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 Open/Short Circuit To Ground On Control Signal Cable Between ECC/MCC Control Module And ECM
- No diagnostic trouble codes (DTCs) stored.
- The fault is permanent
- No mechanical fault in air conditioning (A/C) system.
NOTE:
This test is designed for the electrical circuit between ECC/MCC control module and engine control module (ECM) via the low pressure switch.
Possible Source
- Open-circuit or short-circuit to ground on control signal cable between ECC control module #A3 (MCC control module #B22) and engine control module (ECM).
- Contact resistance in terminals.
- Defective low-pressure switch.
Fault symptom[s]
- The passenger compartment temperature does not correspond to the level selected on the temperature control.