S60 Electrics: Fault code help?

[Knockwurst]

Hi guys,

My 2001 2.4T S60 has logged the following codes. I have cleared them to make sure they are not spurious, but they eventually come back.

CCM 0021 - Air quality sensor / Blower fan power unit. The climate and all its functions seems to work ok.

PDM 0010 - Central locking motor M1. Signal too low /Central locking motor M1. Signal too low or signal missing /Control panel. Open-circuit. It seems like the door locks ok.

CEM 6A02 - Right rear door unlocked. I check the door each time I lock the car and it has never remained unlocked- could this be a deadlock error?

ECM 3420 - Knock sensor rear. I had a bad start/stumble the other morning, but the car seems to be running ok apart from a very mild erratic idle (ETM has been changed). The fault code doesn't log each trip, it took over a week for it to come back again. There is no audible knock from the engine.

If anyone can shed some light on the above, I'd be grateful. I don't really want to start swapping sensors / door locks if there is another option! (I am starting to think I shouldn't have bought the PPC code reader )

[940dad]

Hi
The ccm 0021 code means that the air senser in the air intake is faulty, this little device controls the vent flap on the intake. It closes it if there are polutents in the air and stops them entering the car. You will find it under the black trim below the windscreen inside the air intake on the right hand side (looking from the front) well it is on my 2002 V70. Just changed mine for the same code.
Not sure about the others?

[Knockwurst]

thanks 940dad. Do you mind saying how much it was to replace?

[940dad]

I replaced it myself, the cost of the sensor from volvo is approx £139.00 + vat. I managed to find a secondhand one which cost £20+vat You may get away with just blowing the sensor out with compressed air?

[Chris_Rogers]

You may find this link helpful for wiring diagrams:

http://www.mojevolvo.pl/wiki/Volvo_S60

Some fault code info:

Condition

Diagnostic trouble code (DTC) DDM/PDM–0010 is stored if the control module registers a short-circuit to ground or an open-circuit in signal cable M1.
Diagnostic trouble code (DTC) DDM/PDM-0010 can be diagnosed when the central locking locks or unlocks.

Substitute value
-None.

Possible source

-Signal cable M1 is short-circuited to ground
-Open-circuit in signal cable M1.

Fault symptom[s]
-The central locking system does not function at all.

If the central electronic module (CEM) detects a high signal from the lock position sensor 15 seconds after locking, diagnostic trouble code CEM-6A02 is displayed

Possible source

-The lock has stuck in unlocked position
-Open circuit in lock sensor signal wire
-Lock position sensor signal wire short circuited to voltage supply
-Relay fault
-Open circuit on relay supply/defective fuse
-Fault in locking motor circuit
-Fault in rear electronic module (REM).

Fault symptom[s]
-A door does not lock / open.

Diagnostic trouble code (DTC) ECM-3420 is stored if the engine speed (RPM) is over 3000 rpm, the engine coolant temperature (ECT) is above 40°C and the signal from the rear knock sensor (KS) is too high or too low.

Substitute value
-ignition retarded for safety reasons
-reduced boost pressure

Possible source

Signal too high:
-short-circuit to supply voltage in the signal cable
-worn engine
Signal too low:
-open-circuit in signal cable
-contact resistance in terminals
-defective knock sensor (KS)
-short-circuit between knock sensor (KS) signal cables

Fault symptom[s]
-none