cooling fans on while in diagnostic mode...

KING_3 · Post by **KING_3** » Thu Mar 29, 2007 3:01 pm

what seems to be the prob with my espero
i've just put it in diagnostic mode (by grounding disgnosting terminal in the ECM) and the moment i turn the key to IGNition, the cooling fans switch on
what are the possible causes for the switching of the fans?

thanks for your help

Daniel · Post by **Daniel** » Thu Mar 29, 2007 4:14 pm

That's normal. No problem here.

Daniel

KING_3 · Post by **KING_3** » Fri Mar 30, 2007 6:29 pm

thanks
but what if even i'm not in diagnostic mode and then turn the key to ON, the fans would switch on already with the engine not running
and when i start the engine and switch the A/C, the clutch won't engage

sorry i made a mistake in my first post, "IGNition" should be replaced by "ON position" of the key

Daniel · Post by **Daniel** » Fri Mar 30, 2007 7:51 pm

KING_3 wrote:thanks
but what if even i'm not in diagnostic mode and then turn the key to ON, the fans would switch on already with the engine not running
and when i start the engine and switch the A/C, the clutch won't engage

sorry i made a mistake in my first post, "IGNition" should be replaced by "ON position" of the key

>but what if even i'm not in diagnostic mode and then turn the key to ON, the fans would switch on already with the engine not running<

If fans starts with cold engine check the temperature sensor and/or relative wiring for a short-circuit.

>and when i start the engine and switch the A/C, the clutch won't engage<

Defective A/C switch, refrigerant pressure low, fuse, relay,...

Daniel

KING_3 · Post by **KING_3** » Fri Mar 30, 2007 8:06 pm

do you think both problems are related?
also, i forgot to mention, both problems are intermittent, but they happen together

Daniel · Post by **Daniel** » Sat Mar 31, 2007 11:34 am

Can you check the following?

Ground pin B of ALDL connector and key to ON(not start): fan(s) go on at low speed, fuel pump is on, code 12 is showed 3 time by the CHECK light.
Do you read other code(s) after 12?
Do you have driveability problem?
Do you have poor fuel mileage?

Since the problem is intermittent I would also check:
-all related connectors for mating/bad contacts.
-charge of A/C refrigerant.
-A/C pressure sensor/connector.
-CTS (coolant temperature sensor) resistance value directly on it's two pins A&B connector. Sould be approx 4450 ohms @ 15°C/59°F or compare value with ECTS (engine coolant temperature sensor) single pin one. Disconnect them before measuring with a ohmmeter.
-pinched wiring/harness.
FYI CTS sends temp info to the computer that commands fans relays. ECTS only drive panel instrument temp gauge.

Daniel