So, my car is surging, most notably at idle. It runs marginally well under acceleration. It also issued a code P0134 which I found to be a front O2 sensor failure. So I replaced that sensor with a new Bosch 1/2 hour ago. The surge is still present. I cannot find that P1238 code in the Code List on this site. Anybody know?
I would think Throttle Body, but my original one was replace a few months ago.
The car was running well just a day ago. But that surge occasionally would show up once or twice and then dissapear altogether, no code being thrown.
Code P1238 ? 2001 C70 Coupe 2.3L
-
foresthump
- Posts: 27
- Joined: 30 December 2011
- Year and Model: C70 2001
- Location: South Boston, Va.
-
villagepc
- Posts: 89
- Joined: 15 December 2008
- Year and Model: 98 V70m | Stage III
- Location: Florida
- Has thanked: 3 times
- Been thanked: 2 times
Hopefully you have the means to clear codes (via odb2) because monkeying this way will definitely set codes.
Check your mass airflow sensor first - start the car, then unplug it. See if the idle clears up.
Also check hoses related to the turbo junk - if applicable - (turbo control valve / wastegate / boost control solenoid) - P1238 points to the TCV, but in reality it means (most likely) air leak in the turbo hoses - or a failing TCV / BCS.
Check around for any other hoses that might be unplugged / pinched / cracked.
Check your mass airflow sensor first - start the car, then unplug it. See if the idle clears up.
Also check hoses related to the turbo junk - if applicable - (turbo control valve / wastegate / boost control solenoid) - P1238 points to the TCV, but in reality it means (most likely) air leak in the turbo hoses - or a failing TCV / BCS.
Check around for any other hoses that might be unplugged / pinched / cracked.
____________________________________________
1998 V70 T5M R Clone | IPD / ARD Stage 3
2008 S80 3.2 - not too shabby
1991 740 Turbo - 2.5" lift, 100% madness
1998 V70 T5M R Clone | IPD / ARD Stage 3
2008 S80 3.2 - not too shabby
1991 740 Turbo - 2.5" lift, 100% madness
-
villagepc
- Posts: 89
- Joined: 15 December 2008
- Year and Model: 98 V70m | Stage III
- Location: Florida
- Has thanked: 3 times
- Been thanked: 2 times
and lookey here.. viewtopic.php?f=9&t=79307 - another 1238 post !
____________________________________________
1998 V70 T5M R Clone | IPD / ARD Stage 3
2008 S80 3.2 - not too shabby
1991 740 Turbo - 2.5" lift, 100% madness
1998 V70 T5M R Clone | IPD / ARD Stage 3
2008 S80 3.2 - not too shabby
1991 740 Turbo - 2.5" lift, 100% madness
-
RickHaleParker
- Posts: 7129
- Joined: 25 May 2015
- Year and Model: See Signature below.
- Location: Kansas
- Has thanked: 8 times
- Been thanked: 958 times
P1238 =ECM-6806 Turbocharger (TC) control system flow fault. Flow too low/ too high.
Diagnostic trouble code (DTC) information
Condition
If engine speed (RPM) is above 3500 rpm and the engine is operating at a high load, the control signal to the turbocharger (TC) control valve is at maximum and the boost pressure (from boost pressure sensor) is lower than a designated value (approximately 20 kPa (2.9 psi) under normal boost pressure - signal too low).
If the air mass (from mass air flow (MAF) sensor) is higher than a desired value (signal too high) it is interpreted as a fault and diagnostic trouble code (DTC) ECM-6806 is stored.
Substitute value
reduced boost pressure
Possible source
Signal too high:
Fault symptoms
none
Diagnostic trouble code (DTC) information
Condition
If engine speed (RPM) is above 3500 rpm and the engine is operating at a high load, the control signal to the turbocharger (TC) control valve is at maximum and the boost pressure (from boost pressure sensor) is lower than a designated value (approximately 20 kPa (2.9 psi) under normal boost pressure - signal too low).
If the air mass (from mass air flow (MAF) sensor) is higher than a desired value (signal too high) it is interpreted as a fault and diagnostic trouble code (DTC) ECM-6806 is stored.
Substitute value
reduced boost pressure
Possible source
Signal too high:
- air leakage after turbocharger (TC)
- hoses between turbocharger (TC) and turbocharger (TC) control valve respectively turbocharger (TC) control valve and pressure servo are loose or are blocked/damaged
faulty turbocharger (TC) control valve
faulty boost pressure control (BPC) valve pressure servo
sticking boost pressure control (BPC) valve
Fault symptoms
none
⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙
1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package.
2003 S40, B4204T3, 14T twin scroll AW55-50/51SN, Siemens EMS 2000.
2004 S60R, B8444S TF80 AWD. Yamaha V8 conversion
2005 XC90 T6 Executive, B6294T, 4T65 AWD, Bosch Motronic 7.0.
1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package.
2003 S40, B4204T3, 14T twin scroll AW55-50/51SN, Siemens EMS 2000.
2004 S60R, B8444S TF80 AWD. Yamaha V8 conversion
2005 XC90 T6 Executive, B6294T, 4T65 AWD, Bosch Motronic 7.0.
-
- Similar Topics
- Replies
- Views
- Last post