2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1593

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1593

The high voltage interlock circuit (HVIC) is utilized to verify high voltage component integrity. HVIC is a circuit loop that passes through certain

high voltage components. HVIC is used to determine if access to high voltage components is being attempted. The opening of these high voltage

components causes HVIC to open. The battery energy control module (BECM) sources about 12 mA of current on the 5V HVIC loop. The BECM

monitors both the HVIC source circuit current and the HVIC return circuit current in order to detect circuit faults. Both motor control modules

(MCMs) monitor the circuit for current in order to detect an open condition. When the BECM and/or the MCMs sense conditions such as a loss of

HVIC current, the high voltage contactor relays are commanded open by the hybrid powertrain control module (HPCM).

Conditions for Running the DTC

P1B05 and P1B06

* Ignition voltage is 8-18 volts.

* Wake up signal is active.

* BECM is supplying current on HVIC circuit. This normally occurs when HV contactor relays are closed.

P1AE2, P1AE3 and P1AE4

* Ignition voltage is 9-18 volts.

* Wake up signal is active.

* BECM is supplying current on HVIC circuit. This normally occurs when HV contactor relays are closed.

Conditions for Setting the DTC

P1B05 and P1B06

* The MCM does not detect HVIC current flow.

* DTC P1B05 and P1B06 set within 1 second when the above condition is met.

P1AE2

* The BECM detects HVIC source current is less than 5 mA and HVIC return current is less than 5 mA.

* DTC P1AE2 sets within 1 second when the above condition is met.

P1AE3

* The BECM detects HVIC source current is between 5-18 mA and HVIC return current is less than 5 mA.

* DTC P1AE3 sets within 1 second when the above condition is met.

P1AE4

* The BECM detects HVIC source current is less than 5 mA and HVIC return current is greater than 35 mA.

* DTC P1AE4 sets within 1 second when the above condition is met.

Action Taken When the DTC Sets

* DTCs P1B05, P1B06, P1AE2, P1AE3, P1AE4 are Type C DTCs.

* The HPCM commands the BECM to open the high voltage contactor relays when vehicle speed is less than 5 km/h (3 mph) for 6 seconds.

Conditions for Clearing the DTC

DTCs P1B05, P1B06, P1AE2, P1AE3, P1AE4 are Type C DTCs.

Diagnostic Aids

* Test for a fully engaged high voltage manual disconnect lever whenever an open HVIC condition is observed. The manual disconnect lever

must be pressed down fully in order to engage the HVIC terminals.

* The BECM HVIC source and HVIC return circuit current sensors may not measure actual circuit current with the same accuracy. The BECM

HVIC Source parameter may indicate less current than the BECM HVIC Return parameter for this reason. Measuring actual HVIC current

with a DMM may also not compare directly to the parameter display.

* The HVIC detects removal of the following components:

- The drive motor generator control module sight shield

- The transmission 3 phase cable cover

- The high voltage manual disconnect lever

- The hybrid battery terminal extension cover assembly

* The HVIC is also routed through several inline connectors.

* With the ignition in the OFF position, the BECM will source the HVIC current for 5 minutes every time a vehicle door is opened.

Reference Information

Schematic Reference

Hybrid Controls Schematics ()

Connector End View Reference