My 2005 base model C6 which I've had for 18 months now , has been running fine , however I moved to South East Spain last year, and you only have to look at the car after cleaning it to see it covered in a fine dust again . As such i thought I'd carry out a bit of preventative maintenance and clean the Throttle body and MAF sensor using the appropriate cleaners for each , removing both from the car and without moving the TB butterfly . Nice easy job ,had it done and dusted (sic) and all back together within an hour ...however , I took the car out for a run and all seemed good at first , a 5 minute drive to the motorway and then a good 40k of clear road to give it a blast , however coming off the motorway , and to a quick stop, the car went into "Reduced Power Mode ". Once the car has been switched off and left for a minute or two its starts again fine , but on slow roads it soon drops back to "Reduced Engine Power " .I've tried a "relearn ", which id seen on a different forum ...ie 3 min idle , off for 1 min, another 3 min idle a couple of times and I'm still suffering the same issue ...Good at speed on the Motorway but drops into "REP" mode when it slows . As said , everything was fine before I did the clean .. Any ideas anyone ? Thanks
Throttle body / MAF issues !
- Thread starter Museo
- Start date
teamzr1
Supporting vendor
What products did you use to clean the MAF and TB ?
Did you use a MAF cleaner product and not over spray the very thin exposed sensor wires or break them
Disconnect the connector from the MAF and check to make sure neither the wiring pins nor MAF pins did not get bent
or pushed inwards and make sure when connecting the connector again that fully seated to the MAF
Did you take the MAF off, if so make sure the airflow arrow is pointing to the TB as if on backwards would cause problems
Closely look that the airbridge from the aircleaner, to the TB is on correctly, look at the bottom side to make sure
the rubber couplers did not get rolled over and is causing unmetered airflow which would confuse the PCM
Any error codes showing on the DIC ?
Looking at my C5 notice how the MAF is positioned
Did you use a MAF cleaner product and not over spray the very thin exposed sensor wires or break them
Disconnect the connector from the MAF and check to make sure neither the wiring pins nor MAF pins did not get bent
or pushed inwards and make sure when connecting the connector again that fully seated to the MAF
Did you take the MAF off, if so make sure the airflow arrow is pointing to the TB as if on backwards would cause problems
Closely look that the airbridge from the aircleaner, to the TB is on correctly, look at the bottom side to make sure
the rubber couplers did not get rolled over and is causing unmetered airflow which would confuse the PCM
Any error codes showing on the DIC ?
Looking at my C5 notice how the MAF is positioned
Last edited:
Hi TeamZR1...
I used "Liqui Moly " air flow sensor cleaner on the MAF and "Motul" Throttle Body Cleaner on the TB...both are undamaged and the MAF is facing the correct way. All pins and connections are in good order and the car was running fine before hand ( I know ...if it aint broke , dont fix it )...No Codes showing on the DIC either !!!
I used "Liqui Moly " air flow sensor cleaner on the MAF and "Motul" Throttle Body Cleaner on the TB...both are undamaged and the MAF is facing the correct way. All pins and connections are in good order and the car was running fine before hand ( I know ...if it aint broke , dont fix it )...No Codes showing on the DIC either !!!
teamzr1
Supporting vendor
IF no DTCs are tripping, then I agree,
Have to check very closely for an unmetered air leak from aircleaner to coupler attached to the TB
As I mentioned, the rubber coupler to TB tends to fold over at the bottom and pulls in unmetered air
Did not take the TB off during cleaning or disconnected the wiring connectors off the TPS or the drive by wire ?
I did take the TB off and disconnected the wiring …
teamzr1
Supporting vendor
No real reason to take TB for cleaning as simple spray cleaner would do fine
Check those wiring connectors as to any bent PIDs
Possible the vacuum hoses that go to TB not fully connected?
TRY these :
Perform the following procedure to return the TPS to the correct position:
Sync TPS to PCM
With ign key off, unplug wiring connector from TPS
Turn ign key on but engine OFF
Wait a few seconds, could trip a TPS DTC
Turn key off, connect TPS wiring connector
Start engine and if need be clear DTC
Idle relearns
Automatic Transmission:
1 Turn off the ignition
2 Restore the PCM battery (if was disconnected)
3 Turn Off the AC controls
4 Set the parking brake and block the drive wheels
5 Start the engine
6 Allow the engine coolant temperature to reach 176 degrees F
7 Shift the transmission selector into the drive range
8 Allow the engine to idle for 5 minutes
9 Turn on the AC controls (Omit for 2000-02 model)
10 Allow the engine to idle for 5 minutes (Omit for 2000-02 model)
11 Shift the transmission selector into Park
12 Allow the engine to idle for 5 minutes (Omit for 2000-02 model)
13 Turn off the AC controls (Omit for 2000-02 model)
14 Allow the engine to idle for 5 minutes
15 Turn off the engine for 15 seconds
Manual Transmission:
1 Turn Off the ignition
2 Restore the PCM battery feed
3 Turn Off the AC controls
4 Set the parking brake and block the drive wheels
5 Transmission in neutral
6 Start the engine
7 Allow the engine coolant temperature to reach 176 degrees F
8 Turn on the AC controls (Omit for 2000-02 model)
9 Allow the engine to idle for 5 minutes (Omit for 2000-02 model)
10 Turn off the AC controls (Omit for 2000-02 model)
11 Allow the engine to idle for 5 minutes
12 Turn off the engine for 15 seconds