[Val]

Anyone know what code P146E is for? 2021 Chevy Trailblazer (no warranty so I can’t take it to the dealer)

 

[keylightguy]

Diagnostic Instructions

• Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis
• An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions

DTC Descriptor
DTC P146D
EVAP Purge System Pressure Sensor Circuit Low Voltage
DTC P146E
EVAP Purge System Pressure Sensor Circuit High Voltage
DTC P146F
EVAP Purge System Pressure Sensor Performance
Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5 V Reference	P0641*	P146D	P0641*	P146F
Signal	P146D	P146D	P146E	P146F
Low Reference	—	P146E	—	P146F
* Additional DTCs may set.

Typical Scan Tool Data
EVAP Purge Pump Pressure Sensor

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition = On & Engine = Off Parameter Normal Range: 1.1 to 1.4 V
5 V Reference	0.0 V	0.0 V	4.2–5.0 V
Signal	0.0 V	0.0 V	5.0 V
Low Reference	—	4.9 V	—

Fuel Tank Pressure Sensor

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition = On & Engine = Off Parameter Normal Range: 1.3 to 1.7 V
5 V Reference	0.0 V	0.0 V	4.2 to 5.0 V
Signal	0.0 V	0.0 V	5.0 V
Low Reference	—	4.96 V	—

Circuit/System Description
For an overview of the component/system, refer to: Evaporative Emission Control System Description

Circuit	Description
5 V Reference	Regulated voltage supplied by the control module.
Signal	The control module input circuit has an internal resistance connected to ground.
Low Reference	Grounded through the control module.

Component	Description
EVAP Purge Pump Pressure Sensor	The pressure sensor is a 3 wire piezo-resistive pressure transducer. The sensor measures the pressure in the component: EVAP Purge Pump The sensor is integrated within the component: G58 Evaporative Emission Purge Pump
K20 Engine Control Module	The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.

Conditions for Running the DTC
P146D, P146E
Ignition = On or Engine = Idling

Frequency the DTC runs = Continuously — After the running conditions are met

• P146F
• DTCs related to the following system/component = Not Set
  • B34 Engine Coolant Temperature Sensor
  • B66 Intake Air Temperature Sensor
  • B75B Mass Air Flow/Intake Air Temperature Sensor
  • G58 Evaporative Emission Purge Pump
  • EVAP Purge Pump Pressure Sensor
  • Engine Control Module LIN Bus 2
  • Ignition Off Time
  • Network Configuration List Not Programmed - Engine Control Module LIN Bus 2
• Barometric Pressure Sensor = Greater than 70 kPa (10.0 PSI)
• Engine Off Time = Greater than 1 h
• M64 Starter Motor = Not cranking
• Start-Up Engine Coolant Temperature Sensor = Less than 35°C (95°F)
• Start-Up Engine Coolant Temperature Sensor & Start-Up Intake Air Temperature Sensor = Within 8°C (14°F) of each other
• Start-Up Intake Air Temperature Sensor = 4 to 35°C (39 to 95°F)

Frequency the DTC runs = Once — Per cold start-up — After the running conditions are met
Conditions for Setting the DTC
P146D
EVAP Purge Pump Pressure Sensor = Less than 0.2 V — For greater than 1 s
P146E
EVAP Purge Pump Pressure Sensor = Greater than 4.8 V — For greater than 1 s
P146F
EVAP Purge Pump Pressure Sensor = Not within a calibrated range — Unable to re-zero the voltage
Actions Taken When the DTC Sets
DTC P146D, P146E = Type B DTC

DTC P146F = Type A DTC
Conditions for Clearing the DTC
DTC P146D, P146E = Type B DTC

DTC P146F = Type A DTC
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference

Master Electrical Component List
Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References
Circuit/System Verification
Warning: Refer to: Fuel and Evaporative Emission Pipe Warning
Caution: Refer to: Clean, Dry, Low Pressure Gas Source Caution

1. Ignition » On / Vehicle » In Service Mode
2. Verify DTC P0641 is not set.
   • If the DTC is set
     Refer to: DTC P0641, P0651, P0697, or P06A3
3. • If the DTC is not set
4. Verify the following scan tool parameters are within the specified range:
   • EVAP Purge Pump Pressure Sensor = 1.1 to 1.4 V
   • Fuel Tank Pressure Sensor = 1.3 to 1.7 V
   • If both scan tool parameters are not within the specified range
5. 1. Ignition/Vehicle » Off
   2. Verify the condition does not exist with the component and repair as necessary:
      1. Evaporative Emission Vent Filter or Evaporative Emission Canister Air Inlet Hose — Blocked / Dirty / Ice / Restricted / Visible Damage
      2. Evaporative Emission Canister — Blocked / Ice / Restricted / Visible Damage
      3. Evaporative Emission Canister Vent Hose or Pipe — Blocked / Kinked / Restricted / Visible Damage
      4. Q13 Evaporative Emission Vent Solenoid Valve — Blocked / Mechanically stuck / Restricted / Visible Damage
      5. Evaporative Emission Canister Purge Hose — Blocked / Kinked / Restricted / Visible Damage
6. • If only the following scan tool parameter is not within the specified range: EVAP Purge Pump Pressure Sensor
     Refer to: Circuit/System Testing
7. • If both scan tool parameters are within the specified range
8. Verify the scan tool parameter: EVAP Purge Pump Pressure Sensor = The parameter value should not change
   Perform the action while monitoring the parameter:
   • Wiggle the harness and connector: G58 Evaporative Emission Purge Pump
   • Wiggle the harness and connector: K20 Engine Control Module
   • If the parameter value changes
     Repair as necessary » Wiring / Terminal(s) / Electrical Connector(s)
9. • If the parameter value does not change
10. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
    Verify the DTC does not set.
    • If the DTC sets
      Repeat the procedure starting at step 2
11. • If the DTC does not set
12. All OK.

