SwedeSpeed P1 (C30, S40, V50, C70) HID Retrofit Index
- SKBOWE Plug-and-Play harness for P1 HID conversion
- Background info, general questions, and share your HID setup (you are here)
- KBOWE How-To (Original 2009 Version) build your own PWM filter
- Original 2009 investigation and technical discussion on S40 HID issues
- ForceFed’s E46 D2S Bi-Xenon Projector Retrofit guide
- Rewire OEM Bi-Xenon headlights to work on the halogen harness
- DRL Disable Alone not enough for safe Aftermarket HID retrofits
- LizardOfBodom's EU/RHD Bosch ("E46") Bi-Xenon replica retrofitting writeup + angle eyes + running lights
This thread is for general information and nontechnical discussion on HID retrofits in P1 Volvos. If you'd like to share your experiences on an aftermarket HID installation working (or failing!) in a P1 car, that is S40/V50/C30/C70N, please post here!
There is a brief summary of the issues with P1 HID retrofits in the OP (below). If you are planning an HID install and want to do it correctly, just get an skbowe and ignore the warning below. If you are curious why you'd need one, keep reading...
So you want to run HIDs in your Volvo S40, C30, V50, or C70?
UPDATE JUNE 2017 - THE SKBOWE IS NOW AVAILABLE: See skbowe.com for details!
Though they are potentially dangerous, HID retrofits are a popular aftermarket modification which comes up frequently on the S40/V50 forum. There are a number of ways to retrofit: common rebased H11 kits, a complete projector swap, or even fitting the factory bi-xenon housings. The optical performance pros and cons of these methods apply to all vehicles and are discussed ad nauseam elsewhere, so I won't go into them here. This thread covers the specific electrical issues with P1 halogen-to-HID conversion and how to address them. This discussion is NOT relevant to other Volvo models - P1 vehicles with factory equipped bi-xenon headlights, the older P2 (S60, V70), or the newer P3 XC60 and XC90 SUVs - all which have an unrelated lighting electrical system.
This topic deserves a "Told Ya So" disclaimer:
WARNING: Do not attempt to operate an aftermarket HID kit in a Volvo P1 S40 / V50 / C30 / C70 without an SKBOWE before reading and understanding the issue(s) described below. While a kit may turn on, the PWM voltage regulation will drastically shorten the life of the HIDs, and can potentially damage the Windshield Wiper Motor Module (WMM) and/or the Central Electronic Module (CEM), both of which cost several hundred dollars to replace at the dealer.
Headlights are specialized equipment: the HID conversion process is complex, potentially illegal, and risks damaging the vehicle. While this risk can be greatly reduced by following the guidance below, there is no completely safe HID retrofit for P1 cars.
The information summarized here is based on the S40/V50 electrical design document (section on headlights starts on page 21), the factory wiring diagram - group 35 (page 59), the CEM overview, design, and function pages from ViDA confirmed with hardware teardown, and 5+ years of community research (in this thread, also here, here, and various international forums).
A much more thorough technical narrative is available on the skbowe website.
What's the problem?
As with many modern vehicles, aftermarket HID ballasts will not function correctly when directly connected to factory wiring in Volvo P1 chassis vehicles originally equipped with halogen (incandescent) projector headlights. However, the typical "error cancelers" or "canbus harness" - sold by major HID vendors as a generic solution to similar issues in other makes/models - are not appropriate for P1 cars due to their unique electrical system.
Specifically, the each halogen low-beam/DRL combo bulb is directly wired to the CEM (central electronic module), which houses two independent fuseless current-monitored high-side PMOS-switched PWM-voltage-regulated circuits. When an fault condition is detected in either circuit, the CEM signals a "Bulb Failure Low Beam" message (aka bulb-out warning, or BOW) to appear on the DIM (driver information module aka gauge cluster LCD) with a yellow triangle.
Unlike many other vehicles, the fault monitoring in the P1 CEM is very selective to both output current and voltage. The PWM regulation is a much lower frequency (80hz) than the typical 1-200 kHz found elsewhere. Worse still, there is a poorly designed filter in the sensitive Wiper Motor computer (WMM) which shares a ground connection with the right headlight - such that back EMF transients and stray EMI from unshielded high-voltage ballast connections can cause (potentially permanent) erratic wiper behavior.
In short, installing an HID retrofit will cause great anger amongst the notorious Volvo electrical gremlins.
Ok, so what do I do?
