IPD sale XeMODeX - Experts in Volvo Electronics
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy anything with this and it helps MVS!

94 850T check engine light while accelerating

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

User avatar
henrysin44
Posts: 118
Joined: Sun Apr 12, 2015 4:14 pm
Year and Model: 1994 Volvo 855 Turbo
Location: Guilford, CT USA
Has thanked: 2 times
Been thanked: 3 times
Sweden
henrysin44

94 850T check engine light while accelerating

Post by henrysin44 » Tue May 12, 2020 4:45 pm

My check engine light comes on only during acceleration, the light turns off once off the throttle/just coasting. Its almost like the throttle is a check engine light switch lol. It doesn't always come on during light acceleration but always under medium to full throttle.
Whats weird is theres no codes set at all, not even pending codes, the light doesn't flash, and the car runs perfect with no loss of power or hesitation.
http://shealabs.net
Daily driver Black 1994 Volvo 855 2.3L Turbo - manual swapped, turbo swapped, green injectors, custom M4.4 Tune, de-catted, custom two-tone interior, V70R seats & rims
Teal 1994 Volvo 855 2.5L N/A Manual Transmission (the back up daily and parts car) - Runs and Drives but the engine knocks
Silver 1997 Honda CRV 2.0 AWD - its in a very sorry condition, but drives
Silver 2003 Subaru Forester 2.5L N/A AWD - Leaks everything

User avatar
misha
Posts: 4458
Joined: Sun Dec 07, 2008 4:09 pm
Year and Model: '97 850 2.5 20v
Location: Serbia
Has thanked: 59 times
Been thanked: 153 times
Serbia
misha

Re: 94 850T check engine light while accelerating

Post by misha » Tue May 12, 2020 4:53 pm

Does this happens only in high rpms(5-6k rpms) or even on lower rpms with full throttle?

Did you read the codes from instrument cluster?
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
'91 Citroen XM 2.0 SI /fully equipped/mandarine red metallic
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

User avatar
henrysin44
Posts: 118
Joined: Sun Apr 12, 2015 4:14 pm
Year and Model: 1994 Volvo 855 Turbo
Location: Guilford, CT USA
Has thanked: 2 times
Been thanked: 3 times
Sweden
henrysin44

Re: 94 850T check engine light while accelerating

Post by henrysin44 » Tue May 12, 2020 5:49 pm

misha wrote:
Tue May 12, 2020 4:53 pm
Does this happens only in high rpms(5-6k rpms) or even on lower rpms with full throttle?

Did you read the codes from instrument cluster?
Most of the time it happens in around 3K and above and no I haven't checked the instrument cluster codes, ill check them now. My car has an upgraded ECU so its OBD2 only for engine trouble codes.
http://shealabs.net
Daily driver Black 1994 Volvo 855 2.3L Turbo - manual swapped, turbo swapped, green injectors, custom M4.4 Tune, de-catted, custom two-tone interior, V70R seats & rims
Teal 1994 Volvo 855 2.5L N/A Manual Transmission (the back up daily and parts car) - Runs and Drives but the engine knocks
Silver 1997 Honda CRV 2.0 AWD - its in a very sorry condition, but drives
Silver 2003 Subaru Forester 2.5L N/A AWD - Leaks everything

User avatar
henrysin44
Posts: 118
Joined: Sun Apr 12, 2015 4:14 pm
Year and Model: 1994 Volvo 855 Turbo
Location: Guilford, CT USA
Has thanked: 2 times
Been thanked: 3 times
Sweden
henrysin44

Re: 94 850T check engine light while accelerating

Post by henrysin44 » Tue May 12, 2020 5:53 pm

misha wrote:
Tue May 12, 2020 4:53 pm
Does this happens only in high rpms(5-6k rpms) or even on lower rpms with full throttle?

