Engine Cranks but Does Not Run Chart 1 of 4

Circuit Description

In order to diagnose this system, battery voltage must be above 11 volts. Cranking speed of the starter must be normal and fuel quality and quantity should be checked. When the ignition is ON and crank pulses are received, IC pulses are delivered to the EI module. Also, pulses are delivered to the injectors when crank pulses are received.

Diagnostic Aids

Water in the fuel causes a no start during cold weather starts.

An ECT sensor reading incorrectly can cause a no start or a hard start. This may be due to over-fueling or under-fueling.

ECT may be compared to IAT temperature with the scan tool if the engine has cooled overnight at ambient temperature. They should be within 4 degrees of each other with the ignition ON and the key OFF.

If the MAP sensor 5 volt line is shorted to ground, a DTC 1635 will set. Diagnose this DTC first.

Test Descriptions

1. If an injector fuse is blown, all 4 injector DTCs will set when the ignition is turned ON.
2. If the 5 volt reference circuit becomes shorted to ground it will result in a no start.
3. An IC fault will cause 2 mating cylinders to not spark and may result in a no start, especially if the engine is cold.
4. An EGR stuck open may result in a no start.
5. If no RPM is indicated, spark and injectors will not be turned ON. The is no 7x signal to the PCM from the CKP sensor.
6. Under normal cranking conditions, the 7x counter should count up to 14, 2 cranking revolutions, and reset to 0 when a cylinder #4 signal is received.
7. Check for a flooded engine, or fouled plugs.

Important

Always check fuses first in the IPJB and the UHJB.

If the MAP sensor 5 volt line is shorted to ground, a DTC P1635 will set. Diagnose this DTC first.