It's impractical to fit the OE bi-xenon system, as it would require a new engine and body wiring harness, the GDL modules, the headlight housings, level sensors, and a custom CEM flash that would have to come from VolvoHQ as a factory equipment correction
The safest option is to upgrade your halogen H11 bulbs to H9 and avoid all this trouble.
Using a high-quality (12 AWG) relay harness solves issues (1) and (2) below - the relay harness bypasses the PWM modulation produced by the CEM, so no filtering is necessary. A small "anti-buzz" capacitor may be required on the relay. Do not skimp on the ground, go all the way to the left side strut (nearest the battery). Using a relay harness will result in the "Bulb Failure" message, which is harmless but annoying. To eliminate it, both headlight circuits must see a 25-30W load: so either use 5-ohm load resistors (which wastes 30W of power per) or run the headlight wires to the foglight bulbs (which may not be legal in jurisdictions where cars are limited to 4 forward facing lights on simultaneously.
If you're still reading, you probably want to use the factory wiring with an aftermarket ballast. This is possible, but you have to address the three main issues:
(1) PWM Voltage Regulation
To extend the life of the higher-wattage halogen bulbs used in our cars (low-beams, running lights, brake lights, turn signals, and reverse lights), Volvo engineers decided to add a form of voltage regulation called Pulse Width Modulation (PWM) - which switches the 14.5V DC produced by the alternator on and off around 80 times per second to produce an average of 13V. While halogen bulbs don't mind these pulses, this form of regulation prevents aftermarket HID ballasts hooked to the factory halogen low-beam wiring from operating correctly. There is an extremely detailed explanation of this issue in my original research thread.
There are two levels of PWM regulation. All bulbs are regulated to 13.0V max, which is a duty cycle of about 80% under normal operation. In addition, cars programed with Daytime Running Lights (DRL) will drop further to around 8.5V using a 50-60% duty cycle when the sunlight sensor (located in the center of the dash) decides that it is day time and the Light Switch Module is in position "0". No automotive HID ballast is designed to run on 8.5V, so retrofits using the OEM wiring should only be operated in position II (on). But even in this position, the 80% duty cycle PWM, producing an average of 13v, is problematic.
Use a diode-capacitor half-bridge rectifier to smooth the PWM to a clean DC voltage. Due to the low frequency (80 Hz) modulation the capacitor must be very large - on the order of 33,000uF or more - to achieve adequate ripple filtration. Details of how such a filter can be DIY'ed are in the KBOWE thread. The KBOWE addresses the (2) ground issue, but not the (3) EMI issue.
The KBOWE is very successful when used with large capacitors. For the record, there have been
twothree (as of 12/2019) recorded WMM failures with KBOWEs, both cases, a full KBOWE and a mini KBOWE pair were my fault for suppling smaller 22,000uF filter capacitors. They occurred after an extended duration and a switch to low-quality ballasts (the other ballasts having failed presumably due to degraded filter capacitors). The use of high-quality, 33,000uF+ capacitors is of the upmost importance.
As of December 2019: A third report of a failed WMM with KBOWE was posted in this thread with 33,000uF capacitors. It seems that they did not follow the grounding instructions below, possibly out of confusion between KBOWE, SKBOWE, and Mini-KBOWE. To date, none of the 42,000uF, grounded SKBOWEs have had issues.
As of December 2016: there are no commercial products that I am aware of that can handle the DRL PWM (if this changes I'll post it here). The 2,200 uF in "HID-elim", 4,700uF capacitor in the DDM BOW3 and the 6,300uF capacitor in the Morimoto CANBUS harness are just an order of magnitude too small for this exceptionally low frequency. They don't reduce ripple enough to begin with, and even if they do work initially 4A+ ripple currents far exceed their ratings resulting in premature failure. When they fail, the ballast will either shut down (best case) or try to re-ignite the bulb many times per second producing damaging levels of EMF and RF noise.
Update regarding DRL disable: DRL disable alone is NOT sufficient to allow safe HID retrofit. For many years, the advice has been that, if there are no legal DRL requirements in your area, software update PN 30679690 will disable both DRLs and the DAYTIME PWM regulation (60% duty cycle). Depending on the dealer, this flash will run between $75-$150. However, recent testing has shown that that *just* disabling DRLs DOES NOT eliminate the 13.0V-regulating (~90% dt) PWM, and does not address the (2) ground or (3) EMI issues below. Many DRL-disable-only retrofits have had WMM failure, and this new data explains why. To be clear - the only effective solution to Problem (1) is a KBOWE until a commercial alternative is developed.
