Auxiliary Water Pump Terminal Identification - HP2
Auxiliary Water Pump Terminal Identification - HP2 Connector Part Information 12084126 2-Way F Sealed (BLK) Pin Wire Color Circuit No. Function A BLK 550 Ground B TAN/WHT 5543 Auxiliary Heater Pump Voltage
Coolant Level Switch Terminal Identification - 8.1L
Coolant Level Switch Terminal Identification - 8.1L Connector Part Information 12052644 2-Way F Metri-Pack 150 Series Sealed (GRY) Pin Wire Color Circuit No. Function A LT GRN 1478 Coolant Level Switch Signal B BLK 550 Ground
Coolant Level Switch Terminal Identification - Diesel
Coolant Level Switch Terminal Identification - Diesel Connector Part Information 15324243 2-Way F Metri-Pack 150 Series Sealed (GRY) Pin Wire Color Circuit No. Function A LT GRN 1478 Coolant Level Switch Signal B BLK 550 Ground
Starter/Generator Control Module Coolant Pump Terminal Identification - HP2
Starter/Generator Control Module Coolant Pump Terminal Identification - HP2 Connector Part Information 12131678 2-Way F Sealed (BLK) Pin Wire Color Circuit No. Function A BLK 150 Ground B LT BLU 703 Ignition 1 Voltage
Starter/Generator Control Module Fan Terminal Identification - HP2
Starter/Generator Control Module Fan Terminal Identification - HP2 Connector Part Information 15326801 2-Way F GT 150 Series Sealed (BLK) Pin Wire Color Circuit No. Function A LT BLU 409 Cooling Fan Motor Supply Voltage B BLK 150 Ground
Scheme 8
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 3: Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
- 4: Determine if the Instrument Cluster or Powertrain Control Modules have set DTCs which may affect Engine Cooling operation are present.
- 5: The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you review a Diagnostic Starting Point-Engine Cooling? | Go to Step 2 | Go to Diagnostic Starting Point - Engine Cooling |
| 2 | Install a scan tool. Does the scan tool power up? | Go to Step 3 | Go to Scan Tool Does Not Power Up in Data Link Communications |
| 3 | Turn ON the ignition, with the engine OFF. Attempt to establish communication with the following control modules: The instrument cluster The powertrain control module Does the scan tool communicate with the control modules? | Go to Step 4 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications |
| 4 | Select the powertrain control module display DTCs function on the scan tool. Does the scan tool display any DTCs? | Go to Step 5 | Go to Symptoms - Engine Cooling |
| 5 | Does the scan tool display any DTCs which begin with a "U"? | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | Go to Step 6 |
| 6 | Does the scan tool display any DTCs that are associated with the Engine Cooling System? | Go to Diagnostic Trouble Code (DTC) List | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 4.8L, 5.3L, and 6.0L or Diagnostic Trouble Code (DTC) List in Engine Controls - 8.1L |
Diagnostic System Check - Engine Cooling
The number below refers to the step number on the diagnostic table.
- 2: Verifies that the condition that set the DTC is present.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views | ||||
| 1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Engine Cooling | |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. Select the HCM display DTC function on the scan tool. Does the scan tool indicate that B0159 is a current DTC? | Go to Step 3 | Go to Diagnostic Aids | |
| 3 | Turn OFF the ignition. Disconnect the ambient air temperature sensor. Turn ON the ignition, with the engine OFF. Measure the voltage from the signal circuit of the ambient air temperature sensor to a good ground. Does the voltage measure near the specified value? | 5 V | Go to Step 4 | Go to Step 5 |
| 4 | Measure the voltage from the signal circuit to the low reference circuit of the ambient air temperature sensor. Does the voltage measure near the specified value? | 5 V | Go to Step 7 | Go to Step 6 |
| 5 | Test the signal circuit of the ambient air temperature sensor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 8 | |
| 6 | Test the low reference circuit of the ambient air temperature sensor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 8 | |
| 7 | Inspect for poor connections at the harness connector of the ambient air temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 9 | |
| 8 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 10 | |
| 9 | Replace the ambient air temperature sensor. Refer to Ambient Air Temperature Sensor Replacement in HVAC Systems - Automatic. Did you complete the replacement? | Go to Step 11 | ||
| 10 | Replace the HVAC control module. Refer to HVAC Control Module Replacement in HVAC Systems - Automatic. Did you complete the replacement? | Go to Step 11 | ||
| 11 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset? | Go to Step 2 | System OK | |
DTC B0159
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the auxiliary water pump relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- 3: Tests for voltage at the coil side of the auxiliary water pump relay. The AUX HTR PUMP fuse supplies power to the coil side of the auxiliary water pump relay.