Did you read the codes from instrument cluster?
1-2-2 and 1-3-2 was stored in A7 inst cluster
http://shealabs.net
Daily driver Black 1994 Volvo 855 2.3L Turbo - manual swapped, turbo swapped, green injectors, custom M4.4 Tune, de-catted, custom two-tone interior, V70R seats & rims
Teal 1994 Volvo 855 2.5L N/A Manual Transmission (the back up daily and parts car) - Runs and Drives but the engine knocks
Silver 1997 Honda CRV 2.0 AWD - its in a very sorry condition, but drives
Silver 2003 Subaru Forester 2.5L N/A AWD - Leaks everything

User avatar
misha
Posts: 4458
Joined: Sun Dec 07, 2008 4:09 pm
Year and Model: '97 850 2.5 20v
Location: Serbia
Has thanked: 59 times
Been thanked: 153 times
Serbia
misha

Re: 94 850T check engine light while accelerating

Post by misha » Tue May 12, 2020 6:13 pm

Did you had this problem before ecu upgrade?

1-2-2 temperature sensor interval too long
1-3-2 engine speed sensor signal incorrect

How did you upgraded ecu...swap from a newer model(which year) or flashed?
Clear the codes,go for a spin and check will they come back.

EDIT...i just saw the signature...it's a custom M4.4 tune.
Anyway...clear the codes and see if they comes back.

How do you check OBDII codes since '94 doesn't have OBDII port?
Did you added it?
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
'91 Citroen XM 2.0 SI /fully equipped/mandarine red metallic
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

User avatar
henrysin44
Posts: 118
Joined: Sun Apr 12, 2015 4:14 pm
Year and Model: 1994 Volvo 855 Turbo
Location: Guilford, CT USA
Has thanked: 2 times
Been thanked: 3 times
Sweden
henrysin44

Re: 94 850T check engine light while accelerating

Post by henrysin44 » Tue May 12, 2020 6:32 pm

misha wrote:
Tue May 12, 2020 6:13 pm
Did you had this problem before ecu upgrade?

1-2-2 temperature sensor interval too long
1-3-2 engine speed sensor signal incorrect

How did you upgraded ecu...swap from a newer model(which year) or flashed?
Clear the codes,go for a spin and check will they come back.
I flashed a 1998(maybe 99) Turbo ECU (M4.4) about a year ago, its a stock 850 T5 BIN for manual transmissions, have not had any problems with it, even have working A/C. I'm pretty sure these codes are new as I had the battery unhooked for a few hours last week. Although my RPM sensor is a knock-off from AutoZone so I'd bet that code is genuine sense the sensor is not BOSCH.

EDIT: I have no idea why my 94 has an OBD2 and OBD1, but it is factory. I think the very late 94 models introduced the OBD2 port
http://shealabs.net
Daily driver Black 1994 Volvo 855 2.3L Turbo - manual swapped, turbo swapped, green injectors, custom M4.4 Tune, de-catted, custom two-tone interior, V70R seats & rims
Teal 1994 Volvo 855 2.5L N/A Manual Transmission (the back up daily and parts car) - Runs and Drives but the engine knocks
Silver 1997 Honda CRV 2.0 AWD - its in a very sorry condition, but drives
Silver 2003 Subaru Forester 2.5L N/A AWD - Leaks everything

User avatar
misha
Posts: 4458
Joined: Sun Dec 07, 2008 4:09 pm
Year and Model: '97 850 2.5 20v
Location: Serbia
Has thanked: 59 times
Been thanked: 153 times
Serbia
misha

Re: 94 850T check engine light while accelerating

Post by misha » Tue May 12, 2020 6:37 pm

So...are you saying that CEL thing during acceleration appeared AFTER battery was disconnected?

Aftermarket sensors are usually out of range from the factory and they can't be trusted.
Code is for it....incorrect signal.

