turborx8

iTrader: (1)

My car keeps going into limp-mode so I bought a code scanner and this was the error.

P2102 - Throttle Actuator Control Motor Circuit Low

Any idea what would cause this problem?

zoom44

bad throttle. bad connectors at the throttle.

have the intake off recently before this started?

turborx8

iTrader: (1)

Nope. Intake manifold has never been taken off before. What connector should I be checking exactly?

turborx8

iTrader: (1)

Can anyone take a stab at this?

turborx8

iTrader: (1)

I can't seem to figure this out.

I keep clearing the code but it keeps happening!

zoom44

to the dealer you go.

VashGS

Maybe the actuator motor is burning out? This is part of the drive by wire system. I don't know how to test the unit though. Inspect wires for rat chew, remove clean and reconnect connector to the throttle body. Inspect throttle body vac hoses.

dannobre

iTrader: (3)

I would try another throttle body...either borrow one..or find a used one..that is the most likely problem

Either that or a wiring harness issue

turborx8

iTrader: (1)

Rat chew... hmmm.. you might be on to something here.

MazdaManiac

iTrader: (3)

Swap throttle bodies.
Check the pin-to-pin continuity of the TB harness to the PCM.
But, most importantly, check the three ground points (upper intake manifold, PCM sensor near the strut bar and on the radiator cross-member).
Those grounds almost ALWAYS cause the sensor failures.

valtech

DTC P2102
Throttle actuator power supply line circuit low input

DETECTION CONDITION
•The PCM monitors the input voltage from the drive-by-wire relay when the PCM turns the drive-by-wire relay on. If the input voltage is less than 5.0 V, the PCM determines that the drive-by-wire relay control circuit voltage is low.

Diagnostic support note
•This is a continuous monitor (CCM).

•The MIL illuminates if the PCM detects the above malfunction condition in the first drive cycle.

•PENDING CODE is available if the PCM detects the above malfunction condition.

•FREEZE FRAME DATA is available.

•The DTC is stored in the PCM memory.

POSSIBLE CAUSE
•Drive-by-wire relay malfunction

•Connector or terminal malfunction

•Open circuit in wiring harness between main relay terminal C and drive-by-wire relay terminal A

•Short to ground in wiring harness between main relay terminal C and drive-by-wire relay terminal A

•Open circuit in wiring harness between drive-by-wire relay terminal E and PCM terminal 5H

•Open circuit in wiring harness between battery positive terminal and drive-by-wire relay terminal D

•Short to ground in wiring harness between battery positive terminal and drive-by-wire relay terminal D

•Open circuit in wiring harness between drive-by-wire relay terminal C and PCM terminal 4C

•Short to ground in wiring harness between drive-by-wire relay terminal C and PCM terminal 4C

•PCM malfunction

VashGS

lol yea it sounds funny but they will chew up wire insulation and vac hoses.
It's rare but happens.

turborx8

iTrader: (1)

I don't have a spare throttle body in my back pocket to give that a try so I am gonna look for some chewed up wire first. I did find a small nest under my engine cover and there was a rubber vac hose with some chew marks in it so I bet that is my problem.

turborx8

iTrader: (1)

Update:

I replaced the throttle body with a brand new one. After 900km the code came back and was consistently getting triggered. I took it back to have the entire PCM replaced and after a few thousand km its back again.

If replacing the throttle body and PCM did not solve the problem, what could it be?

Also every wire from the PCM to the throttle have been checked and each wire has good voltage.

Harlan

iTrader: (3)

If it's not the throttle body and not the PCM that means it's either the wiring harness or grounds. Both have been mentioned already. It may not show up by simply checking voltage because it's obvious it's intermittent.

Harlan

iTrader: (3)

Crap, didn't see dates. Well, hope that helps somebody.