(2) Shared Ground Connection / LV EMI
The right headlight (left hand if looking at the car from the front) H11 connector shares a ground connection with the Wiper Motor (WMM), which is digitally controlled via a LIN signal from the CEM. A badly behaved ballast (e.g. with a failing error harness) will introduce voltage spikes (also called transients) into the electrical system, which can cause communication problems and potentially permanent damage to the WMM.
The ground point in question is actually not near the WMM, it's at the passenger-side strut. You can follow it in the full 2005 S40/V50 wiring diagram I have on my site:
Page 26: The ground point 31/110 is listed as "Right MacPherson strut tower"
Page 59: The headlight (group 35) low beams, specifically right side 10/2, ground via junction 63/109 -> junction 63/108 -> ground point 31/110 (right strut)
Page 74: WMM (6/1) grounds through pin3 -> junction 63/108 -> ground point 31/110 (right strut tower). The CEM itself grounds at A:14 -> junction 63/12 -> ground point 31/84 (passenger side A-post)
Page 171: The junction 63/108 is buried in the engine harness, right side with a good amount of distance to the ground point 31/110
It's the parasitic resistance between 63/108 and 31/110 which allows voltage to develop between the CEM ground and the WMM ground, potentially bringing the LIN bus voltage on pin 1 negative enough to forward bias the clamp diodes.
Note that, similarly, the foglight ground is shared with the PSM (electronic power steering pump) and some members have had issues with "Power steering failure" messages running retrofits off the fog circuit.
Add a new low-impedance ground point for the HID ballasts so that current does not flow through the factory ground path, and add some bypass capacitance to mitigate transients.
The SKBOWE and the mini KBOWE include an auxiliary ground connection to serve this purpose, and have sufficient capacitance (from the ripple filter) to address any transients.
For additional protection, metal ballasts with grounded cases (not all are - check with multimeter first) should be physically bolted to the chassis after stripping paint around the screw holes (be sure to repaint after it's installed!).
The HID ballast can ground pretty much anywhere, the shorter the connection the better. Use high quality #12 wire and avoid using the terminals on the right-side strut tower (opposite the battery). Take care to clean the contact area down to bare shiny metal - it is critical that this connection be low resistance.
(3) Ballast HV EMI
This is the least-well defined problem, and while it has been discussed at length (e.g. here and here and here) with widely varying opinions, so far there is no concrete evidence to support the theory: In general, older/less expensive ballasts have poor shielding on the HV ignitor and wires, essentially turning the system into a radio transmitter which can cause electromagnetic interference (EMI or RFI) with other electronics in the vehicle. Usually this just results in FM radio noise, but in some vehicles (with no relation to the P1 electrical system) insufficient shielding has been shown to affect computer modules (including the wiper motor) due to the increased EMI levels.
Best practice - regardless of vehicle - is to select high-quality retrofit components including shielded on HV circuits (between the ignitor and the bulb). The D1S configuration (bulb-integrated ignitor) used in the factory bi-xenon setup offers the best EMI shielding possible, but may be difficult to retrofit in the halogen housing. Some manufactures produce D2S on-bulb ignitor, shielded external D2S ignitor, and rebased shielded ballast kits. Alternately, a less expensive kit can be shielded by wrapping copper or aluminum foil around the HV leads to form a faraday cage and grounding it to the chassis.
If the above is just all too much,
my recommendation would be to hold off on an HID retrofit. Some day there might be a safe, plug-and-play solution, but as of 5/2016 there isn't one. Sorry
UPDATE JUNE 2017 - A LIMITED RUN OF SKBOWE WILL BE PRODUCED: See skbowe.com for details on a plug-and-play solution
For increased performance, you can upgrade your halogen lights.
My retrofit is working fine, how can I help?
I'm trying to get some data together on HID installs in the C30/S40/V50/C70 chassis, and if you have installed an HID kit (sorry, factory bi-xenon's don't count) I would appreciate your help!
(1) When you installed the kit (approximately, like a year ago, a month ago, etc...)
(2) If the kit is 35w or 55w (if you're not sure it's probably 35w), and the brand if you remember.
(3) If you are running a battery harness, BOW eliminator, DRL disable etc... and is the "Low beam failure" message still displayed.
Also, if you have had to replace your wiper motor (WMM) after installing your HID kit, (a) how long after and (b) how many times it has been replaced would be much appreciated. Thanks!
Edit: BTW data is here in-case anyone is curious: http://theeshadow.com/files/volvo/p1hid.xls