IPDVolvo PartsVolvo Salvage: Used Volvo Parts and Over 50 Years ExperienceSouthern Vo Vo sells genuine used Volvo parts
Volvo Parts

Buying gifts? Please use this Amazon link ... and help keep MVS on the Web. Thank you!Amazon.com

MVS Login

Register - it's Free!

Get Help

Please read the Help Page. Then read the forum FAQ. If you've tried those and still have a question, please contact Matt.

Volvo Parts
Shopping Amazon.com? Help MVS by using this link!
tirerack-mvs-ad.png

Camshaft Position Sensor Circuit

Help and Advice on Volvo's extremely popular car line, powered by Volvo's nearly indestructible, versatile 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

Camshaft Position Sensor Circuit

Postby emtbjb » 22 Jul 2010, 04:27

I have a 1998 V70-XC that will not start. I have checked the crankshaft sensor, the camshaft sensor and the coil by the book. All the sensors test out ok, but when I tested the camshaft position sensor circuit, plug 1 test with good ground, wire 3 was battery voltage, but wire 2 was also battery voltage. According to the testing procedure, wire 2 was supposed to have 0-5 volts. I check the wires and there was no short. What I want to know, is the ECU shorted out or is there something else? Also, I replaced the ignition switch with a new one. Does anyone have any experience with this?
emtbjb
 
Posts: 3
Joined: 20 Jul 2010, 15:30
Location: Iowa
Model and Year: 1990 760 GLE

Re: Camshaft Position Sensor Circuit

Postby Ozark Lee » 22 Jul 2010, 04:38

Welcome to MVS,

How are you testing this? Is the sensor plugged in or are you just plugging your meter into the connector that goes to the sensor with the sensor unplugged?

The proper procedure is to backprobe the connector with the sensor plugged in. If that is indeed what you are doing the sensor is bad and it will prevent the car from starting.

...Lee
'94 850 N/A
'96 850 N/A
'96 Platinum Edition Turbo
'98 S70 T5
'99 V70XC
Previous: 1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
User avatar
Ozark Lee
MVS Moderator
MVS Moderator
 
Posts: 11657
Joined: 07 Sep 2006, 14:24
Location: USA Midwest

Re: Camshaft Position Sensor Circuit

Postby 850tech » 22 Jul 2010, 04:56

Just took a quick look on alldata and those values are correct, with the sensor disconnected B+ (12v) on 2 and 3, and ground on 1 edit: on the engine harness side obviously

Any Codes? If so post them and me or someone else here wil let you know where to look as soon as possible. Also have you checked all your basics?
Fuel, spark and injector pulse? we need to know so you can narrow it down. For example if you have fuel, but no spark or injector pulse them a crank or cam sensor could be the issue, but you don't want to get into the complicated when something as simple is as the fuel pump relay (most common) could cause the same no start issue. Let us know if it's fuel or spark your missing, and don't worry about injector pulse, I understand most don't have that kind of test equipment.
I'm sure we will be able to help you figure it out.
850tech
Forum Member
Forum Member
 
Posts: 123
Joined: 07 May 2010, 23:58
Location: Canada
Model and Year: 1995 850 Turbo 5spd

Re: Camshaft Position Sensor Circuit

Postby emtbjb » 22 Jul 2010, 15:22

I am testing the camshaft position sensor with a meter plugged into the connector that goes to the ECU. This is according to the test procedure by Chilton, Hayes, and Volvo. It calls for testing the values at the harness on the engine side unplugged from the sensor. I do not have an account with Alldata. I have pulled a P0340 code. I have good fuel pressure, no spark, and have not checked the injector pulse yet. When I do backprobe the camshaft sensor and crank it, 3 has battery volt, 2 goes between battery volt and 6.5 volts.
emtbjb
 
Posts: 3
Joined: 20 Jul 2010, 15:30
Location: Iowa
Model and Year: 1990 760 GLE

Re: Camshaft Position Sensor Circuit

Postby 850tech » 24 Jul 2010, 03:34

I'm really sorry it's taken me so long to reply, with all the heat lately lots of cars have been breaking down and I've been working extra hours.

Here's the diagnostic procedure for P0340, which is a cam sensor fault, as I'm sure you know. Don't bother checking for pulse as with P0340 you won't have it. Go through this step by step and you should find your fault. The voltage change on pin 2 would suggest the cam sensor magnet is picking up the cam rotation, but that does not mean the signal is clean or it's frequency is correct, so if all the wiring checks out I would go ahead and replace the sensor.


