Engine Control System - 4.8L, 5.3L, & 6.0L (Troubleshooting): Diagnosis Chevrolet SSR I

Important Preliminary Inspections Before Beginning

Before using this section, perform the Diagnostic System Check - Engine Controls and verify all of the following conditions

1. The powertrain control module (PCM) and the malfunction indicator lamp (MIL) are operating correctly. Refer to «Malfunction Indicator Lamp (MIL) Inoperative»(ref-187834-S08325188322005090100000) .
2. Diagnostic trouble codes (DTCs) are not stored.
3. The scan tool data is within the normal operating range. Refer to «Scan Tool Data List»(ref-187795-S37548384192005090100000) .
4. Verify the customer concern and locate the correct symptom table. Inspect the items indicated in that symptom table.
5. Several of the symptom procedures ask for a careful visual/physical inspection. This step is extremely important, and can lead to correcting a condition without further inspections and can save valuable time.
6. If the intermittent condition exists as a start and then stall, inspect for any DTCs related to the theft deterrent system. Refer to «Diagnostic System Check - Theft Deterrent»(ref-187812-S41043472642005090100000) in Theft Deterrent.
7. Verify the proper installation of any of the following aftermarket accessories: Lights Cellular phone Remote starter system Aftermarket installed alarm
8. Use the following tables when diagnosing a symptom concern: «Poor Fuel Fill Quality»(ref-187834-S01554823072005090100000) «Hard Start»(ref-187834-S05440058412005090100000) «Surges/Chuggles»(ref-187834-S30277858862005090100000) «Lack of Power, Sluggishness, or Sponginess»(ref-187834-S00045620032005090100000) «Detonation/Spark Knock»(ref-187834-S10176222112005090100000) «Hesitation, Sag, Stumble»(ref-187834-S01867412202005090100000) «Cuts Out, Misses»(ref-187834-S40596843552005090100000) «Poor Fuel Economy»(ref-187834-S06408734432005090100000) «Rough, Unstable, or Incorrect Idle and Stalling»(ref-187834-S28270832532005090100000) «Dieseling, Run-On»(ref-187834-S00719466572005090100000) «Backfire»(ref-187834-S17373217922005090100000)
9. If the condition cannot be isolated using the appropriate table, refer to «Intermittent Conditions»(ref-187834-S14533598112005090100000) for further diagnosis.

Circuit Description

Ignition voltage is supplied to the malfunction indicator lamp (MIL). The powertrain control module (PCM) turns the MIL ON by grounding the MIL control circuit. There should be a steady MIL with the ignition ON and the engine OFF.

Ignition voltage is supplied to the malfunction indicator lamp (MIL). The powertrain control module (PCM) turns the MIL ON by grounding the MIL control circuit.

Diagnostic Aids

If the problem is intermittent, refer to Intermittent Conditions .

The ignition relay is a normally open relay. The relay armature is held in the open position by spring tension. When the ignition switch is turned to the run or start position, current will flow through the relay coil. A wire connected to the other end of the relay coil completes the path to ground. The electromagnetic field created by the relay coil overcomes the spring tension and pulls the armature contact into the stationary contact of the relay load circuit. The closed relay contacts allows current to flow from the battery to the following fuses

1. ETC
2. INJ A
3. INJ B

When the ignition switch is turned to the OFF position, the electromagnetic field collapses. This action allows the spring tension to move the armature contact away from the relay load circuit contacts, which interrupts current flow to the fuses.

If the ignition relay fails to close, the engine will crank, but will not run. The class 2 communications will be available with the use of a scan tool.

The ignition relay table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test (Non-HP2) in Engine Electrical.

Ignition Relay Diagnosis

The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within two seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within two seconds if ignition reference pulses cease to be detected and the ignition remains ON.

A fuel pump prime terminal is located at the underhood bussed electrical center (UBEC). Refer to the UBEC cover for terminal location.

The following conditions may have caused the fuel pump fuse to open

1. A faulty fuse
2. An intermittent short in the fuel pump power supply circuit
3. An intermittent internal component failure

For an intermittent condition, refer to Intermittent Conditions .

