Fault-Tracing Information

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

Condition

Fig 1: Identifying Control Module Connector And 6-Pin Heater Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

Diagnostic trouble codes (DTCs) missing in additional heater control module.

Possible Source

Open-circuit in the D+ cable.
Short-circuit to ground in the D+ cable.
Contact resistance in control module connector.
Low battery voltage.
Contact resistance in 6-pin heater connector.

Fault symptom[s]

Poor heating in passenger compartment.