, the amount of data would get huge very quickly, and most owners would never use it.   I think the first useful version would need to be narrow: - powertrain-side event evidence - selected high-value parameters - communication / voltage / reset events - pre/post event window - short report first, raw log only as backup   One distinction I should make is between active OBD/PID polling and passive bus capture. If you are polling PIDs through OBD, then yes: the more parameters you request, the lower the effective sample rate becomes, and you are adding diagnostic traffic to a vehicle that is already busy running itself. With passive CAN capture, the recorder is not asking all the modules for data. It is listening to traffic that is already on the bus. So it does not consume vehicle bus bandwidth in the same way that a scan tool polling hundreds of PIDs would. But your point still applies in a different way.   Even if passive capture does not add bus traffic, the recorder still has limits: - processing rate - storage rate - timestamp accuracy - decoder workload - event filtering - report size - user attention span   So the answer cannot be “log everything and let the user figure it out.” The product would need to store enough raw evidence to be useful, but only decode, graph, and present the important parts around the event.   A practical report should probably show: - what triggered the capture - how much pre/post data was preserved - which selected parameters changed - how those values compared to baseline - whether the same pattern happened before - whether any voltage, reset, bus-off, lost-message, or communication fault occurred - selected graphs around the event - raw data only as supporting evidence   So I agree with you. More data is not automatically better. The real product is the reduction from raw data into a useful event report.
    • That makes sense, and I agree with most of that.   I think the product would need both: 1. a default powertrain template, so it is useful out of the box; 2. user-selected priority parameters, so the owner or shop can choose what they want to see first.   Different users are going to care about different things. One owner may care about oil pressure and voltage. Another may care about misfire trend, AFM/DFM behavior, or U-codes. A shop may want communication events and repeatability first. Your baseline point is probably the most important one. Raw data is not very useful unless the report can show what normal looked like for that vehicle under similar conditions.   The way I would think about it is: - start with a basic known-good baseline - learn normal behavior for that specific vehicle over time - allow the event to be overlaid against baseline - show whether the event was a one-time spike or a repeatable pattern - provide a simple severity level, but with clear limits on what that severity means   For example, early severity could be something like: - Info: event captured, no obvious abnormal pattern - Watch: value moved outside baseline, but not repeated - Warning: repeatable abnormal pattern under similar conditions - Critical: communication loss, voltage drop, bus-off, reset, or severe repeated event   I would not want the first version to say “replace this part.” That would be overclaiming unless there is repair-confirmed data behind it. It would be more honest to say “this pattern deserves inspection.”   On the OBD port question, I think OBD absolutely has a role. OBD is probably the right place for: - DTCs - freeze frame - VIN - calibration information - normal scan-tool parameters - Mode 6 / enhanced diagnostic data if available The reason I am still looking at an ECM-side recorder is that the failure may happen before anyone connects a scan tool. If the owner plugs in a scanner after the event, the pre-event evidence may already be gone unless the ECU happened to save it. So I do not see this as “OBD versus ECM-side.” I see it more like: - ECM-side recorder: always armed, rolling buffer, event evidence - OBD/DLC companion: DTCs, freeze frame, VIN, calibration, normal scan data - phone/cloud: status, notes, upload, report generation, notifications   I agree that phone connection and push notifications would be useful. I just would not want the phone or cloud connection to be required for capture. The recorder should save the event locally even if the phone is not connected. The phone should help with event marking, download, notes, upload, alerts, and report viewing.   For a default GM V8 event report, would this list make sense? - RPM - calculated load / MAP - throttle position - vehicle speed - gear / torque converter state if available - coolant temperature - oil pressure - oil temperature if available - battery voltage - commanded AFM/DFM state if available - actual AFM/DFM state if available - misfire counters / roughness by cylinder if available - fuel trims - relevant U-codes / communication events - bus-off / lost periodic message / module reset / voltage drop events Which of those would you remove, and what would you add?
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...