The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied directly to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver. A fuel injector coil winding resistance that is too high or too low will affect engine driveability. A fuel injector control circuit DTC may not set, but a misfire may be apparent. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

1. The use of Dielectric compound GM P/N 12377900 (Canadian P/N 10953529) in the fuel injector electrical connector may eliminate a corrosion condition.
2. Monitoring the misfire current counters, or misfire graph, may help isolate the fuel injector that is causing the condition.
3. Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
4. Perform the fuel injector coil test within the conditions of the customers concern. A fuel injector condition may only be apparent at a certain temperature, or under certain conditions.
5. If the fuel injector coil test does not isolate the condition perform the fuel injector balance test. Refer to «Fuel Injector Balance Test with Special Tool»(ref-187834-S28634177642005090100000) or «Fuel Injector Balance Test with Tech 2»(ref-187834-S02492992862005090100000) .

Fuel Injector Coil Test

1. Operate the vehicle under the condition of the customers concern. Under high temperature conditions fuel vapors may increase to the point of EVAP canister vapor saturation. Fuel vapors would then be released into the atmosphere. Once the engine is running and EVAP purge is enabled, all fuel vapor release would be eliminated.
2. Movement of the EVAP pipes or fuel pipes may help find an intermittent condition.
3. If the fuel level is low, a leak may not be evident.

Alcohol in Fuel Testing Procedure

The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The sample should be bright and clear. If alcohol contamination is suspected then use the following procedure to test the fuel quality.

1. Using a 100 ml specified cylinder with 1 ml graduation marks, fill the cylinder with fuel to the 90 ml mark.
2. Add 10 ml of water in order to bring the total fluid volume to 100 ml and install a stopper.
3. Shake the cylinder vigorously for 10-15 seconds.
4. Carefully loosen the stopper in order to release the pressure.
5. Re-install the stopper and shake the cylinder vigorously again for 10-15 seconds.
6. Put the cylinder on a level surface for approximately 5 minutes in order to allow adequate liquid separation.

If alcohol is present in the fuel, the volume of the lower layer, which would now contain both alcohol and water, will be more than 10 ml. For example, if the volume of the lower layer is increased to 15 ml, this indicates at least 5 percent alcohol in the fuel. The actual amount of alcohol may be somewhat more because this procedure does not extract all of the alcohol from the fuel.

Particulate Contaminants in Fuel Testing Procedure

The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The sample should be bright and clear. If the sample appears cloudy, or contaminated with water, as indicated by a water layer at the bottom of the sample, use the following procedure to diagnose the fuel.

1. Using an approved fuel container, draw approximately 0.5 liter of fuel.
2. Place the cylinder on a level surface for approximately 5 minutes in order to allow settling of the particulate contamination.

Particulate contamination will show up in various shapes and colors. Sand will typically be identified by a white or light brown crystals. Rubber will appear as black and irregular particles. If particles are found clean the entire fuel system thoroughly. Refer to Fuel System Cleaning .

Test Procedure

1. Test the fuel composition using J 44175 Fuel Composition Tester and J 44175-3 Instruction Manual.
2. If water appears in the fuel sample, perform the following steps: Clean the fuel system. Refer to «Fuel System Cleaning»(ref-187797-S18219204092005090100000) . Replace the fuel filter if the vehicle is equipped with a serviceable fuel filter.
3. Subtract 50 from the reading on the DMM in order to obtain the percentage of alcohol in the fuel sample. Refer to the examples in the Fuel Composition Test Examples table.
4. If the non-blended gasoline fuel sample contains more than 15 percent ethanol, or if the E85 blended gasoline fuel sample contains more than 85 percent ethanol, add fresh, regular gasoline to the vehicle's fuel tank.
5. Test the fuel composition.
6. If additional testing indicates that the ethanol percentage is still more above 15 percent for a non-blended gasoline sample, drain and replace the vehicle's fuel. Refer to «Fuel System Cleaning»(ref-187797-S18219204092005090100000) . If additional testing indicates that the E85 blended gasoline sample is still above 85 percent, continue adding fresh, regular gasoline until the ethanol content is 85 percent or less.

Fuel Composition Test Examples

The electronic ignition system uses an individual ignition coil for each cylinder. The powertrain control module (PCM) controls the ignition operation through eight individual ignition control (IC) circuits. Each bank of four ignition coils is connected to the PCM, power, or ground by the following circuits

1. Low reference
2. Chassis ground
3. Ignition 1 voltage
4. The appropriate IC circuit

The PCM triggers an ignition coil by grounding the appropriate IC circuit using information from the crankshaft position (CKP) and camshaft position (CMP) sensors.

For an intermittent condition, refer to Intermittent Conditions .

