P1654

P1654

Coolant switch-over valve driver, above limit value

Diagnostic conditions
- Supply voltage > 7 V
- Engine running
- Coolant change-over valve activated (ATF cooler closed)
- for 997 coolant temperature < 90 °C (194 °F) and ATF temperature < 83 °C (181 °F)
- for 987 coolant temperature < 80 °C (176 °F) and ATF temperature < 75 °C (167 °F)

Possible fault causes
- Short circuit to B+ in control line
- Coolant switch-over valve faulty
- DME control module faulty