Circuit/System Testing

1. Ignition/Vehicle » Off
2. Disconnect the component: Evaporative Emission Pipe — Canister - Side @ G58 Evaporative Emission Purge Pump
3. Ignition » On / Vehicle » In Service Mode
4. Verify the scan tool parameter: EVAP Purge Pump Pressure Sensor = 1.1 to 1.4 V
   • If between 1.1 and 1.4 V
     Repair the restriction between the following components: G58 Evaporative Emission Purge Pump & B150 Fuel Tank Pressure Sensor
5. • If not between 1.1 and 1.4 V
6. 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.
7. Ignition/Vehicle & All vehicle systems » Off
8. Disconnect the electrical connector: G58 Evaporative Emission Purge Pump
9. Test for less than 10 Ω between the test points: Low Reference circuit terminal 2 & Ground
   • If 10 Ω or greater
10. 1. Disconnect the appropriate electrical connector: K20 Engine Control Module
    2. Test for less than 2 Ω between the test points: Low Reference circuit terminal 2 @ Component harness & The other end of the circuit @ Control module harness
       • If 2 Ω or greater » Repair the open/high resistance in the circuit.
       • If less than 2 Ω » Replace the component: K20 Engine Control Module
11. • If less than 10 Ω
12. Ignition » On / Vehicle » In Service Mode
13. Test for 4.8 to 5.2 V between the test points: 5 V Reference circuit terminal 3 & Low Reference circuit terminal 2
    • If less than 4.8 V
14. 1. Ignition/Vehicle » Off
    2. Disconnect the appropriate electrical connector: K20 Engine Control Module
    3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 3 @ Component harness & Ground
       • If less than infinite resistance » Repair the short to ground on the circuit.
    4. • If infinite resistance
    5. Test for less than 2 Ω between the test points: 5 V Reference circuit terminal 3 @ Component harness & The other end of the circuit @ Control module harness
       • If 2 Ω or greater » Repair the open/high resistance in the circuit.
       • If less than 2 Ω » Replace the component: K20 Engine Control Module
15. • If greater than 5.2 V
16. 1. Ignition/Vehicle » Off
    2. Disconnect the appropriate electrical connector: K20 Engine Control Module
    3. Ignition » On / Vehicle » In Service Mode
    4. Test for less than 1 V between the test points: 5 V Reference circuit terminal 3 @ Component harness & Ground
       • If 1 V or greater » Repair the short to voltage on the circuit.
       • If less than 1 V » Replace the component: K20 Engine Control Module
17. • If between 4.8 and 5.2 V
18. Verify the scan tool parameter: EVAP Purge Pump Pressure Sensor = Less than 0.2 V
    • If 0.2 V or greater
19. 1. Ignition/Vehicle » Off
    2. Disconnect the appropriate electrical connector: K20 Engine 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 » Replace the component: K20 Engine Control Module
20. • If less than 0.2 V
21. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 1 & 5 V Reference circuit terminal 3
22. Verify the scan tool parameter: EVAP Purge Pump Pressure Sensor = Greater than 4.7 V
    • If 4.7 V or less
23. 1. Ignition/Vehicle » Off & Remove » Jumper wire(s)
    2. Disconnect the appropriate electrical connector: K20 Engine Control Module
    3. 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.
    4. • If infinite resistance
    5. Test for less than 2 Ω between the test points: Signal circuit terminal 1 @ Component harness & The other end of the circuit @ Control module harness
       • If 2 Ω or greater » Repair the open/high resistance in the circuit.
       • If less than 2 Ω » Replace the component: K20 Engine Control Module
24. • If greater than 4.7 V
25. Test or replace the component: G58 Evaporative Emission Purge Pump

Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification

• Evaporative Emission Canister Purge Pump Replacement — G58 Evaporative Emission Purge Pump
• For control module replacement, programming, and setup refer to: Control Module References

 

[psnyder53]

Excellent material. My head just exploded. 🤪 I have no questions.

 

[keylightguy]

Excellent material. My head just exploded. 🤪 I have no questions.

I believe there are other threads on this forum regarding the canister purge pump failing.

 

[brownactive]

This seems to be a common issue with these TB's. Warranty or not this is not overed as it is a emmisions issue?