2001 V70XC - Random stall when coming to a stop... Topic is solved

[xHeart]

The two AP related ECM codes:

MVS_ECM9180.png (129.06 KiB) Viewed 1310 times

The ETM test - cold engine: Difference of up to 13 degrees between the two sensors is permissible. The graph looks very different from that of Precopster's video.

MVS_ETM_test.png (37.61 KiB) Viewed 1310 times

[prwood]

It does seem like your ETM sensors are in good shape, so maybe it really is the pedal sensor.

[xHeart]

It does seem like your ETM sensors are in good shape, so maybe it really is the pedal sensor.

This flow chart puts Engine Management Relay in the mix https://xemodex.com/us/pdf/ETM%20Flow%2 ... -final.pdf

[xHeart]

This thread comes VERY close, a clone, to my situation viewtopic.php?f=9&t=26880

[xHeart]

MAF data at idle was within range, i.e 14 kg/h

Here are clippings from Troubleshooting ETS for respective DTCs: (source: precopster)

[xHeart]

Followed the electronic diagram for component 7/51 via junction point 53/329 to ground 31/93. All looked normal. Picked up new AP PN#30683516. The person said, AP sensor takes relearn procedure plus few drive cycle to tango with ETM - be patient.

Installed AP this morning. Warmed up the engine, let it sit at N for a minute. It ran with few pockets of hesitation for first few miles then felt normal for an hour drive in 25-40 mph zone. Do not apply brake in reaction to AP behavior while it is adapting.

I'll keep an eye on it before grading SUCCESS.

The HOT engine 83-deg/C ETM test reads Max Difference 0.48%. So both, COLD and HOT are now similar.

MAF data at Idle from yesterday:

MVS_MAF_Idle.png (67.54 KiB) Viewed 1246 times

[xHeart]

After a ERASE ALL procedure, clearing any stored DTC, a highway run was in my to-dos. 19 miles into it, raising speed up to 80mph, the gas pedal felt BROKEN -- the sense of a snap was striking. The Limp Home kicked in and the speed dropped to 40-45mph.

No surge issues, however, hesitation at stops (idling at D) were present on drive home. Two DTCs are ECM-9180 (red) & ECM-959F (yellow).

MVS_ECM9180_3029.jpg (245.81 KiB) Viewed 1202 times

I'm searching for corresponding P values for ECM-9180 and ECM-959F?

[xHeart]

Found this:

More Tips;

1999-2000 Volvo C/S/V/XC70

ETS light is on, car goes to “Limp – home” mode and the following codes are stored all at once;

P-1017
P-1019
P-1020
P-1021
P-1043
P-1052

Then you restart the engine all codes “disappear” and the ETS light goes off. Car runs great like nothing ever happened then after a few days its back again.

Replace the “Engine Management” relay located in the smaller auxiliary fuse box located by the left strut tower. Part of this relay’s job is to supply power to the ETM, when it malfunctions it reduces current that is crucial for proper ETM operation. Throttle goes off the CAN Network and the ECM stores the above codes. Once the relay cools down proper current is restored and codes are no longer present.

This is the third time we have come across this problem.

FROM - Chris_Rogers Sep 4th, 2008, 21:31:
P1017=ECM-900E Engine control module (ECM), internal fault, Faulty signal
P1019=ECM-902A Throttle unit communication, Faulty signal
P1020=ECM-902B Throttle unit communication, Faulty signal
P1021=ECM-903F Throttle unit, Faulty signal
P1043=ECM-9520 Accelerator pedal (AP) position sensor, Faulty signal

ALSO:
P1052= ECM- accelerator pedal sensor fault

[abscate]

I might have a spare Engine Management Relay from the parts 99 that should work to test - can you pull your part number?

[xHeart]

I'm suspecting RELAY FMA2 PN #30765045 (9441158). It is likely a cause of tornado on downstream components connected to 11B fuses 4, 5, 6, 7, 8, & 11.

MVS_V70XC_FMA2Relay_.png (83.04 KiB) Viewed 1179 times

See functions directly under control of these fuses -- and triggering Limp Mode.

MVS_V70XC_11BFuses_.png (134.8 KiB) Viewed 1179 times