2016 - 2019 Cadillac CTS-V: Service Bulletin: #20-NA-200: Diagnostic Tip for Malfunction Indicator Lamp (MIL) Illuminated - DTC P0172 and/or P0175 Set

Cadillac

CTS-V

2016

2019

All

All

6.2L (LT4)

All

Escalade

2015

2019

All

All

6.2L (L86)

All

Chevrolet

Camaro

2016

2019

All

All

6.2L (LT1, LT4)

All

Corvette

2016

2019

All

All

6.2L (LT1, LT4, LT5)

All

Silverado

2014

2018

All

All

4.3L, 5.3L, 6.2L (L83, L8B, L86, LV1, LV3)

All

Silverado LD

2019

2019

Suburban

2015

2019

All

All

5.3L (L83)

All

Tahoe

2015

2019

All

All

5.3L (L83)

All

GMC

Sierra 1500

2014

2018

All

All

4.3L, 5.3L, 6.2L (L83, L86, L8B, LV1, LV3)

All

Sierra Limited

2019

2019

Yukon Models

2015

2019

All

All

5.3L, 6.2L (L83, L86)

All

Involved Region or Country

North America, Uzbekistan, Russia, Middle East, Israel, Palestine, Colombia, Ecuador, Paraguay, Japan, Singapore, Philippines, Other Africa

Condition

Some customers may comment that the MIL is illuminated.

Some technicians may find one or more of the following DTCs set in the Engine Control Module (ECM).

• - P0172: Fuel Trim System Rich Bank 1
• - P0175: Fuel Trim System Rich Bank 2

Cause

This condition may be caused by a possible high pressure fuel pump.

Correction

If SI does not isolate the cause of the rich condition, the following information may be helpful:

1. 1. Disconnect the dirty air side of the PCV system.
2. 2. Plug the vacuum supply.
3. 3. Start the engine and monitor the fuel trims in closed loop.

• - If the fuel trims return to normal, this is a good indicator that the high pressure fuel pump is leaking.

With this concern, we do not see a lot of fuel in the crankcase, so changing the oil may not isolate the concern. 

When the high pressure fuel pump leaks, the PCV will pull the fuel mist straight into the intake, causing the concern.  

Version

1

Modified

Released September 25, 2020