Conditions for Running

Cold Start

1. The barometric pressure (BARO) is more than 75 kPa.
2. The engine coolant temperature (ECT) is between 4-30° C (39-86° F).
3. The intake air temperature (IAT) is between 4-30° C (39-86° F).
4. The difference between the IAT and the ECT is 8° C (14° F) or less.
5. The battery voltage is between 10-18 volts.
6. The fuel level is between 15-85 percent.

Rough road conditions may prevent some of the tests from running. Extreme high or low ambient temperatures may prevent tests such as for the heated oxygen sensor (HO2S) heater and the evaporative emission (EVAP) system from initiating. If a step is interrupted before completion, perform the remaining portion of the set procedures. Any portion of the set procedure that requires the engine at operating temperature may be repeated. This allows most of the diagnostics to run and the remaining tests can be performed using the individual System Set Procedures.

The scan tool can be used in order to monitor each of the I/M System Status indicators during the I/M Complete System Set Procedure. When all of the indicators for a test step have updated to YES, testing can move on to the next step even if the remaining portion of the test is not complete. For example, step 3 is designed to run the EVAP, AIR, and HO2S tests. The procedure instructs the technician to operate the vehicle in the enable conditions for 6 minutes. If all 3 tests have updated to YES within 4 minutes, you do not need to continue with the enable conditions and testing can advance to the next step.

Inspection/Maintenance (I/M) System DTC Table

Inspection/Maintenance (I/M) System DTC Table

1. The engine load must be stable.
2. DTCs P0420 and P0430 are not set.
3. The barometric pressure is more than 74 kPa.
4. The engine coolant temperature (ECT) is between 70-120° C (158-248° F).
5. The engine has been running for more than 10 minutes.
6. The engine is in Closed Loop fuel control.
7. The battery voltage is more than 10-18 volts.
8. The intake air temperature (IAT) is between -7 and +85° C (+20 and +185° F).
9. The difference between the engine speed and the desired engine speed is less than 200 RPM.

The control module runs a calibrated number of catalyst tests per trip until the Catalyst System Status updates to YES. If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES.

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load such as a cooling fan or A/C compressor clutch turning ON may cause the test to abort.

Inspection/Maintenance (I/M) Catalyst System Set Procedure (Without HP2)

1. DTCs P0442, P0446, P0455, P0496 are not set.
2. The barometric pressure (BARO) is more than 75 kPa.
3. The fuel level is between 1/4 and 3/4.
4. The battery voltage is between 10-18 volts.
5. The engine coolant temperature (ECT) is between 3.75-30° C (39-86° F).
6. The intake air temperature (IAT) is between 3.75-30° C (39-86° F).
7. The difference between the ECT and the IAT is less than 8° C (14° F).

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load such as cooling fan or an A/C compressor clutch turning ON may cause the test to abort.

Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure

1. DTCs P0133, P0135, P0136, P0140, P0141, P0153, P0155, P0156, P0160, P0161, P1133, P1134, P1153, P1154 are not set.
2. The fuel level is more than 10 percent.
3. The engine coolant temperature (ECT) is more than 60° C (140° F).
4. The engine is running in Closed Loop fuel control.
5. The engine has been running for more than 3 minutes.
6. The battery voltage is between 10-18 volts.
7. The mass air flow (MAF) is between 20-55 grams per second.
8. The engine speed is between 1,200-3,000 RPM.
9. The throttle position (TP) sensor is more than 5 percent.

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load such as a cooling fan or A/C compressor clutch turning ON may cause the test to abort.

Inspection/Maintenance (I/M) Heated Oxygen Sensor/Oxygen Sensor (HO2S/O2S) System Set Procedure

1. DTCs P0135, P0141, P0155, P0161 are not set.
2. The engine has been running for more than 2 minutes.
3. The engine coolant temperature (ECT) is more than 50° C (122° F).
4. The engine speed is between 500-3,000 RPM.
5. The battery voltage is between 10-18 volts.
6. The mass air flow (MAF) is between 3-40 grams per second.

The HO2S Heater Tests will normally run within the 2 minutes allotted in the procedure. If there is an indeterminate condition, the test may take up to 8 minutes on some vehicles before a decision of pass or fail is made. If the test does not update to YES, it may have failed or aborted due to the loss of enabling conditions. Extremely high ambient temperatures may prevent the HO2S Heater Test from initiating.

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load such as a cooling fan or A/C compressor clutch turning ON may cause the test to abort.

Inspection/Maintenance (I/M) Heated Oxygen Sensor (HO2S) Heater System Set Procedure