Checking Ground Lead

Ignition off.
Wait for approx. 150 seconds (cars with immobilizer 245 seconds).
Disconnect the camshaft position (CMP) sensor.
Connect an ohmmeter between the camshaft position sensor connector 1 (engine control module (ECM) side) and ground.
The ohmmeter should read approx. 0 ohms .
If reading is OK:

Proceed to Checking Power Cable section below.
If reading is incorrect:

Proceed to test step below.

Checking The Engine Control Module Connector

Ignition off.
Camshaft position sensor disconnected.
Check engine control module connector for contact resistance and oxidation.
Engine control module connected.
Connect an ohmmeter between the camshaft position sensor connector 1 (engine control module side) and ground.
The ohmmeter should read approx. 0 ohms .
If reading is OK:

The diagnostic trouble code (DTC) was caused by poor contact in the engine control module connector.
Then proceed to Verification section below.
If reading is incorrect:

Check cable between camshaft position sensor terminal 1 and engine control module # A18 for an open-circuit.
Then proceed to Verification section below.

Checking Power Cable

Ignition on.
Camshaft position sensor disconnected.
Connect a voltmeter between the camshaft position sensor connector 3 (engine control module side) and ground.
The voltmeter should read battery voltage .
If reading is OK:

Proceed to Checking Signal Cable section below.
If reading is incorrect:

Proceed to test step below.

Checking The Engine Control Module Connector

Ignition off.
Camshaft position sensor disconnected.
Check engine control module connector for contact resistance and oxidation.
Engine control module connected.
Ignition on.
Connect a voltmeter between the camshaft position sensor connector 3 (engine control module side) and ground.
The voltmeter should read battery voltage .
If reading is OK:

The diagnostic trouble code was caused by poor contact in the engine control module connector.
Then proceed to Verification section below.
If reading is incorrect:

Check cable between camshaft position sensor terminal 3 and engine control module # A36 for an open-circuit.
Then proceed to Verification section below.

Checking Signal Cable

Ignition on.
Camshaft position sensor disconnected.
Connect a voltmeter between the camshaft position sensor connector 2 (engine control module side) and ground.
The voltmeter should read battery voltage .
If reading is OK:

Proceed to test step below.
If reading is incorrect:

Proceed to Checking Signal Cable Resistance to Ground section below.

Checking The Signal Cable Voltage

Ignition on.
Camshaft position sensor disconnected.
Connect a test light between camshaft position connector terminal 2 (engine control module side) and ground.
Does the test light light up ?
Yes:

Check cable between the camshaft position sensor terminal 2 and engine control module # A21 for a short-circuit to supply voltage.
Then proceed to Verification section below.
No:

Proceed to Check Of The Camshaft Position Sensor section below.

Checking Signal Cable Resistance to Ground

Ignition off.
Wait for approx. 150 seconds (cars with immobilizer 245 seconds).
Camshaft position sensor disconnected.
Connect an ohmmeter between the camshaft position sensor connector 2 (engine control module side) and ground.
Is resistance Infinite ?
Yes:

Proceed to test step below.
No:

Check cable between the camshaft position sensor terminal 2 and engine control module # A21 for a short-circuit to ground.
Then proceed to Verification section below.

Checking The Engine Control Module Connector

Ignition off.
Camshaft position sensor disconnected.
Check engine control module connector for contact resistance and oxidation.
Engine control module connected.
Connect an ohmmeter between the camshaft position sensor connector 2 (engine control module side) and ground.
The ohmmeter should read 0.5 - 3.0 k ohms .
If reading is OK:

The diagnostic trouble code was caused by poor contact in the engine control module connector.
Then proceed to Verification section below.
If reading is incorrect:

Check cable between the camshaft position sensor terminal 2 and engine control module # A21 for an open-circuit.
Then proceed to Verification section below.

Check Of The Camshaft Position Sensor

Connect the camshaft position sensor.
Try to start the engine.
Does the engine start ?
Yes:

The cause of the diagnostic trouble code is poor contact in the camshaft position sensor connector and/or the engine control module connector. Check connectors for contact resistance and oxidation.
Then proceed to Verification section below.
No:

Try a new camshaft position sensor.
Then proceed to Verification section below.

Checking Camshaft Position Sensor Signal

The camshaft position sensor can malfunction due to a short-circuit to supply voltage in the signal cable. Check camshaft position sensor as follows.
Connect the camshaft position sensor.
Try to start the engine.
Does the engine start ?
Yes:

Camshaft position sensor OK.
No:

Try a new camshaft position sensor.
Then proceed to Verification section below.

Verification

After carrying out the repair, check that the fault has been remedied as follows.
Ignition off.
Reconnect connectors, reinstall components.
Try to start the engine.
Does the engine start ?
Yes:

Fault corrected
No:

Proceed to test step below.
Fault-tracing Information
The verification result shows that the fault persists.