- 4: Verifies that the HCM is providing ground to the auxiliary water pump relay.
- 5: Tests if ground is constantly being applied to the auxiliary water pump relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views | |||
| 1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Engine Cooling |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the Auxiliary Coolant Pump Relay ON and OFF. Does the auxiliary water pump relay turn ON and OFF with each command? | Go to Diagnostic Aids | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the auxiliary water pump relay. Turn ON the ignition, with the engine OFF. Probe the battery positive voltage circuit of the auxiliary water pump relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 10 |
| 4 | Connect a test lamp between the control circuit of the auxiliary water pump relay and the battery positive voltage circuit of the auxiliary water pump relay. With a scan tool, command the Auxiliary Coolant Pump Relay ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 5 |
| 5 | Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 |
| 6 | Test the control circuit of the auxiliary water pump relay for a short to voltage and an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 7 | Test the control circuit of the auxiliary water pump relay for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 8 | Inspect for poor connections at the auxiliary water pump relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 11 |
| 9 | Inspect for poor connections at the harness connector of the HCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Repair the battery positive voltage circuit of the auxiliary water pump relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the auxiliary water pump relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement? | Go to Step 13 | |
| 12 | IMPORTANT: Perform the set up procedure for the HCM. Replace the HCM. Refer to Hybrid Control Module (HCM) Replacement (5.3L Engine w/RPO HP2) in Engine Electrical.Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset? | Go to Step 2 | System OK |
| IMPORTANT |
|---|
| Perform the set up procedure for the HCM. |
DTC B3844
The numbers below refer to the step numbers on the diagnostic table.
- 2: During the SGCM coolant pump relay operation, listen for an audible click. Command the ON and the OFF states. Repeat the commands as necessary.
- 3: Verifies that the SGCM is providing voltage to the SGCM coolant pump relay.
- 4: Tests for an open in the ground circuit to the SGCM coolant pump relay.
- 5: Tests for constant voltage to the SGCM coolant pump relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views | |||
| 1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Engine Cooling |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the SGCM Pump Speed ON and OFF. Does the SGCM coolant pump relay turn ON and OFF with each command? | Go to Diagnostic Aids | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the starter/generator control module (SGCM) coolant pump relay. Turn ON the ignition, with the engine OFF. Connect a test lamp to ground. Probe the control circuit of the SGCM coolant pump relay with a test lamp that is connected to battery positive voltage. With a scan tool, command the SGCM Pump Speed ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 4 | Go to Step 5 |
| 4 | Connect a test lamp between the control circuit of the SGCM coolant pump relay and the ground circuit of the SGCM coolant pump relay. With a scan tool, command the SGCM Pump Speed ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 10 |
| 5 | Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 |
| 6 | Test the control circuit of the SGCM coolant pump relay for a short to ground and an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 7 | Test the control circuit of the SGCM coolant pump relay for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 8 | Inspect for poor connections at the SGCM coolant pump relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 11 |
| 9 | Inspect for poor connections at the harness connector of the SGCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Repair the ground circuit of the SGCM coolant pump relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | |
| 11 | IMPORTANT: Perform the programming procedure for the SGCM. Replace the SGCM coolant pump relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems.Did you complete the replacement? | Go to Step 13 | |
| 12 | IMPORTANT: Always perform the setup procedure for the SGCM. Replace the SGCM. Refer to Starter/Generator Control Module (SGCM) Replacement (5.3L Engine w/RPO HP2) in Engine Electrical.Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC. Does the DTC reset? | Go to Step 2 | System OK |
| IMPORTANT |
|---|
| Perform the programming procedure for the SGCM. |
| IMPORTANT |
|---|
| Always perform the setup procedure for the SGCM. |
DTC P0A06 or P0A07
The numbers below refer to the step numbers on the diagnostic table.