That can be the source of your problems.
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
'91 Citroen XM 2.0 SI /fully equipped/mandarine red metallic
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

User avatar
henrysin44
Posts: 118
Joined: Sun Apr 12, 2015 4:14 pm
Year and Model: 1994 Volvo 855 Turbo
Location: Guilford, CT USA
Has thanked: 2 times
Been thanked: 3 times
Sweden
henrysin44

Re: 94 850T check engine light while accelerating

Post by henrysin44 » Tue May 12, 2020 6:49 pm

misha wrote:
Tue May 12, 2020 6:37 pm
So...are you saying that CEL thing during acceleration appeared AFTER battery was disconnected?
Ya wasn't comming on prior to that, actually I disconnected the battery to pull the cluster, odometer gear needed replacing and there were also a few bulbs burnt out so I replaced every single bulb (don't want to be back in there again). Don't exactly know how that could cause a CEL after a week but the cluster has always acted up for years now.

As a side note not all the lights come up when key is in position 2, or while starting, but all are functional. Video: https://www.youtube.com/watch?v=eDVhA78yTyI
Last edited by henrysin44 on Tue May 12, 2020 6:52 pm, edited 1 time in total.
http://shealabs.net
Daily driver Black 1994 Volvo 855 2.3L Turbo - manual swapped, turbo swapped, green injectors, custom M4.4 Tune, de-catted, custom two-tone interior, V70R seats & rims
Teal 1994 Volvo 855 2.5L N/A Manual Transmission (the back up daily and parts car) - Runs and Drives but the engine knocks
Silver 1997 Honda CRV 2.0 AWD - its in a very sorry condition, but drives
Silver 2003 Subaru Forester 2.5L N/A AWD - Leaks everything

User avatar
henrysin44
Posts: 118
Joined: Sun Apr 12, 2015 4:14 pm
Year and Model: 1994 Volvo 855 Turbo
Location: Guilford, CT USA
Has thanked: 2 times
Been thanked: 3 times
Sweden
henrysin44

Re: 94 850T check engine light while accelerating

Post by henrysin44 » Tue May 12, 2020 6:50 pm

henrysin44 wrote:
Tue May 12, 2020 6:49 pm
misha wrote:
Tue May 12, 2020 6:37 pm
So...are you saying that CEL thing during acceleration appeared AFTER battery was disconnected?
Ya wasn't comming on prior to that, actually I disconnected the battery to pull the cluster, odometer gear needed replacing and there were also a few bulbs burnt out so I replaced every single bulb (don't want to be back in there again). Don't exactly know how that could cause a CEL after a week but the cluster has always acted up for years now.

As a side note not all the lights come up when key is in position 2, or while starting, but all are functional. Video: https://www.youtube.com/watch?v=eDVhA78yTyI The rattling bang sound is my exaust pipe
http://shealabs.net
Daily driver Black 1994 Volvo 855 2.3L Turbo - manual swapped, turbo swapped, green injectors, custom M4.4 Tune, de-catted, custom two-tone interior, V70R seats & rims
Teal 1994 Volvo 855 2.5L N/A Manual Transmission (the back up daily and parts car) - Runs and Drives but the engine knocks
Silver 1997 Honda CRV 2.0 AWD - its in a very sorry condition, but drives
Silver 2003 Subaru Forester 2.5L N/A AWD - Leaks everything

User avatar
RickHaleParker
Posts: 4522
Joined: Mon May 25, 2015 2:30 pm
Year and Model: See Signature below.
Location: Kansas
Has thanked: 3 times
Been thanked: 578 times
United States of America
RickHaleParker

Re: 94 850T check engine light while accelerating

Post by RickHaleParker » Tue May 12, 2020 6:57 pm

henrysin44 wrote:
Tue May 12, 2020 6:49 pm
Don't exactly know how that could cause a CEL after a week but the cluster has always acted up for years now.
Cracked solder joint, path or connector got aggravated when you pulled the cluster.
--------
Platform: P80 1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package.
Platform: X40 (Nedcar) 2003 S40, B4204T3, 14T twin scroll AW55-50/51SN, Siemens EMS 2000.
Platform P2 2005 XC90 T6 Executive, B6294T, 4T65 AWD, Bosch Motronic 7.0.
Platform P2 2004 S60R, B2524T4, AW50/51 AWD, B8444S TF80 AWD, Bosch Motronic 7.0, BorgWarner K24 turbocharger. V8 conversion in progress.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post