Do you want to exit fault-tracing?
Yes:

Fault not corrected
No:

Return to Checking Ground Lead section above.
850tech
Forum Member
Forum Member
 
Posts: 123
Joined: 07 May 2010, 23:58
Location: Canada
Model and Year: 1995 850 Turbo 5spd

Re: Camshaft Position Sensor Circuit

Postby emtbjb » 30 Jul 2010, 17:03

I worked. She lives again. Thank you so much for the help. It's nice to have received the correct information. Chilton has the wrong voltage for wire #2. You've saved me lot of $ and time.
emtbjb
 
Posts: 3
Joined: 20 Jul 2010, 15:30
Location: Iowa
Model and Year: 1990 760 GLE

Re: Camshaft Position Sensor Circuit

Postby 850tech » 31 Jul 2010, 00:52

Your welcome, and thank you for posting a follow up so people searching for information on this code in the future know this thread lead to a successful diagnosis. There is nothing worse then reading a page or two of post that look promising, only to have the topic suddenly end with no resolution, leaving you wondering if any of the solutions worked, and more importantly if any are worth spending time and money on.
850tech
Forum Member
Forum Member
 
Posts: 123
Joined: 07 May 2010, 23:58
Location: Canada
Model and Year: 1995 850 Turbo 5spd

Re: Camshaft Position Sensor Circuit

Postby lhailah » 25 Sep 2011, 18:57

850tech, great steps, thanks a lot for sharing that. I have the same code reading and try to diagnos this way. however i'm stuck at the Check cable between camshaft position sensor terminal 3 and engine control module # A36 for an open-circuit.
I know where the ecu is but how do I find to connect to #A36. I've never got into the computer compartment before and dont know what to expect under those silver boxes.

Is this step to tell me if there is a problem with the computer or the wires. wouldn't i get other trouble codes if there were a problem with the computer?
lhailah
Forum Member
Forum Member
 
Posts: 36
Joined: 04 Nov 2010, 15:54
Location: new york
Model and Year: XC70, 1998

Re: Camshaft Position Sensor Circuit

Postby BEJinFbk » 25 Sep 2011, 21:21

850tech - Great writeup! Nice list. Someone should get this into the database. :wink:

FWIW, I came out to my car a few days ago and after only 5 minutes, it wouldn' start. It just spun.
I always carry my reader ( Isn't that what the pockets on the seatbacks are for? ) and got P0340.
I opened the hood, unplugged the CPS and plugged it back in. Voila! That's all the attention it wanted.
Reseating the connector is always worth a shot... :mrgreen:
'98 V70 R - Well Equipped for Life Up North... ;)
User avatar
BEJinFbk
Senior Forum Member
Senior Forum Member
 
Posts: 2655
Joined: 06 Jan 2008, 05:32
Location: Fairbanks, Alaska
Model and Year: '98 V70 R

Re: Camshaft Position Sensor Circuit

Postby lhailah » 28 Sep 2011, 01:29

i wish it were that simple for me.
installed new cam and crank sensor and still no spark. Had my two mechanic buddies check it out and nothing.
CAn anyone shed some light?
lhailah
Forum Member
Forum Member
 
Posts: 36
Joined: 04 Nov 2010, 15:54
Location: new york
Model and Year: XC70, 1998

Re: Camshaft Position Sensor Circuit

Postby socompsp » 06 Jun 2013, 09:34

have you looked into the ignition coil? what about fuses and relays? also, how clean are the connectors for those sensors?
RIP: My Father 10/17/13 The Spiegel Grove claims another Soul.
"We are all the sum of our choices. The fear is not of dying... it is to not have lived."
Forever loved. Never Forgotten.
socompsp
Forum Member
Forum Member
 
Posts: 146
Joined: 13 May 2013, 03:13
Location: orlando
Model and Year: c70 HPT 1998

Re: Camshaft Position Sensor Circuit

Postby 15Murft » 28 Jan 2014, 17:09

I love it here. Just joined. Hope to participate as much as possible. What a great thread !
15Murft
New Member
New Member
 
Posts: 10
Joined: 26 Jan 2014, 01:28
Location: Hamburg, New York, USA
Model and Year: S60 2008, S70 1998


Save thousands off MSRP on your new car.

Return to Volvo 850, S70, V70, C70 & V70-XC Forum (1992-2000)

Who is online

Users browsing this forum: alschnertz, AVIP, cbdbcbdb, deepsouth, epukerob, Google [Bot], Google Adsense [Bot], JimBee, SAR, sgroper46, steamnjn23, volvooh and 127 guests