- 2: During the SGCM cooling fan relay operation, listen for an audible click. Command the ON and the OFF states. Repeat the commands as necessary.
- 3: Verifies that the SGCM is providing voltage to the SGCM cooling fan relay.
- 4: Tests for an open in the ground circuit to the SGCM cooling fan relay.
- 5: Tests for constant voltage to the SGCM cooling fan relay.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views | |||
| 1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Engine Cooling |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the SGCM Fan Speed ON and OFF. Does the SGCM cooling fan relay turn ON and OFF with each command? | Go to Diagnostic Aids | Go to Step 3 |
| 3 | Turn OFF the ignition. Disconnect the starter/generator control module (SGCM) cooling fan relay. Turn ON the ignition, with the engine OFF. Connect a test lamp to ground. Probe the control circuit of the SGCM cooling fan relay with a test lamp that is connected to battery positive voltage. With a scan tool, command the SGCM Fan Speed ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 4 | Go to Step 5 |
| 4 | Connect a test lamp between the control circuit of the SGCM cooling fan relay and the ground circuit of the SGCM cooling fan relay. With a scan tool, command the SGCM Fan Speed ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 10 |
| 5 | Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 |
| 6 | Test the control circuit of the SGCM cooling fan relay for a short to ground and an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 7 | Test the control circuit of the SGCM cooling fan relay for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
| 8 | Inspect for poor connections at the SGCM cooling fan relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 11 |
| 9 | Inspect for poor connections at the harness connector of the SGCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
| 10 | Repair the ground circuit of the SGCM cooling fan relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | |
| 11 | Replace the SGCM cooling fan relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) in Wiring Systems. Did you complete the replacement? | Go to Step 13 | |
| 12 | IMPORTANT: Perform the programming procedure for the SGCM. Replace the SGCM. Refer to Starter/Generator Control Module (SGCM) Replacement (5.3L Engine w/RPO HP2) in Engine Electrical.Did you complete the replacement? | Go to Step 13 | |
| 13 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC. Does the DTC reset? | Go to Step 2 | System OK |
| IMPORTANT |
|---|
| Perform the programming procedure for the SGCM. |
DTC P1AC1 or P1AC2
- 2: Be sure power supply cord is unplugged for 10 minutes prior to testing.
| Step | Action | Yes | No |
|---|---|---|---|
| Connector End View Reference: Cooling System Connector End Views | |||
| 1 | Did you perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Cooling |
| 2 | Test the engine coolant heater power supply cord for an open or short to ground. Refer to Circuit Testing in Wiring Systems. Did you find a condition? | Go to Step 3 | Go to Step 4 |
| 3 | Replace the engine coolant heater power supply cord. Refer to Coolant Heater Cord Replacement . Did you complete the repair? | Go to Step 6 | |
| 4 | Inspect for poor connections at the harness connector of the engine coolant heater. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 5 |
| 5 | Replace the engine coolant heater. Refer to Coolant Heater Replacement (4.3L) or Coolant Heater Replacement (4.8L, 5.3L, and 6.0L) or Coolant Heater Replacement (6.6L Engine) or Coolant Heater Replacement (8.1L) . Did you complete the repair? | Go to Step 6 | |
| 6 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
Coolant Heater Inoperative
Starter Generator Control Module Cooling System Description and Operation
The starter/generator control module (SGCM) cooling system description and operation is divided into three areas
- SGCM Cooling System Components
- SGCM Cooling System Operation
- SGCM Cooling System Coolant Cycle
SGCM Cooling System Operation
The purpose of the starter/generator control module (SGCM) coolant system is to cool the SGCM internal electronics. The SGCM commands the SGCM the SGCM coolant pump and coolant fan ON or OFF at the following temperatures
- Coolant pump from OFF to ON at 60° C (140° F)
- Coolant pump from ON to OFF at 55° C (131° F)
- Coolant fan from OFF to low speed at 75° C (167° F)
- Coolant fan from low speed to high speed at 80° C (176° F)
- Coolant fan from high speed to low speed at 75° C (167° F)
- Coolant fan from low speed to OFF at 70° C (158° F)