This symptom-driven test is performed if a “N” is displayed on the gear display with no Active or Inactive codes and the vehicle does not crank.
The Hybrid Control Module (HCM) receives the input to crank from Pin 20 on the HCM 38-Way Connector, which is wired to the Key Switch. The HCM normally powers the High-Voltage Motor/Generator to start the engine. If the hybrid system is offline, the HCM uses the standard 12-Volt Starter by energizing the 12-Volt Cranking Relay. This relay then provides battery power to Pin 30 of the Start Enable Relay, which then powers the Starter Solenoid.
Note: This symptom-based test should only be performed if directed here from the Diagnostic Procedure and there are no Active fault codes.
Eaton Fuller Hybrid Transmission Engine Crank Test Detection
The following symptoms may have been experienced:
- Vehicle does not crank or there is a solid “N” in the Gear Display.
This fault code can be caused by any of the following:
- 12-Volt Cranking Relay
- Start Enable Relay
- Vehicle Harness
- Engine Starter
- 12-volt batteries
- Key Switch input to Pin 20 of the HCM