Circuit/System Verification
WARNING: This page is about a different car, the 2017 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
This diagnostic assumes the following:
- The battery is completely charged.
- The engine cranking speed is acceptable.
- There is adequate fuel in the fuel tank.
- Crank the engine for up to 15 seconds.
- Verify that DTC P0117, P0118, P0122, P0123, P0201 - P0208, P0222, P0223, P0300 - P0308, P0335, P0336, P0351 - P0358, P0562, P0563, P0601 - P0604, P0606, P0607, P062F, P0633, P0685, P0690, P1631, P1682, or P2610 is not set.
- If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If none of the DTCs are set
- If any of the DTCs are set
- Ignition ON
- Verify the security indicator on the instrument cluster illuminates momentarily.
- If the security indicator stays ON or is flashing
Review the Diagnostic Trouble Code (DTC) List - Vehicle , for Immobilizer system DTCs. For additional information, refer to Immobilizer Description and Operation .
- If the security indicator does not stay ON and is not flashing
- If the security indicator stays ON or is flashing
- Verify the scan tool Engine Speed parameter displays greater than 0 RPM while cranking the engine.
- If 0 RPM
Refer to DTC P0335 or P0336 .
- If greater than 0 RPM
- If 0 RPM
- Ignition OFF, disconnect a spark plug wire from one of the spark plugs.
- Connect the EL 26792 HEI Spark Tester between the spark plug boot and ground.
- Perform the spark test on at least one cylinder from each engine bank.
- An erratic or weak spark is considered a no spark condition.
- Verify the spark tester sparks while cranking the engine.
- If the spark tester does not spark
Refer to Electronic Ignition System Diagnosis .
- If the spark tester sparks
- If the spark tester does not spark
- Ignition OFF, install the CH-48027 Digital Pressure Gauge. Refer to Fuel Pressure Gauge Installation and Removal .
- If the engine is too hot, high fuel pressure readings may result due to hot soak fuel boiling. Allow the engine coolant temperature to cool to less than 60° C (150° F) before attempting to verify fuel pressure.
- The fuel pump may need to be commanded ON a few times in order to obtain the highest possible fuel pressure.
- Additional DTCs may set when using the fuel pump output control.
- Ignition ON.
- Command the Fuel Pump Relay On several times with a scan tool.
- Verify that the fuel pressure is between 345 - 414 kPa (50 - 60 psi) with the fuel pump running.
- If not within the specified range
Refer to Fuel System Diagnosis .
- If within the specified range
- If not within the specified range
- Verify that the fuel pressure does not decrease greater than 34 kPa (5 psi).in 1 min.
- If not within the specified range
Refer to Fuel System Diagnosis .
- If within the specified range
- If not within the specified range
- Verify the conditions listed below do not exist:
- Collapsed air intake duct to the throttle body
- Restricted air filter element
- Spark plugs for being fouled
- A skewed manifold absolute pressure (MAP) sensor - Refer to DTC P0106 .
- A skewed engine coolant temperature (ECT) sensor - Refer to DTC P0116 .
- Exhaust system restricted - Refer to RESTRICTED EXHAUST .
- Fuel contamination - Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
- Engine mechanical condition - Refer to Symptoms - Engine Mechanical , or Engine Compression Test .
- If a condition exists
Repair as necessary.
- If no condition exists
- All OK.
NOTE:
NOTE: